(Based on Original Glimmer Library Handling World’s Ruby GUI Needs Since 2007. Beware of Imitators!)
(Talk Videos: Intro to Ruby in the Browser & Frontend Ruby with Glimmer DSL for Web)
You can finally have Ruby developer happiness and productivity in the Frontend! No more wasting time splitting your resources across multiple languages, using badly engineered, over-engineered, or premature-optimization-obsessed JavaScript libraries, fighting JavaScript build issues (e.g. webpack), or rewriting Ruby Backend code in Frontend JavaScript. With Ruby in the Browser, you can have an exponential jump in development productivity (2x or higher), time-to-release (1/2 or less time), cost (1/2 or cheaper), and maintainability (~50% the code that is simpler and more readable) over JavaScript libraries like React, Angular, Ember, Vue, and Svelte, while being able to reuse Backend Ruby code as is in the Frontend for faster interactions when needed. Ruby in the Browser finally fulfills every highly-productive Rubyist's dream by bringing fun to Frontend Development, the same fun you had for years and decades in Backend Development.
Glimmer DSL for Web enables building Web Frontends using Ruby in the Browser, as per Matz's recommendation in his RubyConf 2022 keynote speech to replace JavaScript with Ruby. It supports Rails' principle of the One Person Framework by not requiring any extra developers with JavaScript expertise, yet enabling Ruby (Backend) Software Engineers to develop the Frontend with Ruby code that is better than any JavaScript code produced by JS developers. It aims at providing the simplest, most intuitive, most straight-forward, and most productive frontend framework in existence. The framework follows the Ruby way (with DSLs and TIMTOWTDI) and the Rails way (Convention over Configuration) in building Isomorphic Ruby on Rails Applications. It provides a Ruby HTML DSL, which uniquely enables writing both structure code and logic code in one language. It supports both Unidirectional (One-Way) Data-Binding (using <=) and Bidirectional (Two-Way) Data-Binding (using <=>). Dynamic rendering (and re-rendering) of HTML content is also supported via Content Data-Binding. Modular design is supported with Glimmer Web Components. And, a Ruby CSS DSL is supported with the included Glimmer DSL for CSS. Many samples are demonstrated in the Rails sample app (there is a very minimal Standalone [No Rails] static site sample app too). You can finally live in pure Rubyland on the Web in both the frontend and backend with Glimmer DSL for Web!
Glimmer DSL for Web aims to be a very simple Ruby-based drop-in replacement for your existing JavaScript Frontend library (e.g. React, Angular, Vue, Ember, Svelte) or your JavaScript Frontend layer in general. It does not change how your Frontend interacts with the Backend, meaning you can continue to write Rails Backend API endpoints as needed and make Ajax HTTP requests or read data embedded in elements, but from Ruby in the Browser. Whatever is possible in JavaScript is possible when using Glimmer DSL for Web as it integrates with any existing JavaScript library. The Rails sample app demonstrates how to make Ajax HTTP calls and how to integrate with a JavaScript library (highlightjs) that performs code syntax highlighting.
After looking through the samples below, read the FAQ (Frequently Asked Questions) to learn more about how Glimmer DSL for Web compares to other approaches/libraries like Hotwire (Turbo), Phlex, ViewComponent, Angular, Vue, React, Svelte, and other JS frameworks.
(Attention Software Engineers, Bloggers, and Contributors: Please use Glimmer DSL for Web in web projects, blog about it, and submit a PR with your article, project, and/or open-source-repo added to the README. Also, I give everyone permission to present this project at their local Ruby user group, local Software Engineering meetup, or Software Conferences outside of North America (e.g. Europe). I am willing to present at Software Conferences in North America and Japan (the birthplace of Ruby) only. If you want to have this project presented elsewhere, like in Europe or South America, feel free to prepare and give your own presentations of the project, and if needed, hit me up for help on the Glimmer Gitter chat)
Hello, World! Sample
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
div {
'Hello, World!'
}
endThat produces the following under <body></body>:
<div data-parent="body" class="element element-1">
Hello, World!
</div>
You can also mount the div elsewhere by passing the parent: parent_css_selector option (e.g. div(parent: 'div#app-container') { 'Hello, World!' }).
Hello, Button!
Event listeners can be setup on any element using the same event names used in HTML (e.g. onclick) while passing in a standard Ruby block to handle behavior. $$ gives access to JS global scope from Ruby to invoke functions like alert.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
div {
button('Greet') {
onclick do
$$.alert('Hello, Button!')
end
}
}
endThat produces the following under <body></body>:
<div data-parent="body" class="element element-1">
<button class="element element-2">Greet</button>
</div>Screenshot:
Hello, Form!
Glimmer DSL for Web gives access to all Web Browser built-in features like HTML form validations, input focus, events, and element functions from a very terse and productive Ruby HTML DSL. Also, you can apply CSS styles by including directly in Ruby code as a string, using Glimmer DSL for CSS, or managing CSS completely separately using something like SCSS. The CSS techniques could be combined as well, like by managing common reusable CSS styles separately in SCSS, but adding component specific CSS styles in Ruby when it is more convenient.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
div {
h1('Contact Form')
form {
div {
label('Name: ', for: 'name-field')
@name_input = input(type: 'text', id: 'name-field', required: true, autofocus: true)
}
div {
label('Email: ', for: 'email-field')
@email_input = input(type: 'email', id: 'email-field', required: true)
}
div {
input(type: 'submit', value: 'Add Contact') {
onclick do |event|
if ([@name_input, @email_input].all? {|input| input.check_validity })
# re-open table content and add row
@table.content {
tr {
td { @name_input.value }
td { @email_input.value }
}
}
@email_input.value = @name_input.value = ''
@name_input.focus
end
end
}
}
}
h1('Contacts Table')
@table = table {
tr {
th('Name')
th('Email')
}
tr {
td('John Doe')
td('johndoe@example.com')
}
tr {
td('Jane Doe')
td('janedoe@example.com')
}
}
# CSS Styles
style {
# CSS can be included as a String as done below, or as Glimmer DSL for CSS syntax (Ruby code) as done in other samples
<<~CSS
input {
margin: 5px;
}
input[type=submit] {
margin: 5px 0;
}
table {
border:1px solid grey;
border-spacing: 0;
}
table tr td, table tr th {
padding: 5px;
}
table tr:nth-child(even) {
background: #ccc;
}
CSS
}
}
endThat produces the following under <body></body>:
<div data-parent="body" class="element element-1">
<h1 class="element element-2">Contact Form</h1>
<form class="element element-3">
<div class="element element-4">
<label for="name-field" class="element element-5">Name: </label>
<input type="text" id="name-field" required="true" autofocus="true" class="element element-6">
</div>
<div class="element element-7">
<label for="email-field" class="element element-8">Email: </label>
<input type="email" id="email-field" required="true" class="element element-9">
</div>
<div class="element element-10">
<input type="submit" value="Add Contact" class="element element-11">
</div>
</form>
<h1 class="element element-12">Contacts Table</h1>
<table class="element element-13">
<tr class="element element-14">
<th class="element element-15">Name</th>
<th class="element element-16">Email</th>
</tr>
<tr class="element element-17">
<td class="element element-18">John Doe</td>
<td class="element element-19">johndoe@example.com</td>
</tr>
<tr class="element element-20">
<td class="element element-21">Jane Doe</td>
<td class="element element-22">janedoe@example.com</td>
</tr>
</table>
<style class="element element-23">
input {
margin: 5px;
}
input[type=submit] {
margin: 5px 0;
}
table {
border:1px solid grey;
border-spacing: 0;
}
table tr td, table tr th {
padding: 5px;
}
table tr:nth-child(even) {
background: #ccc;
}
</style>
</div>Screenshot:
Hello, Data-Binding!
Glimmer DSL for Web intuitively supports both Unidirectional (One-Way) Data-Binding via the <= operator and Bidirectional (Two-Way) Data-Binding via the <=> operator, incredibly simplifying how to sync View properties with Model attributes with the simplest code to reason about.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
Address = Struct.new(:street, :street2, :city, :state, :zip_code, keyword_init: true) do
STATES = {...} # contains US States
def state_code
STATES.invert[state]
end
def state_code=(value)
self.state = STATES[value]
end
def summary
string_attributes = to_h.except(:billing_and_shipping)
summary = string_attributes.values.map(&:to_s).reject(&:empty?).join(', ')
summary += " (Billing & Shipping)" if billing_and_shipping
summary
end
end
@address = Address.new(
street: '123 Main St',
street2: 'Apartment 3C, 2nd door to the right',
city: 'San Diego',
state: 'California',
zip_code: '91911',
billing_and_shipping: true,
)
include Glimmer
Document.ready? do
div {
div(style: 'display: grid; grid-auto-columns: 80px 260px;') { |address_div|
label('Street: ', for: 'street-field')
input(id: 'street-field') {
# Bidirectional Data-Binding with <=> ensures input.value and @address.street
# automatically stay in sync when either side changes
value <=> [@address, :street]
}
label('Street 2: ', for: 'street2-field')
textarea(id: 'street2-field') {
value <=> [@address, :street2]
}
label('City: ', for: 'city-field')
input(id: 'city-field') {
value <=> [@address, :city]
}
label('State: ', for: 'state-field')
select(id: 'state-field') {
Address::STATES.each do |state_code, state|
option(value: state_code) { state }
end
value <=> [@address, :state_code]
}
label('Zip Code: ', for: 'zip-code-field')
input(id: 'zip-code-field', type: 'number', min: '0', max: '99999') {
# Bidirectional Data-Binding with <=> ensures input.value and @address.zip_code
# automatically stay in sync when either side changes
# on_write option specifies :to_s method to invoke on value before writing to model attribute
# to ensure the numeric zip code value is stored as a String
value <=> [@address, :zip_code,
on_write: :to_s,
]
}
div(style: 'grid-column: 1 / span 2') {
input(id: 'billing-and-shipping-field', type: 'checkbox') {
checked <=> [@address, :billing_and_shipping]
}
label(for: 'billing-and-shipping-field') {
'Use this address for both Billing & Shipping'
}
}
# Programmable CSS using Glimmer DSL for CSS
style {
# `r` is an alias for `rule`, generating a CSS rule
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
div(style: 'margin: 5px') {
# Unidirectional Data-Binding is done with <= to ensure @address.summary changes
# automatically update div.inner_text
# (computed by changes to address attributes, meaning if street changes,
# @address.summary is automatically recomputed.)
inner_text <= [@address, :summary,
computed_by: @address.members + ['state_code'],
]
}
}
endScreenshot:
Hello, Content Data-Binding!
If you need to regenerate HTML element content dynamically, you can use Content Data-Binding to effortlessly rebuild HTML elements based on changes in a Model attribute that provides the source data. In this example, we generate multiple address forms based on the number of addresses the user has.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
class Address
attr_accessor :text
attr_reader :name, :street, :city, :state, :zip
def name=(value)
@name = value
update_text
end
def street=(value)
@street = value
update_text
end
def city=(value)
@city = value
update_text
end
def state=(value)
@state = value
update_text
end
def zip=(value)
@zip = value
update_text
end
private
def update_text
self.text = [name, street, city, state, zip].compact.reject(&:empty?).join(', ')
end
end
class User
attr_accessor :addresses
attr_reader :address_count
def initialize
@address_count = 1
@addresses = []
update_addresses
end
def address_count=(value)
value = [[1, value.to_i].max, 3].min
@address_count = value
update_addresses
end
private
def update_addresses
address_count_change = address_count - addresses.size
if address_count_change > 0
address_count_change.times { addresses << Address.new }
else
address_count_change.abs.times { addresses.pop }
end
end
end
@user = User.new
include Glimmer
Document.ready? do
div {
div {
label('Number of addresses: ', for: 'address-count-field')
input(id: 'address-count-field', type: 'number', min: 1, max: 3) {
value <=> [@user, :address_count]
}
}
div {
# Content Data-Binding is used to dynamically (re)generate content of div
# based on changes to @user.addresses, replacing older content on every change
content(@user, :addresses) do
@user.addresses.each do |address|
div {
div(style: 'display: grid; grid-auto-columns: 80px 280px;') { |address_div|
[:name, :street, :city, :state, :zip].each do |attribute|
label(attribute.to_s.capitalize, for: "#{attribute}-field")
input(id: "#{attribute}-field", type: 'text') {
value <=> [address, attribute]
}
end
div(style: 'grid-column: 1 / span 2;') {
inner_text <= [address, :text]
}
style {
r(address_div.selector) {
margin '10px 0'
}
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} label") {
grid_column '1'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
}
end
end
}
}
endScreenshot:
Hello, Component!
You can define Glimmer web components (View components) to reuse visual concepts to your heart's content,
by simply defining a class with include Glimmer::Web::Component and encasing the reusable markup inside
a markup {...} block. Glimmer web components automatically extend the Glimmer HTML DSL with new keywords
that match the underscored versions of the component class names (e.g. an OrderSummary class yields
the order_summary keyword for reusing that component within the Glimmer HTML DSL).
You may insert a Glimmer component anywhere into a Rails View using glimmer_component(component_path, *args)
Rails helper (more about it in Hello, glimmer_component Rails Helper!).
Below, we define an AddressForm component that generates an address_form keyword, and then we
reuse it twice inside an AddressPage component displaying a Shipping Address and a Billing Address.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
Address = Struct.new(:full_name, :street, :street2, :city, :state, :zip_code, keyword_init: true) do
STATES = {
"AK"=>"Alaska",
"AL"=>"Alabama",
"AR"=>"Arkansas",
"AS"=>"American Samoa",
"AZ"=>"Arizona",
"CA"=>"California",
"CO"=>"Colorado",
"CT"=>"Connecticut",
"DC"=>"District of Columbia",
"DE"=>"Delaware",
"FL"=>"Florida",
"GA"=>"Georgia",
"GU"=>"Guam",
"HI"=>"Hawaii",
"IA"=>"Iowa",
"ID"=>"Idaho",
"IL"=>"Illinois",
"IN"=>"Indiana",
"KS"=>"Kansas",
"KY"=>"Kentucky",
"LA"=>"Louisiana",
"MA"=>"Massachusetts",
"MD"=>"Maryland",
"ME"=>"Maine",
"MI"=>"Michigan",
"MN"=>"Minnesota",
"MO"=>"Missouri",
"MS"=>"Mississippi",
"MT"=>"Montana",
"NC"=>"North Carolina",
"ND"=>"North Dakota",
"NE"=>"Nebraska",
"NH"=>"New Hampshire",
"NJ"=>"New Jersey",
"NM"=>"New Mexico",
"NV"=>"Nevada",
"NY"=>"New York",
"OH"=>"Ohio",
"OK"=>"Oklahoma",
"OR"=>"Oregon",
"PA"=>"Pennsylvania",
"PR"=>"Puerto Rico",
"RI"=>"Rhode Island",
"SC"=>"South Carolina",
"SD"=>"South Dakota",
"TN"=>"Tennessee",
"TX"=>"Texas",
"UT"=>"Utah",
"VA"=>"Virginia",
"VI"=>"Virgin Islands",
"VT"=>"Vermont",
"WA"=>"Washington",
"WI"=>"Wisconsin",
"WV"=>"West Virginia",
"WY"=>"Wyoming"
}
def state_code
STATES.invert[state]
end
def state_code=(value)
self.state = STATES[value]
end
def summary
to_h.values.map(&:to_s).reject(&:empty?).join(', ')
end
end
# AddressForm Glimmer Web Component (View component)
#
# Including Glimmer::Web::Component makes this class a View component and automatically
# generates a new Glimmer HTML DSL keyword that matches the lowercase underscored version
# of the name of the class. AddressForm generates address_form keyword, which can be used
# elsewhere in Glimmer HTML DSL code as done inside AddressPage below.
class AddressForm
include Glimmer::Web::Component
option :address
# Optionally, you can execute code before rendering markup.
# This is useful for pre-setup of variables (e.g. Models) that you would use in the markup.
#
# before_render do
# end
# Optionally, you can execute code after rendering markup.
# This is useful for post-setup of extra Model listeners that would interact with the
# markup elements and expect them to be rendered already.
#
# after_render do
# end
# markup block provides the content of the
markup {
div {
div(style: 'display: grid; grid-auto-columns: 80px 260px;') { |address_div|
label('Full Name: ', for: 'full-name-field')
input(id: 'full-name-field') {
value <=> [address, :full_name]
}
@somelabel = label('Street: ', for: 'street-field')
input(id: 'street-field') {
value <=> [address, :street]
}
label('Street 2: ', for: 'street2-field')
textarea(id: 'street2-field') {
value <=> [address, :street2]
}
label('City: ', for: 'city-field')
input(id: 'city-field') {
value <=> [address, :city]
}
label('State: ', for: 'state-field')
select(id: 'state-field') {
Address::STATES.each do |state_code, state|
option(value: state_code) { state }
end
value <=> [address, :state_code]
}
label('Zip Code: ', for: 'zip-code-field')
input(id: 'zip-code-field', type: 'number', min: '0', max: '99999') {
value <=> [address, :zip_code,
on_write: :to_s,
]
}
style {
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
div(style: 'margin: 5px') {
inner_text <= [address, :summary,
computed_by: address.members + ['state_code'],
]
}
}
}
end
# AddressPage Glimmer Web Component (View component)
#
# This View component represents the main page being rendered,
# as done by its `render` class method below
class AddressPage
include Glimmer::Web::Component
before_render do
@shipping_address = Address.new(
full_name: 'Johnny Doe',
street: '3922 Park Ave',
street2: 'PO BOX 8382',
city: 'San Diego',
state: 'California',
zip_code: '91913',
)
@billing_address = Address.new(
full_name: 'John C Doe',
street: '123 Main St',
street2: 'Apartment 3C',
city: 'San Diego',
state: 'California',
zip_code: '91911',
)
end
markup {
div {
h1('Shipping Address')
address_form(address: @shipping_address)
h1('Billing Address')
address_form(address: @billing_address)
}
}
end
Document.ready? do
# renders a top-level (root) AddressPage component
AddressPage.render
endScreenshot:
Hello, glimmer_component Rails Helper!
You may insert a Glimmer component anywhere into a Rails View using
glimmer_component(component_path, *args) Rails helper. Add include GlimmerHelper to ApplicationHelper
or another Rails helper, and use <%= glimmer_component("path/to/component", *args) %> in Views.
Rails ApplicationHelper setup code:
require 'glimmer/helpers/glimmer_helper'
module ApplicationHelper
# ...
include GlimmerHelper
# ...
endRails View code:
<div id="address-container">
<h1>Shipping Address </h1>
<legend>Please enter your shipping address information (Zip Code must be a valid 5 digit number)</legend>
<!-- This sample demonstrates use of glimmer_component helper with arguments -->
<%= glimmer_component('address_form',
full_name: params[:full_name],
street: params[:street],
street2: params[:street2],
city: params[:city],
state: params[:state],
zip_code: params[:zip_code]
)
%>
<div>
<a href="/"><< Back Home</a>
</div>
</div>Glimmer HTML DSL Ruby code in the frontend (app/assets/opal/address_form.rb):
require 'glimmer-dsl-web'
class AddressForm
Address = Struct.new(:full_name, :street, :street2, :city, :state, :zip_code, keyword_init: true) do
def state_code
STATES.invert[state]
end
def state_code=(value)
self.state = STATES[value]
end
def summary
to_h.values.map(&:to_s).reject(&:empty?).join(', ')
end
end
STATES = {
"AK"=>"Alaska",
"AL"=>"Alabama",
"AR"=>"Arkansas",
"AS"=>"American Samoa",
"AZ"=>"Arizona",
"CA"=>"California",
"CO"=>"Colorado",
"CT"=>"Connecticut",
"DC"=>"District of Columbia",
"DE"=>"Delaware",
"FL"=>"Florida",
"GA"=>"Georgia",
"GU"=>"Guam",
"HI"=>"Hawaii",
"IA"=>"Iowa",
"ID"=>"Idaho",
"IL"=>"Illinois",
"IN"=>"Indiana",
"KS"=>"Kansas",
"KY"=>"Kentucky",
"LA"=>"Louisiana",
"MA"=>"Massachusetts",
"MD"=>"Maryland",
"ME"=>"Maine",
"MI"=>"Michigan",
"MN"=>"Minnesota",
"MO"=>"Missouri",
"MS"=>"Mississippi",
"MT"=>"Montana",
"NC"=>"North Carolina",
"ND"=>"North Dakota",
"NE"=>"Nebraska",
"NH"=>"New Hampshire",
"NJ"=>"New Jersey",
"NM"=>"New Mexico",
"NV"=>"Nevada",
"NY"=>"New York",
"OH"=>"Ohio",
"OK"=>"Oklahoma",
"OR"=>"Oregon",
"PA"=>"Pennsylvania",
"PR"=>"Puerto Rico",
"RI"=>"Rhode Island",
"SC"=>"South Carolina",
"SD"=>"South Dakota",
"TN"=>"Tennessee",
"TX"=>"Texas",
"UT"=>"Utah",
"VA"=>"Virginia",
"VI"=>"Virgin Islands",
"VT"=>"Vermont",
"WA"=>"Washington",
"WI"=>"Wisconsin",
"WV"=>"West Virginia",
"WY"=>"Wyoming"
}
include Glimmer::Web::Component
option :full_name
option :street
option :street2
option :city
option :state
option :zip_code
attr_reader :address
before_render do
@address = Address.new(
full_name: full_name,
street: street,
street2: street2,
city: city,
state: state,
zip_code: zip_code,
)
end
markup {
div {
div(style: 'display: grid; grid-auto-columns: 80px 260px;') { |address_div|
label('Full Name: ', for: 'full-name-field')
input(id: 'full-name-field') {
value <=> [address, :full_name]
}
@somelabel = label('Street: ', for: 'street-field')
input(id: 'street-field') {
value <=> [address, :street]
}
label('Street 2: ', for: 'street2-field')
textarea(id: 'street2-field') {
value <=> [address, :street2]
}
label('City: ', for: 'city-field')
input(id: 'city-field') {
value <=> [address, :city]
}
label('State: ', for: 'state-field')
select(id: 'state-field') {
STATES.each do |state_code, state|
option(value: state_code) { state }
end
value <=> [address, :state_code]
}
label('Zip Code: ', for: 'zip-code-field')
input(id: 'zip-code-field', type: 'number', min: '0', max: '99999') {
value <=> [address, :zip_code,
on_write: :to_s,
]
}
style {
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
div(style: 'margin: 5px') {
inner_text <= [address, :summary,
computed_by: address.members + ['state_code'],
]
}
}
}
endScreenshot:
Hello, Paragraph!
To facilitate building formatted textual paragraphs in Ruby, thanks to Glimmer, the most advanced DSL engine in Ruby, the Glimmer HTML DSL is advanced enough to intelligently behave differently under different situations, like when using HTML formatting elements: <br>, <strong>, <em>, <br>, <i>, <sub>, <sup>, <del>, <ins>, <small>, <mark>
Instead of returning Ruby objects that are nested as children within their parent, the Glimmer HTML DSL returns String objects directly that can be concatenated to or embedded within other String objects via interpolation.
This enables writing code like:
p {"#{strong('Yesterday, ')}Robert suggested adding a new #{em('feature')} to our software product.#{br}}
That is close to how it is written in HTML, albeit briefer in Ruby:
<p><strong>Yesterday, </strong>Robert suggested adding a new <em>feature</em> to our software product.<br></p>
Formatting elements just like regular elements can accept text content as their first argument or as their block return value. So, the code above could equally be written as follows:
p {"#{strong{'Yesterday, '}}Robert suggested adding a new #{em{'feature'}} to our software product.#{br}}
This enables seggregating formatting element attributes if desired, as in this example:
p {"#{strong(class: 'very-string'){'Yesterday, '}}Robert suggested adding a new #{em(class: 'very-emphasized'){'feature'}} to our software product.#{br}}
Another way of writing the same code is to pass the text content as the first argument, before attributes:
p {"#{strong('Yesterday, ', class: 'very-string')}Robert suggested adding a new #{em('feature', class: 'very-emphasized')} to our software product.#{br}}
One last bit of info to keep in mind is that <span> generally generates a normal element, except when used inside a <p>'s content block, in which case it is assumed to be used for formatting, so
it returns a String to enable code like this:
p {"#{span('Yesterday, ', style: 'text-decoration: underline;')}Robert suggested adding a new #{em('feature', class: 'very-emphasized')} to our software product.#{br}}
In any case, below is a full example leveraging the Glimmer HTML DSL alternative approach when utilizing formatting elements underneath a paragraph.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
class HelloParagraph
include Glimmer::Web::Component
markup {
div {
h1(class: 'title') {
'Flying Cars Become 100% Safe with AI Powered Balance!'
}
p(class: 'intro') {"
In the early 2030's, #{em('flying cars')} became affordable after their prices dropped
below #{small(del('$100,000'))}#{ins('$80,000')} as a result of the innovations of #{strong('Travel-X')}. Still, that did not
make #{em('flying cars')} any popular due to the extreme difficulty in piloting such flying vehicles for the average
person, making it very tough to pass the tests for getting a piloting license given the learning curve.
"}
p {"
That said, #{b('Travel-X')} has recently come up with a new feature for their flagship #{i('flying car')},
the Ptero#{sub(1)}#{sup('TM')}, which relies on AI#{sub(2)} to automatically balance the flying cars in mid-air,
thus significantly facilitating their piloting by the average consumer.
"}
p(class: 'conclusion') {"
That Ptero#{sup('TM')} will be so stable and well balanced while flying that the consumer will be able to drive
as if it is a plain old car, with the only difference being vertical elevation, the control of which will be handled
automatically by AI. The Ptero#{sup('TM')} will debut for #{span(style: 'text-decoration: underline dashed;'){'$79,000'}}.
"}
h2(class: 'legend-title') {
mark('Legend:')
}
p(class: 'legend') {"
#{strong("1- Ptero:")} Pterosaur is flying dinosaur species#{br}
#{strong("2- AI:")} Artificial Intelligence#{br}
"}
}
}
end
Document.ready? do
HelloParagraph.render
endScreenshot:
--
Hello, Observer!
Glimmer DSL for Web provides the observe(model, attribute) { ... } keyword to employ the Observer Design Pattern as per MVC (Model View Controller), enabling Views to observe Models and update themselves in response to changes. If the observe keyword is used from inside a Component, when the Component is removed or its top-level element is removed, the observer is automatically cleaned up. The need for such explicit observers is significantly diminished by the availablility of the more advanced Unidirectional Data-Binding Support and Bidirectional Data-Binding Support.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
class NumberHolder
attr_accessor :number
def initialize
self.number = 50
end
end
class HelloObserver
include Glimmer::Web::Component
before_render do
@number_holder = NumberHolder.new
end
after_render do
@number_input.value = @number_holder.number
@range_input.value = @number_holder.number
# Observe Model attribute @number_holder.number for changes and update View
# Observer is automatically cleaned up if remove method is called on rendered HelloObserver
# or its top-level element
observe(@number_holder, :number) do
number_string = @number_holder.number.to_s
@number_input.value = number_string unless @number_input.value == number_string
@range_input.value = number_string unless @range_input.value == number_string
end
# Bidirectional Data-Binding does the same thing automatically
# Just disable the observe block above as well as the oninput listeners below
# and enable the `value <=> [@number_holder, :number]` lines to try the data-binding version
# Learn more about Bidirectional and Unidirectional Data-Binding in hello_data_binding.rb
end
markup {
div {
div {
@number_input = input(type: 'number', min: 0, max: 100) {
# oninput listener updates Model attribute @number_holder.number
oninput do
@number_holder.number = @number_input.value.to_i
end
# Bidirectional Data-Binding simplifies the implementation significantly
# by enabling the following line and disabling oninput listeners as well
# as the after_body observe block observer
# Learn more about Bidirectional and Unidirectional Data-Binding in hello_data_binding.rb
# value <=> [@number_holder, :number]
}
}
div {
@range_input = input(type: 'range', min: 0, max: 100) {
# oninput listener updates Model attribute @number_holder.number
oninput do
@number_holder.number = @range_input.value.to_i
end
# Bidirectional Data-Binding simplifies the implementation significantly
# by enabling the following line and disabling oninput listeners as well
# as the after_body observe block observer
# Learn more about Bidirectional and Unidirectional Data-Binding in hello_data_binding.rb
# value <=> [@number_holder, :number]
}
}
}
}
end
Document.ready? do
HelloObserver.render
endScreenshot:
To get started, Setup Ruby gem, read Usage instructions, and check out more Samples (including playing around with a Rails sample app).
--
NOTE: Glimmer DSL for Web is a Beta project. If you want it developed faster, please open an issue report. I have completed some GitHub project features much faster before due to issue reports and pull requests. Please help make better by contributing, adopting for small or low risk projects, and providing feedback. It is still a Beta, so the more feedback and issues you report the better.
Learn more about the differences between various Glimmer DSLs by looking at:
- Glimmer DSL for Web
Glimmer DSL for Web will begin by supporting Opal Ruby on Rails. Opal is a lightweight Ruby to JavaScript transpiler that results in small downloadables compared to WASM. In the future, the project might grow to support Ruby WASM as an alternative to Opal Ruby that could be switched to with a simple configuration change.
- Ruby 3.0+
- Rails 7: https://github.com/rails/rails
You can setup Glimmer DSL for Web in Rails 7, Rails 6, or Standalone (No Rails).
(NOTE: Keep in mind this is a Beta. If you run into issues, try to go back to a previous revision. Also, there is a slight chance any issues you encounter are fixed in master or some other branch that you could check out instead)
Please follow these steps to setup.
Install a Rails 7 gem:
gem install rails -v7.0.1
Start a new Rails 7 app:
rails new glimmer_app_server
Add the following to Gemfile:
gem 'glimmer-dsl-web', '~> 0.2.4'
Run:
bundle
(run rm -rf tmp/cache from inside your Rails app if you upgrade your glimmer-dsl-web gem version from an older one to clear Opal-Rails's cache)
Follow opal-rails instructions, basically running:
bin/rails g opal:install
To enable the glimmer-dsl-web gem in the frontend, edit config/initializers/assets.rb and add the following at the bottom:
Opal.use_gem 'glimmer-dsl-web'
Opal.append_path Rails.root.join('app', 'assets', 'opal')To enable Opal Browser Debugging in Ruby with the Source Maps feature, edit config/initializers/opal.rb and add the following inside the Rails.application.configure do; end block at the bottom of it:
config.assets.debug = true if Rails.env.development?Assuming this is a brand new Rails application and you do not have any Rails resources, you can scaffold the welcome resource just for testing purposes.
Run:
rails g scaffold welcome
Run:
rails db:migrate
Add the following to config/routes.rb inside the Rails.application.routes.draw block:
root to: 'welcomes#index'Clear the file app/views/welcomes/index.html.erb completely from all content.
Rename app/assets/javascript/application.js.rb file to app/assets/javascript/opal_application.rb.
Rename app/assets/javascript directory to app/assets/opal.
Edit app/assets/config/manifest.js and update //= link_directory ../javascript .js to //= link_directory ../opal .js:
//= link_directory ../opal .jsEdit app/views/layouts/application.html.erb and update <%= javascript_include_tag "application", "data-turbolinks-track": "reload" %> to <%= javascript_include_tag "opal_application", "data-turbolinks-track": "reload" %>:
<%= javascript_include_tag "opal_application", "data-turbolinks-track": "reload" %>Edit and replace app/assets/opal/opal_application.rb content with code below (optionally including a require statement for one of the samples below):
require 'glimmer-dsl-web' # brings opal and other dependencies automatically
# Add more require-statements or Glimmer HTML DSL coderequire 'glimmer-dsl-web'
require 'glimmer-dsl-web/samples/hello/hello_world.rb'If the <body></body> element (where the Glimmer HTML DSL adds elements by default) is not available when the JS file is loading, you need to put the code inside a Document.ready? do; end (but, it is recommended that you load the JS file after the parent element like <body></body> is in the page already for faster performance, which is guaranteed automatically by using glimmer_component, mentioned in details below):
require 'glimmer-dsl-web'
Document.ready? do
require 'glimmer-dsl-web/samples/hello/hello_world.rb'
endExample to confirm setup is working:
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
# This will hook into element #app-container and then build HTML inside it using Ruby DSL code
div {
label(class: 'greeting') {
'Hello, World!'
}
}
endThat produces:
<body>
<div data-parent="body" class="element element-1">
<label class="greeting element element-2">
Hello, World!
</label>
</div>
</body>Start the Rails server:
rails s
Visit http://localhost:3000
You should see:
If you want to customize where the top-level element is mounted, just pass a parent: 'css_selector' option.
HTML:
...
<div id="app-container">
</div>
...Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
# This will hook into element #app-container and then build HTML inside it using Ruby DSL code
div(parent: '#app-container') {
label(class: 'greeting') {
'Hello, World!'
}
}
endThat produces:
...
<div id="app-container">
<div data-parent="app-container" class="element element-1">
<label class="greeting element element-2">
Hello, World!
</label>
</div>
</div>
...You may insert a Glimmer component anywhere into a Rails View using glimmer_component(component_path, *args) Rails helper. Add include GlimmerHelper to ApplicationHelper or another Rails helper, and use <%= glimmer_component("path/to/component", *args) %> in Views.
To use glimmer_component, edit app/helpers/application_helper.rb in your Rails application, add require 'glimmer/helpers/glimmer_helper' on top and include GlimmerHelper inside module.
app/helpers/application_helper.rb should look like this after the change:
require 'glimmer/helpers/glimmer_helper'
module ApplicationHelper
# ...
include GlimmerHelper
# ...
endNote that Turbo is disabled on Glimmer elements/components. You can still use Turbo/Hotwire side by side with Glimmer DSL for Web by using one of the two technologies in every page. But, mixing them in the same pages is not recommended at the moment, so any pages loaded with Glimmer DSL for Web must be loaded without Turbo (e.g. by putting "data-turbo"="false" on anchor "a" tag links to Glimmer pages).
If you run into any issues in setup, refer to the Sample Glimmer DSL for Web Rails 7 App project (in case I forgot to include some setup steps by mistake).
Otherwise, if you still cannot setup successfully (even with the help of the sample project, or if the sample project stops working), please do not hesitate to report an Issue request or fix and submit a Pull Request.
Next, read Usage instructions, and check out Samples.
Please follow these steps to setup.
Install a Rails 6 gem:
gem install rails -v6.1.4.6
Start a new Rails 6 app (skipping webpack):
rails new glimmer_app_server --skip-webpack-install
Disable the webpacker gem line in Gemfile:
# gem 'webpacker', '~> 5.0'Add the following to Gemfile:
gem 'glimmer-dsl-web', '~> 0.2.4'Run:
bundle
(run rm -rf tmp/cache from inside your Rails app if you upgrade your glimmer-dsl-web gem version from an older one to clear Opal-Rails's cache)
Follow opal-rails instructions, basically running:
bin/rails g opal:install
To enable the glimmer-dsl-web gem in the frontend, edit config/initializers/assets.rb and add the following at the bottom:
Opal.use_gem 'glimmer-dsl-web'
Opal.append_path Rails.root.join('app', 'assets', 'opal')To enable Opal Browser Debugging in Ruby with the Source Maps feature, edit config/initializers/opal.rb and add the following inside the Rails.application.configure do; end block at the bottom of it:
config.assets.debug = true if Rails.env.development?Assuming this is a brand new Rails application and you do not have any Rails resources, you can scaffold the welcome resource just for testing purposes.
Run:
rails g scaffold welcome
Run:
rails db:migrate
Add the following to config/routes.rb inside the Rails.application.routes.draw block:
root to: 'welcomes#index'Also, delete the following line:
<%= javascript_pack_tag 'application', 'data-turbolinks-track': 'reload' %>Clear the file app/views/welcomes/index.html.erb completely from all content.
Rename app/assets/javascript/application.js.rb file to app/assets/javascript/opal_application.rb.
Rename app/assets/javascript directory to app/assets/opal.
Edit app/assets/config/manifest.js and update //= link_directory ../javascript .js to //= link_directory ../opal .js:
//= link_directory ../opal .jsEdit app/views/layouts/application.html.erb and update <%= javascript_include_tag "application", "data-turbolinks-track": "reload" %> to <%= javascript_include_tag "opal_application", "data-turbolinks-track": "reload" %>:
<%= javascript_include_tag "opal_application", "data-turbolinks-track": "reload" %>Edit and replace app/assets/opal/opal_application.rb content with code below (optionally including a require statement for one of the samples below):
require 'glimmer-dsl-web' # brings opal and other dependencies automatically
# Add more require-statements or Glimmer HTML DSL codeExample to confirm setup is working:
Initial HTML Markup:
...
<div id="app-container">
</div>
...Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
# This will hook into element #app-container and then build HTML inside it using Ruby DSL code
div(parent: '#app-container') {
label(class: 'greeting') {
'Hello, World!'
}
}
endThat produces:
...
<div id="app-container">
<div data-parent="#app-container" class="element element-1">
<label class="greeting element element-2">
Hello, World!
</label>
</div>
</div>
...Start the Rails server:
rails s
Visit http://localhost:3000
You should see:
You may insert a Glimmer component anywhere into a Rails View using glimmer_component(component_path, *args) Rails helper. Add include GlimmerHelper to ApplicationHelper or another Rails helper, and use <%= glimmer_component("path/to/component", *args) %> in Views.
To use glimmer_component, edit app/helpers/application_helper.rb in your Rails application, add require 'glimmer/helpers/glimmer_helper' on top and include GlimmerHelper inside module.
app/helpers/application_helper.rb should look like this after the change:
require 'glimmer/helpers/glimmer_helper'
module ApplicationHelper
# ...
include GlimmerHelper
# ...
endNote that Turbo is disabled on Glimmer elements/components. You can still use Turbo/Hotwire side by side with Glimmer DSL for Web by using one of the two technologies in every page. But, mixing them in the same pages is not recommended at the moment, so any pages loaded with Glimmer DSL for Web must be loaded without Turbo (e.g. by putting "data-turbo"="false" on anchor "a" tag links to Glimmer pages).
NOT RELEASED OR SUPPORTED YET
If you run into any issues in setup, refer to the Sample Glimmer DSL for Web Rails 6 App project (in case I forgot to include some setup steps by mistake).
Otherwise, if you still cannot setup successfully (even with the help of the sample project, or if the sample project stops working), please do not hesitate to report an Issue request or fix and submit a Pull Request.
Next, read Usage instructions, and check out Samples.
Andreas Idogawa-Wildi (@Largo) created a project that demonstrates how to use Glimmer DSL for Web standalone (without Rails):
https://github.com/Largo/glimmer-dsl-web-standalone-demo
Glimmer DSL for Web offers a HTML DSL (Graphical User Interface Domain Specific Language) for building HTML Web User Interfaces declaratively in Ruby.
1- Keywords (HTML Elements)
You can declare any HTML element by simply using the lowercase version of its name (Ruby convention for method names) like div, span, form, input, button, table, tr, th, and td.
Under the hood, HTML element DSL keywords are invoked as Ruby methods.
2- Arguments (HTML Attributes + Text Content)
You can set any HTML element attributes by passing as keyword arguments to element methods like div(id: 'container', class: 'stack') or input(type: 'email', required: true)
Also, if the element has a little bit of text content that can fit in one line, it can be passed as the 1st argument like label('Name: ', for: 'name_field'), button('Calculate', class: 'round-button'), or span('Mr')
3- Content Block (Properties + Listeners + Nested Elements + Text Content)
Element methods can accept a Ruby content block. It intentionally has a {...} style even as a multi-line block to indicate that the code is declarative HTML DSL structure code (intentionally breaking away from Ruby imperative code conventions given this is a declarative HTML DSL (Domain Specific Language), meaning a different language that has its own conventions, embedded within Ruby).
You can nest HTML element properties under an element like:
input(type: 'text') {
content_editable false
}You can nest HTML event listeners under an element by using the HTML event listener name (e.g. onclick, onchange, onblur):
button('Add') {
onclick do
@model.add_selected_element
end
}Given that listener code is imperative, it uses a do; end style for Ruby blocks to separate it from declarative HTML DSL structure code and enable quicker readability of the code.
You can nest other HTML elements under an HTML element the same way you do so in HTML, like:
form {
div(class: 'field-row') {
label('Name: ', for: 'name-field')
input(id: 'name-field', class: 'field', type: 'text', required: true)
}
div(class: 'field-row') {
label('Email: ', for: 'email-field')
input(id: 'email-field', class: 'field', type: 'email', required: true)
}
button('Add Contact', class: 'submit-button') {
onclick do
...
end
}
}You can nest text content underneath an element's Ruby block provided it is the return value of the block (last declared value), like:
p(class: 'summary') {
'This text content is going into the body of the span element'
}4- Operations (Properties + Functions)
You can get/set any element property or invoke any element function by simply calling the lowercase underscored version of their name in Ruby like input.check_validity, input.value, and input.id.
Next, check out Samples.
All HTML elements, following the Ruby method name standard of lowercase and underscored names.
All HTML attributes, following the Ruby method name standard of lowercase and underscored names.
All HTML events, same event attribute names as in HTML.
This project is inspired by Glimmer DSL for Opal and is similar in enabling Web Frontend development with Ruby. Glimmer DSL for Web mainly differs from Glimmer DSL for Opal by adopting a DSL that follows web-like HTML syntax in Ruby to facilitate leveraging existing HTML/CSS/JS skills instead of adopting a desktop HTML DSL that is webified. As a result, applications written in Glimmer DSL for Opal are not compatible with Glimmer DSL for Web.
This external Sample Selector app is built using Rails and Glimmer DSL for Web, including all the samples mentioned below configured inside a Rails Opal web app with all the prerequisites ready to go for convenience (there is a very minimal Standalone [No Rails] static site sample app too):
https://github.com/AndyObtiva/sample-glimmer-dsl-web-rails7-app
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
div {
'Hello, World!'
}
endThat produces the following under <body></body>:
<div data-parent="body" class="element element-1">
Hello, World!
</div>
Alternative syntax (useful when an element has text content that fits in one line):
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
div('Hello, World!')
endThat produces the following under <body></body>:
<div data-parent="body" class="element element-1">
Hello, World!
</div>
You can also mount the div elsewhere by passing the parent: parent_css_selector option (e.g. div(parent: 'div#app-container') { 'Hello, World!' }).
Event listeners can be setup on any element using the same event names used in HTML (e.g. onclick) while passing in a standard Ruby block to handle behavior. $$ gives access to JS global scope from Ruby to invoke functions like alert.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
div {
button('Greet') {
onclick do
$$.alert('Hello, Button!')
end
}
}
endThat produces the following under <body></body>:
<div data-parent="body" class="element element-1">
<button class="element element-2">Greet</button>
</div>Screenshot:
Glimmer DSL for Web gives access to all Web Browser built-in features like HTML form validations, input focus, events, and element functions from a very terse and productive Ruby HTML DSL. Also, you can apply CSS styles by including directly in Ruby code as a string, using Glimmer DSL for CSS, or managing CSS completely separately using something like SCSS. The CSS techniques could be combined as well, like by managing common reusable CSS styles separately in SCSS, but adding component specific CSS styles in Ruby when it is more convenient.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
include Glimmer
Document.ready? do
div {
h1('Contact Form')
form {
div {
label('Name: ', for: 'name-field')
@name_input = input(type: 'text', id: 'name-field', required: true, autofocus: true)
}
div {
label('Email: ', for: 'email-field')
@email_input = input(type: 'email', id: 'email-field', required: true)
}
div {
input(type: 'submit', value: 'Add Contact') {
onclick do |event|
if ([@name_input, @email_input].all? {|input| input.check_validity })
# re-open table content and add row
@table.content {
tr {
td { @name_input.value }
td { @email_input.value }
}
}
@email_input.value = @name_input.value = ''
@name_input.focus
end
end
}
}
}
h1('Contacts Table')
@table = table {
tr {
th('Name')
th('Email')
}
tr {
td('John Doe')
td('johndoe@example.com')
}
tr {
td('Jane Doe')
td('janedoe@example.com')
}
}
# CSS Styles
style {
# CSS can be included as a String as done below, or as Glimmer DSL for CSS syntax (Ruby code) as done in other samples
<<~CSS
input {
margin: 5px;
}
input[type=submit] {
margin: 5px 0;
}
table {
border:1px solid grey;
border-spacing: 0;
}
table tr td, table tr th {
padding: 5px;
}
table tr:nth-child(even) {
background: #ccc;
}
CSS
}
}
endThat produces the following under <body></body>:
<div data-parent="body" class="element element-1">
<h1 class="element element-2">Contact Form</h1>
<form class="element element-3">
<div class="element element-4">
<label for="name-field" class="element element-5">Name: </label>
<input type="text" id="name-field" required="true" autofocus="true" class="element element-6">
</div>
<div class="element element-7">
<label for="email-field" class="element element-8">Email: </label>
<input type="email" id="email-field" required="true" class="element element-9">
</div>
<div class="element element-10">
<input type="submit" value="Add Contact" class="element element-11">
</div>
</form>
<h1 class="element element-12">Contacts Table</h1>
<table class="element element-13">
<tr class="element element-14">
<th class="element element-15">Name</th>
<th class="element element-16">Email</th>
</tr>
<tr class="element element-17">
<td class="element element-18">John Doe</td>
<td class="element element-19">johndoe@example.com</td>
</tr>
<tr class="element element-20">
<td class="element element-21">Jane Doe</td>
<td class="element element-22">janedoe@example.com</td>
</tr>
</table>
<style class="element element-23">
input {
margin: 5px;
}
input[type=submit] {
margin: 5px 0;
}
table {
border:1px solid grey;
border-spacing: 0;
}
table tr td, table tr th {
padding: 5px;
}
table tr:nth-child(even) {
background: #ccc;
}
</style>
</div>Screenshot:
Glimmer DSL for Web provides the observe(model, attribute) { ... } keyword to employ the Observer Design Pattern as per MVC (Model View Controller), enabling Views to observe Models and update themselves in response to changes. If the observe keyword is used from inside a Component, when the Component is removed or its top-level element is removed, the observer is automatically cleaned up. The need for such explicit observers is significantly diminished by the availablility of the more advanced Unidirectional Data-Binding Support and Bidirectional Data-Binding Support.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
class NumberHolder
attr_accessor :number
def initialize
self.number = 50
end
end
class HelloObserver
include Glimmer::Web::Component
before_render do
@number_holder = NumberHolder.new
end
after_render do
@number_input.value = @number_holder.number
@range_input.value = @number_holder.number
# Observe Model attribute @number_holder.number for changes and update View
# Observer is automatically cleaned up if remove method is called on rendered HelloObserver
# or its top-level element
observe(@number_holder, :number) do
number_string = @number_holder.number.to_s
@number_input.value = number_string unless @number_input.value == number_string
@range_input.value = number_string unless @range_input.value == number_string
end
# Bidirectional Data-Binding does the same thing automatically
# Just disable the observe block above as well as the oninput listeners below
# and enable the `value <=> [@number_holder, :number]` lines to try the data-binding version
# Learn more about Bidirectional and Unidirectional Data-Binding in hello_data_binding.rb
end
markup {
div {
div {
@number_input = input(type: 'number', min: 0, max: 100) {
# oninput listener updates Model attribute @number_holder.number
oninput do
@number_holder.number = @number_input.value.to_i
end
# Bidirectional Data-Binding simplifies the implementation significantly
# by enabling the following line and disabling oninput listeners as well
# as the after_body observe block observer
# Learn more about Bidirectional and Unidirectional Data-Binding in hello_data_binding.rb
# value <=> [@number_holder, :number]
}
}
div {
@range_input = input(type: 'range', min: 0, max: 100) {
# oninput listener updates Model attribute @number_holder.number
oninput do
@number_holder.number = @range_input.value.to_i
end
# Bidirectional Data-Binding simplifies the implementation significantly
# by enabling the following line and disabling oninput listeners as well
# as the after_body observe block observer
# Learn more about Bidirectional and Unidirectional Data-Binding in hello_data_binding.rb
# value <=> [@number_holder, :number]
}
}
}
}
end
Document.ready? do
HelloObserver.render
endScreenshot:
Glimmer DSL for Web intuitively supports both Unidirectional (One-Way) Data-Binding via the <= operator and Bidirectional (Two-Way) Data-Binding via the <=> operator, incredibly simplifying how to sync View properties with Model attributes with the simplest code to reason about.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
Address = Struct.new(:street, :street2, :city, :state, :zip_code, keyword_init: true) do
STATES = {
"AK"=>"Alaska",
"AL"=>"Alabama",
"AR"=>"Arkansas",
"AS"=>"American Samoa",
"AZ"=>"Arizona",
"CA"=>"California",
"CO"=>"Colorado",
"CT"=>"Connecticut",
"DC"=>"District of Columbia",
"DE"=>"Delaware",
"FL"=>"Florida",
"GA"=>"Georgia",
"GU"=>"Guam",
"HI"=>"Hawaii",
"IA"=>"Iowa",
"ID"=>"Idaho",
"IL"=>"Illinois",
"IN"=>"Indiana",
"KS"=>"Kansas",
"KY"=>"Kentucky",
"LA"=>"Louisiana",
"MA"=>"Massachusetts",
"MD"=>"Maryland",
"ME"=>"Maine",
"MI"=>"Michigan",
"MN"=>"Minnesota",
"MO"=>"Missouri",
"MS"=>"Mississippi",
"MT"=>"Montana",
"NC"=>"North Carolina",
"ND"=>"North Dakota",
"NE"=>"Nebraska",
"NH"=>"New Hampshire",
"NJ"=>"New Jersey",
"NM"=>"New Mexico",
"NV"=>"Nevada",
"NY"=>"New York",
"OH"=>"Ohio",
"OK"=>"Oklahoma",
"OR"=>"Oregon",
"PA"=>"Pennsylvania",
"PR"=>"Puerto Rico",
"RI"=>"Rhode Island",
"SC"=>"South Carolina",
"SD"=>"South Dakota",
"TN"=>"Tennessee",
"TX"=>"Texas",
"UT"=>"Utah",
"VA"=>"Virginia",
"VI"=>"Virgin Islands",
"VT"=>"Vermont",
"WA"=>"Washington",
"WI"=>"Wisconsin",
"WV"=>"West Virginia",
"WY"=>"Wyoming"
}
def state_code
STATES.invert[state]
end
def state_code=(value)
self.state = STATES[value]
end
def summary
string_attributes = to_h.except(:billing_and_shipping)
summary = string_attributes.values.map(&:to_s).reject(&:empty?).join(', ')
summary += " (Billing & Shipping)" if billing_and_shipping
summary
end
end
@address = Address.new(
street: '123 Main St',
street2: 'Apartment 3C, 2nd door to the right',
city: 'San Diego',
state: 'California',
zip_code: '91911',
billing_and_shipping: true,
)
include Glimmer
Document.ready? do
div {
div(style: 'display: grid; grid-auto-columns: 80px 260px;') { |address_div|
label('Street: ', for: 'street-field')
input(id: 'street-field') {
# Bidirectional Data-Binding with <=> ensures input.value and @address.street
# automatically stay in sync when either side changes
value <=> [@address, :street]
}
label('Street 2: ', for: 'street2-field')
textarea(id: 'street2-field') {
value <=> [@address, :street2]
}
label('City: ', for: 'city-field')
input(id: 'city-field') {
value <=> [@address, :city]
}
label('State: ', for: 'state-field')
select(id: 'state-field') {
Address::STATES.each do |state_code, state|
option(value: state_code) { state }
end
value <=> [@address, :state_code]
}
label('Zip Code: ', for: 'zip-code-field')
input(id: 'zip-code-field', type: 'number', min: '0', max: '99999') {
# Bidirectional Data-Binding with <=> ensures input.value and @address.zip_code
# automatically stay in sync when either side changes
# on_write option specifies :to_s method to invoke on value before writing to model attribute
# to ensure the numeric zip code value is stored as a String
value <=> [@address, :zip_code,
on_write: :to_s,
]
}
div(style: 'grid-column: 1 / span 2') {
input(id: 'billing-and-shipping-field', type: 'checkbox') {
checked <=> [@address, :billing_and_shipping]
}
label(for: 'billing-and-shipping-field') {
'Use this address for both Billing & Shipping'
}
}
style {
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
div(style: 'margin: 5px') {
# Unidirectional Data-Binding is done with <= to ensure @address.summary changes
# automatically update div.inner_text
# (computed by changes to address attributes, meaning if street changes,
# @address.summary is automatically recomputed.)
inner_text <= [@address, :summary,
computed_by: @address.members + ['state_code'],
]
}
}
endScreenshot:
If you need to regenerate HTML element content dynamically, you can use Content Data-Binding to effortlessly rebuild HTML elements based on changes in a Model attribute that provides the source data. In this example, we generate multiple address forms based on the number of addresses the user has.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
class Address
attr_accessor :text
attr_reader :name, :street, :city, :state, :zip
def name=(value)
@name = value
update_text
end
def street=(value)
@street = value
update_text
end
def city=(value)
@city = value
update_text
end
def state=(value)
@state = value
update_text
end
def zip=(value)
@zip = value
update_text
end
private
def update_text
self.text = [name, street, city, state, zip].compact.reject(&:empty?).join(', ')
end
end
class User
attr_accessor :addresses
attr_reader :address_count
def initialize
@address_count = 1
@addresses = []
update_addresses
end
def address_count=(value)
value = [[1, value.to_i].max, 3].min
@address_count = value
update_addresses
end
private
def update_addresses
address_count_change = address_count - addresses.size
if address_count_change > 0
address_count_change.times { addresses << Address.new }
else
address_count_change.abs.times { addresses.pop }
end
end
end
@user = User.new
include Glimmer
Document.ready? do
div {
div {
label('Number of addresses: ', for: 'address-count-field')
input(id: 'address-count-field', type: 'number', min: 1, max: 3) {
value <=> [@user, :address_count]
}
}
div {
# Content Data-Binding is used to dynamically (re)generate content of div
# based on changes to @user.addresses, replacing older content on every change
content(@user, :addresses) do
@user.addresses.each do |address|
div {
div(style: 'display: grid; grid-auto-columns: 80px 280px;') { |address_div|
[:name, :street, :city, :state, :zip].each do |attribute|
label(attribute.to_s.capitalize, for: "#{attribute}-field")
input(id: "#{attribute}-field", type: 'text') {
value <=> [address, attribute]
}
end
div(style: 'grid-column: 1 / span 2;') {
inner_text <= [address, :text]
}
style {
r(address_div.selector) {
margin '10px 0'
}
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} label") {
grid_column '1'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
}
end
end
}
}
endScreenshot:
You can define Glimmer web components (View components) to reuse visual concepts to your heart's content,
by simply defining a class with include Glimmer::Web::Component and encasing the reusable markup inside
a markup {...} block. Glimmer web components automatically extend the Glimmer HTML DSL with new keywords
that match the underscored versions of the component class names (e.g. an OrderSummary class yields
the order_summary keyword for reusing that component within the Glimmer HTML DSL).
You may insert a Glimmer component anywhere into a Rails View using glimmer_component(component_path, *args)
Rails helper (more about it in Hello, glimmer_component Rails Helper!).
Below, we define an AddressForm component that generates an address_form keyword, and then we
reuse it twice inside an AddressPage component displaying a Shipping Address and a Billing Address.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
Address = Struct.new(:full_name, :street, :street2, :city, :state, :zip_code, keyword_init: true) do
STATES = {
"AK"=>"Alaska",
"AL"=>"Alabama",
"AR"=>"Arkansas",
"AS"=>"American Samoa",
"AZ"=>"Arizona",
"CA"=>"California",
"CO"=>"Colorado",
"CT"=>"Connecticut",
"DC"=>"District of Columbia",
"DE"=>"Delaware",
"FL"=>"Florida",
"GA"=>"Georgia",
"GU"=>"Guam",
"HI"=>"Hawaii",
"IA"=>"Iowa",
"ID"=>"Idaho",
"IL"=>"Illinois",
"IN"=>"Indiana",
"KS"=>"Kansas",
"KY"=>"Kentucky",
"LA"=>"Louisiana",
"MA"=>"Massachusetts",
"MD"=>"Maryland",
"ME"=>"Maine",
"MI"=>"Michigan",
"MN"=>"Minnesota",
"MO"=>"Missouri",
"MS"=>"Mississippi",
"MT"=>"Montana",
"NC"=>"North Carolina",
"ND"=>"North Dakota",
"NE"=>"Nebraska",
"NH"=>"New Hampshire",
"NJ"=>"New Jersey",
"NM"=>"New Mexico",
"NV"=>"Nevada",
"NY"=>"New York",
"OH"=>"Ohio",
"OK"=>"Oklahoma",
"OR"=>"Oregon",
"PA"=>"Pennsylvania",
"PR"=>"Puerto Rico",
"RI"=>"Rhode Island",
"SC"=>"South Carolina",
"SD"=>"South Dakota",
"TN"=>"Tennessee",
"TX"=>"Texas",
"UT"=>"Utah",
"VA"=>"Virginia",
"VI"=>"Virgin Islands",
"VT"=>"Vermont",
"WA"=>"Washington",
"WI"=>"Wisconsin",
"WV"=>"West Virginia",
"WY"=>"Wyoming"
}
def state_code
STATES.invert[state]
end
def state_code=(value)
self.state = STATES[value]
end
def summary
to_h.values.map(&:to_s).reject(&:empty?).join(', ')
end
end
# AddressForm Glimmer Web Component (View component)
#
# Including Glimmer::Web::Component makes this class a View component and automatically
# generates a new Glimmer HTML DSL keyword that matches the lowercase underscored version
# of the name of the class. AddressForm generates address_form keyword, which can be used
# elsewhere in Glimmer HTML DSL code as done inside AddressPage below.
class AddressForm
include Glimmer::Web::Component
option :address
# Optionally, you can execute code before rendering markup.
# This is useful for pre-setup of variables (e.g. Models) that you would use in the markup.
#
# before_render do
# end
# Optionally, you can execute code after rendering markup.
# This is useful for post-setup of extra Model listeners that would interact with the
# markup elements and expect them to be rendered already.
#
# after_render do
# end
# markup block provides the content of the
markup {
div {
div(style: 'display: grid; grid-auto-columns: 80px 260px;') { |address_div|
label('Full Name: ', for: 'full-name-field')
input(id: 'full-name-field') {
value <=> [address, :full_name]
}
@somelabel = label('Street: ', for: 'street-field')
input(id: 'street-field') {
value <=> [address, :street]
}
label('Street 2: ', for: 'street2-field')
textarea(id: 'street2-field') {
value <=> [address, :street2]
}
label('City: ', for: 'city-field')
input(id: 'city-field') {
value <=> [address, :city]
}
label('State: ', for: 'state-field')
select(id: 'state-field') {
Address::STATES.each do |state_code, state|
option(value: state_code) { state }
end
value <=> [address, :state_code]
}
label('Zip Code: ', for: 'zip-code-field')
input(id: 'zip-code-field', type: 'number', min: '0', max: '99999') {
value <=> [address, :zip_code,
on_write: :to_s,
]
}
style {
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
div(style: 'margin: 5px') {
inner_text <= [address, :summary,
computed_by: address.members + ['state_code'],
]
}
}
}
end
# AddressPage Glimmer Web Component (View component)
#
# This View component represents the main page being rendered,
# as done by its `render` class method below
class AddressPage
include Glimmer::Web::Component
before_render do
@shipping_address = Address.new(
full_name: 'Johnny Doe',
street: '3922 Park Ave',
street2: 'PO BOX 8382',
city: 'San Diego',
state: 'California',
zip_code: '91913',
)
@billing_address = Address.new(
full_name: 'John C Doe',
street: '123 Main St',
street2: 'Apartment 3C',
city: 'San Diego',
state: 'California',
zip_code: '91911',
)
end
markup {
div {
h1('Shipping Address')
address_form(address: @shipping_address)
h1('Billing Address')
address_form(address: @billing_address)
}
}
end
Document.ready? do
# renders a top-level (root) AddressPage component
AddressPage.render
endScreenshot:
You may insert a Glimmer component anywhere into a Rails View using
glimmer_component(component_path, *args) Rails helper. Add include GlimmerHelper to ApplicationHelper
or another Rails helper, and use <%= glimmer_component("path/to/component", *args) %> in Views.
Rails ApplicationHelper setup code:
require 'glimmer/helpers/glimmer_helper'
module ApplicationHelper
# ...
include GlimmerHelper
# ...
endRails View code:
<div id="address-container">
<h1>Shipping Address </h1>
<legend>Please enter your shipping address information (Zip Code must be a valid 5 digit number)</legend>
<!-- This sample demonstrates use of glimmer_component helper with arguments -->
<%= glimmer_component('address_form',
full_name: params[:full_name],
street: params[:street],
street2: params[:street2],
city: params[:city],
state: params[:state],
zip_code: params[:zip_code]
)
%>
<div>
<a href="/"><< Back Home</a>
</div>
</div>Glimmer HTML DSL Ruby code in the frontend (app/assets/opal/address_form.rb):
require 'glimmer-dsl-web'
class AddressForm
Address = Struct.new(:full_name, :street, :street2, :city, :state, :zip_code, keyword_init: true) do
def state_code
STATES.invert[state]
end
def state_code=(value)
self.state = STATES[value]
end
def summary
to_h.values.map(&:to_s).reject(&:empty?).join(', ')
end
end
STATES = {
"AK"=>"Alaska",
"AL"=>"Alabama",
"AR"=>"Arkansas",
"AS"=>"American Samoa",
"AZ"=>"Arizona",
"CA"=>"California",
"CO"=>"Colorado",
"CT"=>"Connecticut",
"DC"=>"District of Columbia",
"DE"=>"Delaware",
"FL"=>"Florida",
"GA"=>"Georgia",
"GU"=>"Guam",
"HI"=>"Hawaii",
"IA"=>"Iowa",
"ID"=>"Idaho",
"IL"=>"Illinois",
"IN"=>"Indiana",
"KS"=>"Kansas",
"KY"=>"Kentucky",
"LA"=>"Louisiana",
"MA"=>"Massachusetts",
"MD"=>"Maryland",
"ME"=>"Maine",
"MI"=>"Michigan",
"MN"=>"Minnesota",
"MO"=>"Missouri",
"MS"=>"Mississippi",
"MT"=>"Montana",
"NC"=>"North Carolina",
"ND"=>"North Dakota",
"NE"=>"Nebraska",
"NH"=>"New Hampshire",
"NJ"=>"New Jersey",
"NM"=>"New Mexico",
"NV"=>"Nevada",
"NY"=>"New York",
"OH"=>"Ohio",
"OK"=>"Oklahoma",
"OR"=>"Oregon",
"PA"=>"Pennsylvania",
"PR"=>"Puerto Rico",
"RI"=>"Rhode Island",
"SC"=>"South Carolina",
"SD"=>"South Dakota",
"TN"=>"Tennessee",
"TX"=>"Texas",
"UT"=>"Utah",
"VA"=>"Virginia",
"VI"=>"Virgin Islands",
"VT"=>"Vermont",
"WA"=>"Washington",
"WI"=>"Wisconsin",
"WV"=>"West Virginia",
"WY"=>"Wyoming"
}
include Glimmer::Web::Component
option :full_name
option :street
option :street2
option :city
option :state
option :zip_code
attr_reader :address
before_render do
@address = Address.new(
full_name: full_name,
street: street,
street2: street2,
city: city,
state: state,
zip_code: zip_code,
)
end
markup {
div {
div(style: 'display: grid; grid-auto-columns: 80px 260px;') { |address_div|
label('Full Name: ', for: 'full-name-field')
input(id: 'full-name-field') {
value <=> [address, :full_name]
}
@somelabel = label('Street: ', for: 'street-field')
input(id: 'street-field') {
value <=> [address, :street]
}
label('Street 2: ', for: 'street2-field')
textarea(id: 'street2-field') {
value <=> [address, :street2]
}
label('City: ', for: 'city-field')
input(id: 'city-field') {
value <=> [address, :city]
}
label('State: ', for: 'state-field')
select(id: 'state-field') {
STATES.each do |state_code, state|
option(value: state_code) { state }
end
value <=> [address, :state_code]
}
label('Zip Code: ', for: 'zip-code-field')
input(id: 'zip-code-field', type: 'number', min: '0', max: '99999') {
value <=> [address, :zip_code,
on_write: :to_s,
]
}
style {
r("#{address_div.selector} *") {
margin '5px'
}
r("#{address_div.selector} input, #{address_div.selector} select") {
grid_column '2'
}
}
}
div(style: 'margin: 5px') {
inner_text <= [address, :summary,
computed_by: address.members + ['state_code'],
]
}
}
}
endScreenshot:
To facilitate building formatted textual paragraphs in Ruby, thanks to Glimmer, the most advanced DSL engine in Ruby, the Glimmer HTML DSL is advanced enough to intelligently behave differently under different situations, like when using HTML formatting elements: <br>, <strong>, <em>, <br>, <i>, <sub>, <sup>, <del>, <ins>, <small>, <mark>
Instead of returning Ruby objects that are nested as children within their parent, the Glimmer HTML DSL returns String objects directly that can be concatenated to or embedded within other String objects via interpolation.
This enables writing code like:
p {"#{strong('Yesterday, ')}Robert suggested adding a new #{em('feature')} to our software product.#{br}}
That is close to how it is written in HTML, albeit briefer in Ruby:
<p><strong>Yesterday, </strong>Robert suggested adding a new <em>feature</em> to our software product.<br></p>
Formatting elements just like regular elements can accept text content as their first argument or as their block return value. So, the code above could equally be written as follows:
p {"#{strong{'Yesterday, '}}Robert suggested adding a new #{em{'feature'}} to our software product.#{br}}
This enables seggregating formatting element attributes if desired, as in this example:
p {"#{strong(class: 'very-string'){'Yesterday, '}}Robert suggested adding a new #{em(class: 'very-emphasized'){'feature'}} to our software product.#{br}}
Another way of writing the same code is to pass the text content as the first argument, before attributes:
p {"#{strong('Yesterday, ', class: 'very-string')}Robert suggested adding a new #{em('feature', class: 'very-emphasized')} to our software product.#{br}}
One last bit of info to keep in mind is that <span> generally generates a normal element, except when used inside a <p>'s content block, in which case it is assumed to be used for formatting, so
it returns a String to enable code like this:
p {"#{span('Yesterday, ', style: 'text-decoration: underline;')}Robert suggested adding a new #{em('feature', class: 'very-emphasized')} to our software product.#{br}}
In any case, below is a full example leveraging the Glimmer HTML DSL alternative approach when utilizing formatting elements underneath a paragraph.
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
class HelloParagraph
include Glimmer::Web::Component
markup {
div {
h1(class: 'title') {
'Flying Cars Become 100% Safe with AI Powered Balance!'
}
p(class: 'intro') {"
In the early 2030's, #{em('flying cars')} became affordable after their prices dropped
below #{small(del('$100,000'))}#{ins('$80,000')} as a result of the innovations of #{strong('Travel-X')}. Still, that did not
make #{em('flying cars')} any popular due to the extreme difficulty in piloting such flying vehicles for the average
person, making it very tough to pass the tests for getting a piloting license given the learning curve.
"}
p {"
That said, #{b('Travel-X')} has recently come up with a new feature for their flagship #{i('flying car')},
the Ptero#{sub(1)}#{sup('TM')}, which relies on AI#{sub(2)} to automatically balance the flying cars in mid-air,
thus significantly facilitating their piloting by the average consumer.
"}
p(class: 'conclusion') {"
That Ptero#{sup('TM')} will be so stable and well balanced while flying that the consumer will be able to drive
as if it is a plain old car, with the only difference being vertical elevation, the control of which will be handled
automatically by AI. The Ptero#{sup('TM')} will debut for #{span(style: 'text-decoration: underline dashed;'){'$79,000'}}.
"}
h2(class: 'legend-title') {
mark('Legend:')
}
p(class: 'legend') {"
#{strong("1- Ptero:")} Pterosaur is flying dinosaur species#{br}
#{strong("2- AI:")} Artificial Intelligence#{br}
"}
}
}
end
Document.ready? do
HelloParagraph.render
endScreenshot:
--
--
Glimmer HTML DSL Ruby code in the frontend:
require 'glimmer-dsl-web'
class TimePresenter
attr_accessor :date_time, :month_string, :week_string
def initialize
@date_time = Time.now
end
def month_string
@date_time&.strftime('%Y-%m')
end
def month_string=(value)
if value.match(/^\d{4}-\d{2}$/)
year, month = value.split('-')
self.date_time = Time.new(year, month, date_time.day, date_time.hour, date_time.min)
end
end
def week_string
return nil if @date_time.nil?
year = @date_time.year
week = ((@date_time.yday / 7).to_i + 1).to_s.rjust(2, '0')
"#{year}-W#{week}"
end
def date_time_string
@date_time&.strftime('%Y-%m-%dT%H:%M')
end
def date_time_string=(value)
if value.match(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}$/)
date_time_parts = value.split('T')
date_parts = date_time_parts.first.split('-')
time_parts = date_time_parts.last.split(':')
self.date_time = Time.new(*date_parts, *time_parts)
end
end
end
@time_presenter = TimePresenter.new
include Glimmer
Document.ready? do
div {
div(style: 'display: grid; grid-auto-columns: 130px 260px;') { |container_div|
label('Date Time: ', for: 'date-time-field')
input(id: 'date-time-field', type: 'datetime-local') {
# Bidirectional Data-Binding with <=> ensures input.value and @time_presenter.date_time
# automatically stay in sync when either side changes
value <=> [@time_presenter, :date_time]
}
label('Date: ', for: 'date-field')
input(id: 'date-field', type: 'date') {
value <=> [@time_presenter, :date_time]
}
label('Time: ', for: 'time-field')
input(id: 'time-field', type: 'time') {
value <=> [@time_presenter, :date_time]
}
label('Month: ', for: 'month-field')
input(id: 'month-field', type: 'month') {
value <=> [@time_presenter, :month_string, computed_by: :date_time]
}
label('Week: ', for: 'week-field')
input(id: 'week-field', type: 'week', disabled: true) {
value <=> [@time_presenter, :week_string, computed_by: :date_time]
}
label('Time String: ', for: 'time-string-field')
input(id: 'time-string-field', type: 'text') {
value <=> [@time_presenter, :date_time_string, computed_by: :date_time]
}
style {
r("#{container_div.selector} *") {
margin '5px'
}
r("#{container_div.selector} label") {
grid_column '1'
}
r("#{container_div.selector} input") {
grid_column '2'
}
}
}
}
endScreenshot:
Glimmer HTML DSL Ruby code in the frontend demonstrating MVC + Glimmer Web Components (Views) + Data-Binding:
require 'glimmer-dsl-web'
class Counter
attr_accessor :count
def initialize
self.count = 0
end
end
class ButtonCounter
include Glimmer::Web::Component
before_render do
@counter = Counter.new
end
markup {
div {
button {
# Unidirectional Data-Binding indicating that on every change to @counter.count, the value
# is read and converted to "Click To Increment: #{value} ", and then automatically
# copied to button innerText (content) to display to the user
inner_text <= [@counter, :count,
on_read: ->(value) { "Click To Increment: #{value} " }
]
onclick {
@counter.count += 1
}
}
}
}
end
ButtonCounter.renderThat produces:
<div data-parent="body" class="element element-1">
<button class="element element-2">
Click To Increment: 0
</button>
</div>When clicked:
<div data-parent="body" class="element element-1">
<button class="element element-2">
Click To Increment: 1
</button>
</div>When clicked 7 times:
<div data-parent="body" class="element element-1">
<button class="element element-2">
Click To Increment: 7
</button>
</div>Screenshot:
- The Ruby Way (including TIMTOWTDI: There Is More Than One Way To Do It)
- The Rails Way Convention over Configuration via smart defaults and automation of low-level details
- Requiring the least amount of code possible to build highly interactive web pages
- Declarative syntax that visually maps to the DOM (Document Object Model) hierarchy
- Ability to mix declarative and imperative code conveniently in one language
- Computers serve Software Engineers (not Software Engineers serve Computers)
- Think only about real world concepts directly relevant to web page interaction
- Modular Software Design (e.g. support for Components)
Here is a list of notable 3rd party gems used by Glimmer DSL for Web:
- glimmer-dsl-xml: Glimmer DSL for XML & HTML in pure Ruby.
- glimmer-dsl-css: Glimmer DSL for CSS (Cascading Style Sheets) in pure Ruby.
- opal-async: Non-blocking tasks and enumerators for Web.
- to_collection: Treat an array of objects and a singular object uniformly as a collection of objects.
Glimmer Process is the lightweight software development process used for building Glimmer libraries and Glimmer apps, which goes beyond Agile, rendering all Agile processes obsolete. Glimmer Process is simply made up of 7 guidelines to pick and choose as necessary until software development needs are satisfied.
Learn more by reading the GPG (Glimmer Process Guidelines)
F.A.Q. (Frequently Asked Questions):
How does Glimmer DSL for Web compare to Rails Hotwire (Turbo)?
Glimmer DSL for Web is a Frontend library, meaning it replaces the JavaScript layer in a web application (e.g. Rails app) with Ruby code. On the other hand, Rails Hotwire (Turbo) is mostly a Backend-driven technology that enables automatically replacing HTML DOM elements with HTML markup sent over the wire from a Rails Backend. So, the two technologies are mostly orthogonal, but can be used in the same Rails web application, albeit exclusively on separate web pages at the moment. In the future, there is a plan to explore supporting the ability to combine both technologies in the same pages, but until then, use on separate pages.
How does Glimmer DSL for Web compare to Phlex or ViewComponent?
Glimmer DSL for Web is a Frontend library, meaning it replaces the JavaScript layer in a web application (e.g. Rails app) with Ruby code while providing its own View-layer component support using Glimmer::Web::Component. On the other hand, Phlex and ViewComponent are Backend View-layer component libraries, so they serve 100% orthogonal needs, and can be used side by side with Glimmer DSL for Web if needed (e.g. Phlex components can consist of Backend HTML elements + Glimmer components that are rendered in the Frontend). That said, Phlex came out years after previous Glimmer libraries like Glimmer DSL for SWT, and Phlex's component system is very similar to Glimmer's component system in Glimmer DSL for SWT (perhaps inspired by it unconsciously or consciously). So, if you like Phlex in the Backend, you'll love Glimmer DSL for Web in the Frontend.
How does Glimmer DSL for Web compare to Angular, React, Vue, Svelte, or other JS frameworks?
Without delving into details, Glimmer DSL for Web is meant to be a Ruby-based drop-in replacement for Angular, React, Vue, Svelte, and other JS frameworks. Additionally, it enables writing both structure code and logic code in the same language (Ruby), greatly simplifying maintainability and improving productivity by eliminating multi-language dissonance and friction that drags down productivity as there is no need anymore to think in multiple languages unnecessarily, use XML based solutions (e.g. JSX), or use templating solutions (e.g. Mustache). Lastly, Glimmer DSL for Web supports familiar Software Engineering architectural patterns like Model-View-Controller and Model-View-Presenter, enabling Software Engineers to write the lightest and simplest code possible for building Web frontends in Ruby, with the best separation of concerns. Software Engineers can finally become happy Ruby developers by writing Ruby code in the Frontend too now in addition to the Backend.
How do I have a Glimmer Web Component re-render in a similar way to how React components re-render?
Content Data-Binding supports re-rendering dynamic parts of a Glimmer Web Component (or the full component if all of it is dynamic). Glimmer DSL for Web simplifies Frontend Development significantly over React by not re-rendering everything if not needed (regardless of use of Virtual DOM) yet only re-rendering the parts of a component that do change dynamically. As a result, Software Engineers do not have to worry about the ripple effect of full re-renders or the possibility of breaking some parts of a page when making small changes to a single component in a hierarchy of page components. And, if only an element property changes, Content Data-Binding is not even needed. It is much simpler to rely on simple Property Data-Binding in that case. This makes reasoning about Glimmer DSL for Web Ruby code a lot simpler than reasoning about React component JavaScript code.
How do I reuse React components from Glimmer DSL for Web?
In the future, support for HTML Web Components will be added, and that will enable reuse of React components by using a library that converts them to HTML Web Components first like react-to-web-component or react-webcomponent.
You may submit issues on GitHub.
Click here to submit an issue.
If you need live help, try to
These features have been suggested. You might see them in a future version of Glimmer. You are welcome to contribute more feature suggestions.
- Andy Maleh (Founder)
Click here to view contributor commits.
Copyright (c) 2023-2024 - Andy Maleh. See LICENSE.txt for further details.
--
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