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Backend forms

Form behavior is a controller modifier used for easily adding form functionality to a back-end page. The behavior provides three pages Create, Update and Preview. The preview page is a read-only version of the update page. When you use the form behavior you don't need to define the create(), update() and preview() actions in the controller - the behavior does it for you. However you should provide the corresponding view files.

Form behavior depends on form field definitions and a model class. In order to use the form behavior you should add it to the $implement field of the controller class. Also, the $formConfig class property should be defined and its value should refer to the YAML file used for configuring the behavior options.

namespace Acme\Blog\Controllers;

class Categories extends \Backend\Classes\Controller
{
    public $implement = ['Backend.Behaviors.FormController'];

    public $formConfig = 'form_config.yaml';
}

Note: Very often the form and list behavior are used together in a same controller.

Configuring the form behavior

The configuration file referred in the $formConfig property is defined in YAML format. The file should be placed into the controller's views directory. Below is an example of a typical form behavior configuration file:

# ===================================
#  Form Behavior Config
# ===================================

name: Blog Category
form: $/acme/blog/models/post/fields.yaml
modelClass: Acme\Blog\Post

create:
    title: New Blog Post

update:
    title: Edit Blog Post

preview:
    title: View Blog Post

The following fields are required in the form configuration file:

Field Description
name the name of the object being managed by this form.
form a configuration array or reference to a form field definition file, see form fields.
modelClass a model class name, the form data is loaded and saved against this model.

The configuration options listed below are optional. Define them if you want the form behavior to support the Create, Update or Preview pages.

Option Description
defaultRedirect used as a fallback redirection page when no specific redirect page is defined.
create a configuration array or reference to a config file for the Create page.
update a configuration array or reference to a config file for the Update page.
preview a configuration array or reference to a config file for the Preview page.

Create page

To support the Create page add the following configuration to the YAML file:

create:
    title: New Blog Post
    redirect: acme/blog/posts/update/:id
    redirectClose: acme/blog/posts
    flashSave: Post has been created!

The following configuration options are supported for the Create page:

Option Description
title a page title, can refer to a localization string.
redirect redirection page when record is saved.
redirectClose redirection page when record is saved and the close post variable is sent with the request.
flashSave flash message to display when record is saved, can refer to a localization string.
form overrides the default form fields definitions for the create page only.

Update page

To support the Update page add the following configuration to the YAML file:

update:
    title: Edit Blog Post
    redirect: acme/blog/posts
    flashSave: Post updated successfully!
    flashDelete: Post has been deleted.

The following configuration options are supported for the Update page:

Option Description
title a page title, can refer to a localization string.
redirect redirection page when record is saved.
redirectClose redirection page when record is saved and close post variable is sent with the request.
flashSave flash message to display when record is saved, can refer to a localization string.
flashDelete flash message to display when record is deleted, can refer to a localization string.
form overrides the default form fields definitions for the update page only.

Preview page

To support the Preview page add the following configuration to the YAML file:

preview:
    title: View Blog Post

The following configuration options are supported for the Preview page:

Option Description
title a page title, can refer to a localization string.
form overrides the default form fields definitions for the preview page only.

Defining form fields

Form fields are defined with the YAML file. The form fields configuration is used by the form behavior for creating the form controls and binding them to the model fields. The file is placed to a subdirectory of the models directory of a plugin. The subdirectory name matches the model class name written in lowercase. The file name doesn't matter, but fields.yaml and form_fields.yaml are common names. Example form fields file location:

plugins/
  acme/
    blog/
      models/            <=== Plugin models directory
        post/            <=== Model configuration directory
          fields.yaml    <=== Model form fields config file
        Post.php         <=== model class

Fields can be placed in three areas, the outside area, primary tabs or secondary tabs. The next example shows the typical contents of a form fields definition file.

# ===================================
#  Form Field Definitions
# ===================================

fields:
    blog_title:
        label: Blog Title
        description: The title for this blog

    published_at:
        label: Published date
        description: When this blog post was published
        type: datepicker

    [...]

tabs:
    fields:
        [...]

secondaryTabs:
    fields:
        [...]

Tab options

For each tab definition, namely tabs and secondaryTabs, you can specify these options:

Option Description
stretch specifies if this tab stretches to fit the parent height.
defaultTab the default tab to assign fields to. Default: Misc.
cssClass assigns a CSS class to the tab container.

Field options

For each field you can specify these options (where applicable):

Option Description
label a name when displaying the form field to the user.
type defines how this field should be rendered (see Available fields types below). Default: text.
span aligns the form field to one side. Options: auto, left, right, full. Default: auto.
size specifies a field size for fields that use it, for example, the textarea field. Options: tiny, small, large, huge, giant.
placeholder if the field supports a placeholder value.
comment places a descriptive comment below the field.
commentAbove places a comment above the field.
default specifies the default value for the field.
defaultFrom takes the default value from the value of another field.
tab assigns the field to a tab.
cssClass assigns a CSS class to the field container.
disabled grays out the field if set to true. Options: true, false.
hidden hides the field from the view. Options: true, false.
stretch specifies if this field stretches to fit the parent height.
context specifies what context should be used when displaying the field. Context can also be passed by using an @ symbol in the field name, for example, name@update.
dependsOn an array of other field names this field depends on, when the other fields are modified, this field will update.
trigger specify conditions for this field using the trigger interface.
preset allows the field value to be initially set by the value of another field, converted using the input preset converter.
required places a red asterisk next to the field label to indicate it is required.
attributes specify custom HTML attributes to add to the form field element.
containerAttributes specify custom HTML attributes to add to the form field container.

Available field types

There are various native field types that can be used for the type setting. For more advanced form fields, a form widget can be used instead.

Text

text - renders a single line text box. This is the default type used if none is specified.

blog_title:
    label: Blog Title
    type: text

Number

number - renders a single line text box that takes numbers only.

your_age:
    label: Your Age
    type: number

Password

password - renders a single line password field.

user_password:
    label: Password
    type: password

Textarea

textarea - renders a multiline text box. A size can also be specified with possible values: tiny, small, large, huge, giant.

blog_contents:
    label: Contents
    type: textarea
    size: large

Dropdown

dropdown - renders a dropdown with specified options. There are 4 ways to provide the drop-down options. The first method defines options directly in the YAML file:

status:
    label: Blog Post Status
    type: dropdown
    options:
        draft: Draft
        published: Published
        archived: Archived

The second method defines options with a method declared in the model's class. If the options element is omitted, the framework expects a method with the name get*Field*Options() to be defined in the model. Using the example above, the model should have the getStatusOptions() method. This method takes a single parameter, the current key value, and should return an array of options in the format key => label.

status:
    label: Blog Post Status
    type: dropdown

Supplying the dropdown options tn the model class:

public function getStatusOptions($keyValue = null)
{
    return ['all' => 'All', ...];
}

The third global method getDropdownOptions() can also be defined in the model, this will be used for all dropdown field types for the model. This method takes two parameters, the field name and current key value, and should return an array of options in the format key => label.

public function getDropdownOptions($fieldName = null, $keyValue = null)
{
    if ($fieldName == 'status')
        return ['all' => 'All', ...];
    else
        return ['' => '-- none --'];
}

The fourth method uses a specific method declared in the model's class. In the next example the listStatuses() method should be defined in the model class. This method takes two parameters, the current key value and field name, and should return an array of options in the format key => label.

status:
    label: Blog Post Status
    type: dropdown
    options: listStatuses

Supplying the dropdown options tn the model class:

public function listStatuses($keyValue = null, $fieldName = null)
{
    return ['published' => 'Published', ...];
}

Radio List

radio - renders a list of radio options, where only one item can be selected at a time.

security_level:
    label: Access Level
    type: radio
    options:
        all: All
        registered: Registered only
        guests: Guests only

Radio lists can also support a secondary description.

security_level:
    label: Access Level
    type: radio
    options:
        all: [All, Guests and customers will be able to access this page.]
        registered: [Registered only, Only logged in member will be able to access this page.]
        guests: [Guests only, Only guest users will be able to access this page.]

Radio lists support three ways of defining the options, exactly like the dropdown field type. For radio lists the method could return either the simple array: key => value or an array of arrays for providing the descriptions: key => [label, description]

Checkbox

checkbox - renders a single checkbox.

show_content:
    label: Display content
    type: checkbox
    default: true

Checkbox List

checkboxlist - renders a list of checkboxes.

permissions:
    label: Permissions
    type: checkboxlist
    options:
        open_account: Open account
        close_account: Close account
        modify_account: Modify account

Checkbox lists support three ways of defining the options, exactly like the dropdown field type and also support secondary descriptions, found in the radio field type.

Switch

switch - renders a switchbox.

show_content:
    label: Display content
    type: switch
    comment: Flick this switch to display content

Section

section - renders a section heading and subheading. The label and comment values are optional and contain the content for the heading and subheading.

user_details_section:
    label: User details
    type: section
    comment: This section contains details about the user.

Partial

partial - renders a partial, the path value can refer to a partial view file otherwise the field name is used as the partial name. Inside the partial these variables are available: $value is the default field value, $model is the model used for the field and $field is the configured class object Backend\Classes\FormField.

content:
    type: partial
    path: $/acme/blog/models/comments/_content_field.htm

Hint

hint - identical to a partial field but renders inside a hint container that can be hidden by the user.

content:
    type: hint
    path: content_field

Widget

widget - renders a custom form widget, the type field can refer directly to the class name of the widget or the registered alias name.

blog_content:
    type: Backend\FormWidgets\RichEditor
    size: huge

Form widgets

There are various form widgets included as standard, although it is common for plugins to provide their own custom form widgets. You can read more on the Form Widgets article.

Code editor

codeeditor - renders a plaintext editor for formatted code or markup. Note the options may be inherited by the code editor preferences defined for the Administrator in the back-end.

css_content:
    type: codeeditor
    size: huge
    language: html
Option Description
language code language, for example, php, css, js, html. Default: php.
showGutter shows a gutter with line numbers. Default: true.
wrapWords breaks long lines on to a new line. Default true.
fontSize the text font size. Default: 12.

Color picker

colorpicker - renders controls to select a hexadecimal color value.

color:
    type: colorpicker

Date picker

datepicker - renders a text field used for selecting date and times.

published_at:
    label: Published
    type: datepicker
    mode: date
Option Description
mode the expected result, either date, datetime or time. Default: datetime.
minDate the minimum/earliest date that can be selected. Default: 2000-01-01.
maxDate the maximum/latest date that can be selected. Default: 2020-12-31.

File upload

fileupload - renders a file uploader for images or regular files. The field name must use an attachOne or attachMany relation.

avatar:
    label: Avatar
    type: fileupload
    mode: image
    imageHeight: 260
    imageWidth: 260
Option Description
mode the expected file type, either file or image. Default: file.
imageWidth if using image type, the image will be resized to this width, optional.
imageHeight if using image type, the image will be resized to this height, optional.
fileTypes file extensions that are accepted by the uploader, optional. Eg: zip,txt
mimeTypes MIME types that are accepted by the uploader, either as file extension or fully qualified name, optional. Eg: bin,txt
useCaption allows a title and description to be set for the file. Default: true

Record finder

recordfinder - renders a field with details of a related record. Expanding the field displays a popup list to search large amounts of records. Supported by singular relationships only.

user:
    label: User
    type: recordfinder
    list: $/rainlab/user/models/user/columns.yaml
    prompt: Click the %s button to find a user
    nameFrom: name
    descriptionFrom: email
Option Description
nameFrom the column name to use in the relation used for displaying the name. Default: name.
descriptionFrom the column name to use in the relation used for displaying a description. Default: description.
prompt text to display when there is no record selected. The %s character represents the search icon.
list a configuration array or reference to a list column definition file, see list columns.

Media finder

mediafinder - renders a field for selecting an item from the media manager library. Expanding the field displays the media manager to locate a file. The resulting selection is a string as the relative path to the file.

background_image:
    label: Background image
    type: mediafinder
    mode: image
Option Description
mode the expected file type, either file or image. Default: file.
prompt text to display when there is no item selected. The %s character represents the media manager icon.

Relation

relation - renders either a dropdown or checkbox list according to the field relation type. Singular relationships display a dropdown, multiple relationships display a checkbox list.

categories:
    label: Categories
    type: relation
    nameFrom: title
Option Description
nameFrom the column name to use in the relation used for displaying the name. Default: name.
descriptionFrom the column name to use in the relation used for displaying a description (optional). Default: description.
emptyOption text to display when there is no available selections.

Repeater

repeater - renders a repeating set of form fields defined within.

extra_information:
    type: repeater
    form:
        fields:
            added_at:
                label: Date added
                type: datepicker
            details:
                label: Details
                type: textarea
Option Description
form a reference to form field definition file, see backend form fields. Inline fields can also be used.
prompt text to display for the create button. Default: Add new item.

Rich editor / WYSIWYG

richeditor - renders a visual editor for rich formatted text, also known as a WYSIWYG editor.

html_content:
    type: richeditor
    size: huge

Form views

For each page your form supports Create, Update and Preview you should provide a view file with the corresponding name - create.htm, update.htm and preview.htm.

The form behavior adds two methods to the controller class: formRender() and formRenderPreview(). These methods render the form controls configured with the YAML file described above.

Create view

The create.htm view represents the Create page that allows users to create new records. A typical Create page contains breadcrumbs, the form itself, and the form buttons. The data-request attribute should refer to the onSave AJAX handler provided by the form behavior. Below is a contents of the typical create.htm form.

<?= Form::open(['class'=>'layout']) ?>

    <div class="layout-row">
        <?= $this->formRender() ?>
    </div>

    <div class="form-buttons">
        <div class="loading-indicator-container">
            <button
                type="button"
                data-request="onSave"
                data-request-data="close:true"
                data-hotkey="ctrl+enter, cmd+enter"
                data-load-indicator="Creating Category..."
                class="btn btn-default">
                Create and Close
            </button>
            <span class="btn-text">
                or <a href="<?= Backend::url('acme/blog/categories') ?>">Cancel</a>
            </span>
        </div>
    </div>

<?= Form::close() ?>

Update view

The update.htm view represents the Update page that allows users to update or delete existing records. A typical Update page contains breadcrumbs, the form itself, and the form buttons. The Update page is very similar to the Create page, but usually has the Delete button. The data-request attribute should refer to the onSave AJAX handler provided by the form behavior. Below is a contents of the typical update.htm form.

<?= Form::open(['class'=>'layout']) ?>

    <div class="layout-row">
        <?= $this->formRender() ?>
    </div>

    <div class="form-buttons">
        <div class="loading-indicator-container">
            <button
                type="button"
                data-request="onSave"
                data-request-data="close:true"
                data-hotkey="ctrl+enter, cmd+enter"
                data-load-indicator="Saving Category..."
                class="btn btn-default">
                Save and Close
            </button>
            <button
                type="button"
                class="oc-icon-trash-o btn-icon danger pull-right"
                data-request="onDelete"
                data-load-indicator="Deleting Category..."
                data-request-confirm="Do you really want to delete this category?">
            </button>
            <span class="btn-text">
                or <a href="<?= Backend::url('acme/blog/categories') ?>">Cancel</a>
            </span>
        </div>
    </div>

<?= Form::close() ?>

Preview view

The preview.htm view represents the Preview page that allows users to preview existing records in the read-only mode. A typical Preview page contains breadcrumbs and the form itself. Below is a contents of the typical preview.htm form.

<div class="form-preview">
    <?= $this->formRenderPreview() ?>
</div>

Applying conditions to fields

Sometimes you may want to manipulate the value or appearance of a form field under certain conditions, for example, you may want to hide an input if a checkbox is ticked. There are a few ways you can do this, either by using the trigger API or field dependencies. The input preset converter is primarily used to converting field values. These options are described in more detail below.

Input preset converter

The input preset converter is defined with the preset form field option and allows you to convert text entered into an element to a URL, slug or file name value in another input element. Here is a sample definition:

title:
    label: Title

url:
    label: URL
    preset:
        field: title
        type: url

The above example will automatically fill out the url field value when a user enters text in the title field. If the text Hello world is typed in for the Title, the URL will follow suit with the converted value of /hello-world. This behavior will only occur when the destination field (url) is empty and untouched.

Option Description
field defines the other field name to source the value from.
type specifies the conversion type. Supported values are: url, file, slug, camel.
prefixInput optional, prefixes the converted value with the value found in the supplied input element using a CSS selector.

The preset value can also be a string that refers to the field only, the type option will then default to slug.

Trigger API

The trigger API is defined with the trigger form field option and is a simple browser based solution that uses JavaScript. It allows you to change elements attributes such as visibility or value, based on another elements' state. Here is an sample definition:

is_delayed:
    label: Send later
    comment: Place a tick in this box if you want to send this message at a later time.
    type: checkbox

send_at:
    label: Send date
    type: datepicker
    cssClass: field-indent
    trigger:
        action: show
        field: is_delayed
        condition: checked

In the above example the send_at form field will only be shown if the is_delayed field is checked. In other words, the field will show (action) if the other form input (field) is checked (condition). The trigger definition specifies these options:

Option Description
action defines the action applied to this field when the condition is met. Supported values: show, hide, enable, disable, empty.
field defines the other field name that will trigger the action.
condition determines the condition the specified field should satisfy for the condition to be considered "true". Supported values: checked, value[somevalue].

Field dependencies

Form fields can depend on others when defining the dependsOn form field option which provides a more robust server side solution. When the defined other fields change, the defining field will update using the AJAX framework. Here is a sample definition:

    country:
        label: Country
        type: dropdown

    state:
        label: State
        type: dropdown
        dependsOn: country

In the above example the state form field will refresh when the country field has a changed value. When this occurs, the current form data will be filled in the model so the dropdown options can use it.

public function getCountryOptions()
{
    return ['au' => 'Australia', 'ca' => 'Canada'];
}

public function getStateOptions()
{
    if ($this->country == 'au') {
        return ['act' => 'Capital Territory', 'qld' => 'Queensland', ...];
    }
    elseif ($this->country == 'ca') {
        return ['bc' => 'British Columbia', 'on' => 'Ontario', ...];
    }
}

This example is useful for manipulating the model values, but it does not have access to the form field definitions. You can filter the form fields by defining a filterFields() method inside the model, described in the Filtering form fields section.

Extending form behavior

Sometimes you may wish to modify the default form behavior and there are several ways you can do this.

Overriding controller action

You can use your own logic for the create(), update() or preview() action method in the controller, then optionally call the Form behavior parent method.

public function update($recordId, $context = null)
{
    //
    // Do any custom code here
    //

    // Call the FormController behavior update() method
    return $this->asExtension('FormController')->update($recordId, $context);
}

Extending model query

The lookup query for the form database model can be extended by overriding the formExtendQuery method inside the controller class. This example will ensure that soft deleted records can still be found and updated, by applying the withTrashed scope to the query:

public function formExtendQuery($query)
{
    $query->withTrashed();
}

Extending form fields

You can extend the fields of another controller from outside by calling the extendFormFields static method on the controller class. This method can take three arguments, $form will represent the Form widget object, $model represents the model used by the form and $context is a string containing the form context. Take this controller for example:

class Categories extends \Backend\Classes\Controller
{
    public $implement = ['Backend.Behaviors.FormController'];

    public $formConfig = 'form_config.yaml';
}

Using the extendFormFields method you can add extra fields to any form rendered by this controller. It is a good idea to check the $model is of the correct type. Here is an example:

    Categories::extendFormFields(function($form, $model, $context){

        if (!$model instanceof MyModel)
            return;

        $form->addFields([
            'my_field' => [
                'label'   => 'My Field',
                'comment' => 'This is a custom field I have added.',
            ],
        ]);

    });

You can also extend the form fields internally by overriding the formExtendFields method inside the controller class.

class Categories extends \Backend\Classes\Controller
{
    [...]

    public function formExtendFields($form)
    {
        $form->addFields([...]);
    }
}

The following methods are available on the $form object.

Method Description
addFields adds new fields to the outside area
addTabFields adds new fields to the tabbed area
addSecondaryTabFields adds new fields to the secondary tabbed area
removeField remove a field from the tabbed area

Each method takes an array of fields similar to the form field configuration.

Filtering form fields

You can filter the form field definitions by overriding the filterFields() method inside the Model used. This allows you to manipulate visibility and other field properties based on the model data. The method takes two arguments $fields will represent an object of the fields already defined by the field configuration and $context represents the active form context.

public function filterFields($fields, $context = null)
{
    if ($this->source_type == 'http') {
        $fields->source_url->hidden = false;
        $fields->git_branch->hidden = true;
    }
    elseif ($this->source_type == 'git') {
        $fields->source_url->hidden = false;
        $fields->git_branch->hidden = false;
    }
    else {
        $fields->source_url->hidden = true;
        $fields->git_branch->hidden = true;
    }
}

The above example will set the hidden flag on certain fields by checking the value of the Model attribute source_type. This logic will be applied when the form first loads and also when updated by a defined field dependency.