decor contains a simple-to-user yet powerful template loader
for Golang mainly focussed on the built-in
packages text/template and html/template.
While these packages provide powerful templating facilities with great support for rendering textual content, using these packages to build a complete layout-based template solution involves a lot of boilerplate code. decor tries to fill this gap by providing just what's needed to reduce the boilerplate and enable a great developer experience.
$ go get github.com/halimath/decor
Decor requires go >= 1.16.
The core components provided by decor is the Templates struct which
provides the rendering functionality of templates. When creating an instance
you need to provide a Loader which is responsible for loading a named template.
decor provides a files loader for both text and html templates that includes
capabilities to load layout files as well.
tpls := decor.Templates{
Includes: []string{
"layouts/base",
},
Loader: text.NewFilesLoader("%s.txt", "testtemplates"),
}
if err := tpls.ExecuteTemplate(os.Stdout, "a", "world"); err != nil {
log.Fatal(err)
}The above snippet configures a Templates value and effectively executes something like.
t, _ := "text/template".ParseFiles("testtemplates/a.txt", "testtemplates/layouts/base.txt")
t.Execute(os.Stdout, "world")Note that error handling as well as template caching is omitted from the example; the two lines above only sketch what's happening.
By default templates loaded are put into a cache the first time they are loaded. The Templates struct
is safe to use across multiple goroutines, so loading and rendering template in parallel works out of the
box. Internally, Templates uses an efficient sync.RWLock to guard access to the thread.
You can put Templates into development mode by setting its DevelMode-Field to true. This
completely disables the cache and templates are loaded using the loader every time they are executed.
This is great during development when changes made to templates become immediately effective.
Its a common case to render a template producing HTML as part of a web server application using the
net/http package. decor provides a utility function to handle this case as a one liner:
Templates.SendHTML. The method accepts a http.ResponseWriter, a template name and template data
and directly writes any output rendered from template to the HTTP response. The method also sets the
content type to text/html as well as the content length.
When in development mode (see above), any errors generated during rendering will be send to the HTTP client for debugging. When not in development mode, errors will be logged and the response will be empty.
The files in package html are generated from the corresponding files in package text. The code
generation tool can be found in cmd/gen-html.
Copyright 2021 Alexander Metzner Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.