hogan-xpress
v2.0.0
Published
Mustache template engine for express 3 and 4. Supports partials, layouts, and lambdas
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tandrewnicholsReadme
hogan-xpress
Mustache template engine for express 3 and 4. Supports partials, layouts, and lambdas.
Uses twitter's hogan.js engine.
Supports
- Partials (Allows you to modularize, to move pieces of templates to their own file - think of these as "included" templates)
- Layouts (Allows you to consolidate common elements of your templates - think of these as "parent" templates)
- Caching (Makes your app more efficient by reducing unnecessary rendering)
- Lambdas (Allows you to create custom filters/lambdas)
Migration Note
If you are coming from hogan-express (no longer maintained):
I've migrated away from coffeescript (I'm sure no one will miss that). I've also cleaned up a few minor, known bugs, but not all the open bugs/pull requests from the original project, so please feel free to reopen issues and/or resubmit pull requests. Also, I don't have a bounty of free time, so if you're interested in helping maintain this, please email me. I'd much rather have several contributors/maintainers than a single point of failure (as we had on the previous project).
The major focus of this project still has to be performance, so while adding features is nice, it can't be at the cost of speed. This migration was originally about 4/100s of a second slower rendering a complicated page. To try to assure we maintain performance, I've added benchmarking tests and, over time, I've been able to improve the rendering performance of this library to where it competes with or is better than the original library. However, the last time I tried using this library, there was definitely a memory leak. But I was still using essentially the same code as the old library, just updated to javascript (and not the coffeescript generated kind). I've recently completely restructured this, so hopefully that will resolve the memory leak issue.
Installation
npm install --save hogan-xpress
Usage
Setup
To use hogan-xpress, map the file extension of your choice to the
hogan-xpress engine in your app setup. For example:
app.set('view engine', 'html') // use .html extension for templates
app.set('layout', 'layout') // use layout.html as the default layout
app.set('partials', {foo: 'foo'}) // define partials available to all pages
app.enable('view cache')
app.engine('html', require('hogan-xpress'))Rendering a template
Within your app route callback, define res.locals and call res.render, passing any partials required by your template. For example:
app.get('/', function(req, res) {
res.locals = { name: 'Andrew' }
res.render('template', { partials: {message: 'message'} })
})This would render the layout (layout.html, defined in setup) using the template (template.html) and the specified partials (message.html).
If layout.html contained:
<p>
<strong>Message Layout</strong>
{{{ yield }}}
</p>and template.html contained:
<em>{{ name }} says {{> message }}</em>and message.html contained:
Hello World.the callback would produce:
<p>
<strong>Message Layout</strong>
<em>Andrew says Hello World.</em>
</p>The special {{{ yield }}} variable in layout.html indicates the location in your layout file where your template is rendered. You can define your layout using app.set 'layout', ... or specify it when calling res.render. If a layout is not provided, the template is rendered directly.
Custom yield tags
You can define more extension points in layout.html using custom tags {{yield-<name>}}. For example:
layout:
<head>
...
{{{yield-styles}}}
{{{yield-scripts}}}
...
</head>index:
{{#yield-styles}}
<style>
...
</style>
{{/yield-styles}}
{{#yield-scripts}}
<script>
...
</script>
{{/yield-scripts}}The page index.html will be rendered into {{yield}} without the content in {{#yield-styles}}...{{/yield-styles} and {{#yield-scripts}}...{{/yield-scripts}}. That content goes into accordingly named tags in layout.html. If {{{yield-styles}}} is missing, the styles tag content will not be rendered.
Custom layouts
To render a page with custom layout, just specify it in the options: res.render "admin.html", layout: "admin-layout"
Custom Lambdas / Filters
To create custom filters (or lambdas) you can just specify your filter functions in the options:
app.get('/', function(req, res) {
res.locals = { myDefaultLabel: "oops" } // here to show a little of how scoping works
res.render('template', {
message: 'This is a message. HERE.',
mylist: [{label: "one", num: 1},{label: "two", num: 2},{num: 3}],
lambdas: {
lowercase: function(text) {
return text.toLowerCase()
},
reverseString: function(text) {
return text.split("").reverse().join("")
}
}
})
});Your function will recieve the fully interpolated string (not the pre-rendered template snippet).
It will also receive a second parameter which is the context in which the lambda was called (this works within loops too) including top-level stuff that would be in res.locals for example. You shouldn't normally need this, but there are a few use cases for having access to that data.
template:
<p>Lowercase <strong>{{message}}</strong>: {{#lambdas.lowercase}}{{message}}{{/lambdas.lowercase}}</p>
<ul>
{{#mylist}}
<li>{{num}}: {{label}} is {{#lambdas.reverseString}}{{label}}{{#lambdas.reverseString}} in reverse.</li>
{{/mylist}}
</ul>rendered html:
<p>Lowercase <strong>This is a message. HERE.</strong>: this is a message. here.</p>
<ul>
<li>1: one is eno in reverse.</li>
<li>2: two is owt in reverse.</li>
<li>3: oops is spoo in reverse.</li>
</ul>License
hogan-xpress is released under the MIT License
Contributing
Please see the contribution guidelines.