转载:https://github.com/barc/express-hbs
express-hbs
Express handlebars template engine with multiple layouts, blocks and cached partials.
Open source project from Barc, instant real-time forum on any website.
v1.0.0 Breaking Changes
If you're upgrading from v0.8.4 to v1.0.0 there are some potentially breaking changes to be aware of:
- Handlebars @v4.0.5 - please see the handlebars v4.0 compatibility notes
- The file extension for partial files must now match the extension configured in
extname
- please see the PR
Usage
To use with express 4.
var hbs = require('express-hbs');
// Use `.hbs` for extensions and find partials in `views/partials`.
app.engine('hbs', hbs.express4({
partialsDir: __dirname + '/views/partials'
}));
app.set('view engine', 'hbs');
app.set('views', __dirname + '/views');
To use with express 3 is the same as above, except use hbs.express3
app.engine('hbs', hbs.express3({
partialsDir: __dirname + '/views/partials'
}));
Options for #express3
and #express4
hbs.express4({
partialsDir: "{String/Array} [Required] Path to partials templates, one or several directories",
// OPTIONAL settings
blockHelperName: "{String} Override 'block' helper name.",
contentHelperName: "{String} Override 'contentFor' helper name.",
defaultLayout: "{String} Absolute path to default layout template",
extname: "{String} Extension for templates & partials, defaults to `.hbs`",
handlebars: "{Module} Use external handlebars instead of express-hbs dependency",
i18n: "{Object} i18n object",
layoutsDir: "{String} Path to layout templates",
templateOptions: "{Object} options to pass to template()",
beautify: "{Boolean} whether to pretty print HTML, see github.com/einars/js-beautify .jsbeautifyrc,
// override the default compile
onCompile: function(exhbs, source, filename) {
var options;
if (filename && filename.indexOf('partials') > -1) {
options = {preventIndent: true};
}
return exhbs.handlebars.compile(source, options);
}
});
Syntax
To mark where layout should insert page
{{{body}}}
To declare a block placeholder in layout
{{{block "pageScripts"}}}
To define block content in a page
{{#contentFor "pageScripts"}}
CONTENT HERE
{{/contentFor}}
Layouts
There are three ways to use a layout, listed in precedence order
-
Declarative within a page. Use handlebars comment
{{!< LAYOUT}}
Layout file resolution:
If path starts with '.' LAYOUT is relative to template Else If `layoutsDir` is set LAYOUT is relative to `layoutsDir` Else LAYOUT from path.resolve(dirname(template), LAYOUT)
-
As an option to render
res.render('veggies', { title: 'My favorite veggies', veggies: veggies, layout: 'layout/veggie' });
This option also allows for layout suppression (both the default layout and when specified declaratively in a page) by passing in a falsey Javascript value as the value of the
layout
property:res.render('veggies', { title: 'My favorite veggies', veggies: veggies, layout: null // render without using a layout template });
Layout file resolution:
If path starts with '.' layout is relative to template Else If `layoutsDir` is set layout is relative to `layoutsDir` Else layout from path.resolve(viewsDir, layout)
Lastly, use
defaultLayout
if specified in hbs configuration options.
Layouts can be nested: just include a declarative layout tag within any layout
template to have its content included in the declared "parent" layout. Be
aware that too much nesting can impact performances, and stay away from
infinite loops!
Helpers
Synchronous helpers
hbs.registerHelper('link', function(text, options) {
var attrs = [];
for(var prop in options.hash) {
attrs.push(prop + '="' + options.hash[prop] + '"');
}
return new hbs.SafeString(
"" + text + ""
);
});
# in markup
{{{link 'barc.com' href='http://barc.com'}}}
Asynchronous helpers
hbs.registerAsyncHelper('readFile', function(filename, cb) {
fs.readFile(path.join(viewsDir, filename), 'utf8', function(err, content) {
cb(new hbs.SafeString(content));
});
});
# in markup
{{{readFile 'tos.txt'}}}
i18n support
Express-hbs supports i18n
var i18n = require('i18n');
// minimal config
i18n.configure({
locales: ['en', 'fr'],
cookie: 'locale',
directory: __dirname + "/locales"
});
app.engine('hbs', hbs.express3({
// ... options from above
i18n: i18n, // registers __ and __n helpers
}));
app.set('view engine', 'hbs');
app.set('views', viewsDir);
// cookies are needed
app.use(express.cookieParser());
// init i18n module
app.use(i18n.init);
Engine Instances
Create isolated engine instances with their own cache system and handlebars engine.
var hbs = require('express-hbs');
var instance1 = hbs.create();
var instance2 = hbs.create();
Example
in File app.js
// http://expressjs.com/api.html#app.locals
app.locals({
'PROD_MODE': 'production' === app.get('env')
});
File views/layout/default.hbs
{{title}}
{{{block "pageStyles"}}}
{{{body}}}
{{> scripts}}
{{#if PROD_MODE}}
{{{block 'googleAnalyticsScripts'}}}
{{/if}}
File views/index.hbs
{{!< default}}
{{#contentFor 'pageStyles'}}
{{/contentFor}}
{{title}}
Click me!
To run example project
npm install -d
node example/app.js
Testing
The test suite requires the grunt-cli
package:
npm install -g grunt-cli
npm install -d
Once everything's installed, just run:
npm test
Credits
Inspiration and code from donpark/hbs
Big thanks to all CONTRIBUTORS
License
The MIT License (MIT)
Copyright (c) 2012-2014 Barc, Inc.
See file LICENSE for copying permissions.