Express handlebars template engine complete with multiple layouts, partials and blocks.
npm install express-hbsExpress handlebars template engine with multiple layouts, blocks and cached partials.
Version 2 was a rewrite and cleanup, with no known breaking changes. Lots of bugs were fixed which may have subtly changed behaviour.
Full details: https://github.com/TryGhost/express-hbs/releases/tag/2.0.0
If you're upgrading from v0.8.4 to v1.0.0 there are some potentially breaking changes to be aware of:
1. Handlebars @v4.0.5 - please see the handlebars v4.0 compatibility notes
2. The file extension for partial files must now match the extension configured in extname - please see the PR
To use with express 4.
``js
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
`js`
app.engine('hbs', hbs.express3({
partialsDir: __dirname + '/views/partials'
}));
Options for #express3 and #express4
`js
hbs.express4({
partialsDir: "{String/Array} [Required] Path to partials templates, one or several directories",
// OPTIONAL settings
restrictLayoutsTo: "{String} Absolute path to a directory to restrict layout directive reading from",
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);
}
});
`
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}}
There are three ways to use a layout, listed in precedence order
1. Declarative within a page. Use handlebars comment
{{!< LAYOUT}}
Layout file resolution:
If path starts with '.'
LAYOUT is relative to template
Else If layoutsDir is setlayoutsDir
LAYOUT is relative to
Else
LAYOUT from path.resolve(dirname(template), LAYOUT)
2. As an option to render
## ⚠️ This creates a potential security vulnerability if used without a restrictLayoutsTo:
The restrictLayoutsTo option will restrict reading layouts to a particular directory, if you do not pass this option then do not use the layout option in conjunction with passing user submitted data to res.render e.g. res.render('index', req.query). This allows users to read arbitrary files from your filesystem!
`js`
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:
`js`
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 setlayoutsDir
layout is relative to
Else
layout from path.resolve(viewsDir, layout)
3. 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!
`js`
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'}}}
`js`
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'}}}
Express-hbs supports i18n
`js
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);
`
Create isolated engine instances with their own cache system and handlebars engine.
`js`
var hbs = require('express-hbs');
var instance1 = hbs.create();
var instance2 = hbs.create();
The main use case for template options is setting the handlebars "data" object - this creates global template variables accessible with an @ prefix.
Template options can be set in 3 ways. When setting global template options they can be passed as config on creation of an instance, and they can also be updated used the updateTemplateOptions(templateOptions) method of an instance. To set template options for an individual request they can be set on res.locals using the helper method updateLocalTemplateOptions(locals, templateOptions).
Both of these methods have a companion method getTemplateOptions() and getLocalTemplateOptions(locals), which should be used when extending or merging the current options.
in File app.js
`js
// http://expressjs.com/api.html#app.locals
app.locals({
'PROD_MODE': 'production' === app.get('env')
});
`
File views/layout/default.hbs
`html
{{{block "pageStyles"}}}
{{{body}}}
{{> scripts}}
{{#if PROD_MODE}}
{{{block 'googleAnalyticsScripts'}}}
{{/if}}
`
File views/index.hbs
`html
{{!< default}}
{{#contentFor 'pageStyles'}}
{{/contentFor}}
Click me!
To run example project
npm install -d
node example/app.js
Testing
The test suite requires the
npm install -g grunt-cli
npm install -d
Once everything's installed, just run:
npm test
Inspiration and code from donpark/hbs
Big thanks to all CONTRIBUTORS
The MIT License (MIT)
Copyright (c) 2012-2023 Barc, Inc., Ghost Foundation - Released under the MIT license.