karma-ng-html2js-preprocessor

 

  

> Preprocessor for converting HTML files to AngularJS 1.x and Angular 2 templates.

Note: If you are looking for a general preprocessor that is not tied to Angular, check out karma-html2js-preprocessor.

Installation

The easiest way is to keep karma-ng-html2js-preprocessor as a devDependency in your package.json. Just run

``bash
$ npm install karma-ng-html2js-preprocessor --save-dev
`

Configuration


`js
// karma.conf.js
module.exports = function(config) {
config.set({
preprocessors: {
'*/.html': ['ng-html2js']
},

files: [
'*.js',
'*.html',
'*.html.ext',
// if you wanna load template files in nested directories, you must use this
'*/.html'
],

// if you have defined plugins explicitly, add karma-ng-html2js-preprocessor
// plugins: [
//
// 'karma-ng-html2js-preprocessor',
// ]

ngHtml2JsPreprocessor: {
// strip this from the file path
stripPrefix: 'public/',
stripSuffix: '.ext',
// prepend this to the
prependPrefix: 'served/',

// or define a custom transform function
// - cacheId returned is used to load template
// module(cacheId) will return template at filepath
cacheIdFromPath: function(filepath) {
// example strips 'public/' from anywhere in the path
// module(app/templates/template.html) => app/public/templates/template.html
var cacheId = filepath.strip('public/', '');
return cacheId;
},

// - setting this option will create only a single module that contains templates
// from all the files, so you can load them all with module('foo')
// - you may provide a function(htmlPath, originalPath) instead of a string
// if you'd like to generate modules dynamically
// htmlPath is a originalPath stripped and/or prepended
// with all provided suffixes and prefixes
moduleName: 'foo'
}
})
}
`

$3

Use function if more than one module that contains templates is required.

`js
// karma.conf.js
module.exports = function(config) {
config.set({
// ...

ngHtml2JsPreprocessor: {
// ...

moduleName: function (htmlPath, originalPath) {
return htmlPath.split('/')[0];
}
}
})
}
`

If only some of the templates should be placed in the modules,
return '', null or undefined for those which should not.

`js
// karma.conf.js
module.exports = function(config) {
config.set({
// ...

ngHtml2JsPreprocessor: {
// ...

moduleName: function (htmlPath, originalPath) {
var module = htmlPath.split('/')[0];
return module !== 'tpl' ? module : null;
}
}
})
}
`




How does it work ?

This preprocessor converts HTML files into JS strings and generates Angular modules. These modules, when loaded, puts these HTML files into the $templateCache and therefore Angular won't try to fetch them from the server.

For instance this template.html...
`html



`
... will be served as template.html.js:
`js
angular.module('template.html', []).run(function($templateCache) {
$templateCache.put('template.html', '

something

')
})
`

See the ng-directive-testing for a complete example.

----

Angular2 template caching

For using this preprocessor with Angular 2 templates use angular: 2 option in the config file.

`js
// karma.conf.js
module.exports = function(config) {
config.set({
// ...

ngHtml2JsPreprocessor: {
// ...

angular: 2
}
})
}
`

The template template.html...
`html



`
... will be served as template.html.js that sets the template content in the global $templateCache variable:
`js
window.$templateCache = window.$templateCache || {}
window.$templateCache['template.html'] = '

something

';
`

To use the cached templates in your Angular 2 tests use the provider for the Cached XHR implementation - CACHED_TEMPLATE_PROVIDER from angular2/platform/testing/browser. The following shows the change in karma-test-shim.js to use the cached XHR and template cache in all your tests.
`js
// karma-test-shim.js
...
System.import('angular2/testing').then(function(testing) {
return System.import('angular2/platform/testing/browser').then(function(providers) {
testing.setBaseTestProviders(
providers.TEST_BROWSER_PLATFORM_PROVIDERS,
[providers.TEST_BROWSER_APPLICATION_PROVIDERS, providers.CACHED_TEMPLATE_PROVIDER]);
});
}).then(function() {
...
`

Now when your component under test uses template.html in its templateUrl` the contents of the template will be used from the template cache instead of making a XHR to fetch the contents of the template. This can be useful while writing fakeAsync tests where the component can be loaded synchronously without the need to make a XHR to get the templates.

---

For more information on Karma see the [homepage].

[homepage]: http://karma-runner.github.com