Showing posts with label angular-highlightjs. Show all posts
Showing posts with label angular-highlightjs. Show all posts


August 01, 2017
AngularJS directive for syntax highlighting with highlight.js.



  • Highlight.js v7.0.0+
  • AngularJS v1.0.1+

Getting started

Follow the instructions here to setup highlight.js.
Using a prebuilt version of highlight.js hosted at cdnjs here.
 <!-- personal preference: github theme -->  
 <link rel="stylesheet" href="//">  
 <script src="//"></script>  
Include angular-highlightjs module script with AngularJS script on your page.
 <script src="//"></script>  
 <script src=""></script>  
Add hljs to your app module's dependency.
 angular.module('myApp', ['hljs']);  

Install with npm

 npm install angular-highlightjs  

Install with Bower

There's currently no official bower package of highlight.js (see here). You should either build highlight.js yourself or use the pre-built one on cdnjs.
 bower install angular-highlightjs  


Configuration works with highlight.js >= 8.0
In configuration phase, call hljsServiceProvider.setOptions() to configure with highlight.js options.
 myApp.config(function (hljsServiceProvider) {  
   // replace tab with 4 spaces  
   tabReplace: '  '  

Directive usage


This is a required directive. Without any other supportive directives, it provides basic inline highlight function. For better understanding, some notes about using it are specified in the live example page.
The directive automatically escapes its content HTML entities by default. Can be turned off with explicitly configuration hljs-escape="{expression evaled to false}" or hljs-no-escape, and they're only applicable for "just-hljs" usage. Live example
 <!-- hljs start -->  
 <div hljs>  
 <!-- put your codes here -->  
 <!-- hljs end -->  
 <!-- Will get the same result as above -->  
 <div hljs  
 &lt;!-- put your codes here --&gt;  

Frequently Asked Question

Since the code inside hljs will be parsed by browser even before AngularJS bootstraped, it sometimes demonstrates strange highlight result when the code you put inside hljs have HTML-tag-like syntax (). To deal with the issue, use hljs-no-escape option with manually escaped code or switch to hljs-source or hljs-include for highlighting.

hljs-source (optional)

Type: expression Default: undefined
If hljs-source is presented, the hljs directive will evaluate the expression and highlight the result string. This is pretty useful for dynamically changed content.
Live example Dynamically changed content.
 <!-- buttons for put/clear $scope.subSource content -->  
 <button class="btn btn-primary show-source"   
     ng-show="!subSource">put $scope.subSource</button>  
 <button class="btn btn-primary show-source"   
     ng-show="subSource">clear $scope.subSource</button>  
 <div ng-show="subSource">  
  <!-- hljs connected with $scope.subSource -->  
  <div hljs  
The expression. Beware of single-quotes.
 <!-- hljs connected with independent string -->  
 <div hljs  

hljs-include (optional)

Type: expression Default: undefined
Works as the built-in ng-include directive, utilizes $templateCache and $http to retrieve content from text/ng-template scripts or from XHR.
Live example
From text/ng-template script localOne. Beware of single-quotes in the expression.
 <!-- load text/ng-template named 'localOne' -->  
 <div hljs  
From partials/lang-perl XHR. Again, beware of single-quotes.
 <!-- load "partials/lang-perl" -->  
 <div hljs  

hljs-language (optional)

Type: string Default: undefined
Tells the highlight.js which language syntax should be used to highlight the codes. If not specified, highlight.js will highlight with built-in language detection.
Live example
 <!-- PHP codes highlight with language detection -->  
 <div hljs   
 <!-- PHP codes highlight with specified language: perl -->  
 <div hljs   

hljs-interpolate (optional)

Type: expression Default: undefined
Interpolates the highlighted code and links it with current scope.
The attribute works with all methods of highlighting: hljs, hljs-source and hljs-include.
Live example
 <div hljs  

Happy highlighting!!!

Note: Special thanks to Chih-Hsuan Fan
Disclaimer: The blog is created to share angular directives information to geek, curious Angular Developers.