Include all javascript files in a directory to a html file in angularjs? with grunt?

Answering the general question of adding source files to index.html on demand and automatically and elaborating on the use of grunt-include-source.

This is for the following folder structure:

MyProject
|
+-- index.js
+-- Gruntfile.js
+-- package.json
+-- //other files
|
+--+ app
   +-- //app files (.html,.js,.css,.*)

1. Install with npm i -D grunt-include-source grunt-contrib-watch.

2. In your Gruntfile.js, add grunt.loadNpmTasks('grunt-include-source');

3. Then you have to add a bunch of tasks to your Gruntfile.js, after which it should look like this:

   module.exports = function (grunt) {
       grunt.initConfig({
           pkg: grunt.file.readJSON('package.json'),
           //...
           watch: {
               //...
               includeSource: {
                   // Watch for added and deleted scripts to update index.html
                   files: ['app/**/*.js','app/**/*.css'],
                   tasks: ['includeSource'],
                   options: {
                       event: ['added', 'deleted']
                   }
               }
           },
           includeSource: {
               options: {
                   //This is the directory inside which grunt-include-source will be looking for files
                   basePath: 'app'
               },
               app: {
                   files: {
                       //Overwriting index.html
                       'app/index.html': 'app/index.html'
                   }
               }
           }
       });
   
       //...
       grunt.loadNpmTasks('grunt-contrib-watch');
       grunt.loadNpmTasks('grunt-include-source');
   
       //...
       //Include sources, run the server, open the browser, and watch.
       grunt.registerTask('default', ['includeSource', 'watch']);
   };
   

4. In your index.html, add this (the file path here looks inside the base path set in Gruntfile.js):

   <!-- include: "type": "css", "files": "**/*.css" -->
   <!-- /include -->
   <!-- include: "type": "js", "files": "**/*.js" -->
   <!-- /include -->
   

5. Finally, on the command line:

   grunt
   

This should start off all tasks in sequence, and your index.html should be updated accordingly when a JS or CSS is added or removed.

This is how your index.html might look like with a small number of files:

<!-- include: "type": "css", "files": "**/*.css" -->
<link href="styles.css" rel="stylesheet" type="text/css">
<!-- /include -->
<!-- include: "type": "js", "files": "**/*.js" -->
<script src="_routes/routes.js"></script>
<script src="scripts/app.js"></script>
<!-- /include -->

Links:

• https://www.npmjs.com/package/grunt-include-source
• https://ajsblackbelt.wordpress.com/2014/07/07/free-from-include/
• https://jhipster.github.io/tips/002_tip_include_js_grunt.html

You can use something like this:

(function loadScript() {
    var head = document.getElementsByTagName("head")[0];
    var done = false;

    var directory = 'libraries/';
    var extension = '.js';
    var files = ['functions', 'speak', 'commands', 'wsBrowser', 'main']; 

     for (var file of files){ 
        var path = directory + file + extension; 
        var script = document.createElement("script");
        script.src = path;

        script.onload = script.onreadystatechange = function() {
        // attach to both events for cross browser finish detection:
        if ( !done && (!this.readyState ||
           this.readyState == "loaded" || this.readyState == "complete") ) {
           done = true;
           // cleans up a little memory:
           script.onload = script.onreadystatechange = null;
           // to avoid douple loading
           head.removeChild(script);
        }
    };
  head.appendChild(script); 
  done = false;
 }
})();