How to create a custom Filter with AngularJS

A few days ago I needed to create a custom filter to truncate a piece of text with a specific length and with a custom ending, something like this: “This is an Examp…”.

Before I continue, I want to refer that AngularJS is on version 1.0. At this version the documentation is not yet completed.

The creation of custom filters only needs three things:

1. Create the module
2. Create the filter and his function
3. Register the module in the application

1. Create the module

1	angular.module('yourModuleName', [])

2. Create the filter and his function

1 2 3 4 5 6

angular.module('yourModuleName', [])     .filter('yourFilterName', function () {         return function () {             return;         };     });

3. Register the module in the application

1	angular.module('yourAppName', ['yourModuleName']);

Example: Truncate Filter

01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18

angular.module('filters', []).     filter('truncate', function () {         return function (text, length, end) {             if (isNaN(length))                 length = 10;             if (end === undefined)                 end = "...";             if (text.length <= length || text.length - end.length <= length) {                 return text;             }             else {                 return String(text).substring(0, length-end.length) + end;             }         };     });

You can see this example on this gist and run it on jsfiddle.

Note: This can not be the best practice implementation, but was the result I achieved and solved my problem.