Of Stack

Use AngularJS to create a custom filter

  • 2020-06-15 07:48:57
  • OfStack

The Angularjs filter is one of the great features of angularjs. One day, you may need to use a custom filter. Fortunately, you found this post.

Here's what the custom filter looks like (note myfilter):

Our custom filter is called "myfilter" and it has four parameters separated by ':'.

Here is a sample input that will be used: 



  $scope.friends = [{name:'John', phone:'555-1276'}, 
           {name:'Annie', phone:'800-BIG-MARY'}, 
           {name:'Mike', phone:'555-4321'}, 
           {name:'Adam', phone:'555-5678'}, 
           {name:'David', phone:'555-8765'}, 
           {name:'Mikay', phone:'555-5678'}];

The filter only shows the item with "555" in the phone number, which is the sample output: 



 Name   Phone 
 John   555-1276 
 Mike   555-4321 
 Adam   555-5678 
 David   555-8765 
 Mikay   555-5678

The process of filtering "555" is performed by "windowScopedFilter", which is the fourth parameter of the filter 'myfilter'.

Let's implement these functions (adding logging to each input parameter): 


 var myapp = angular.module('MyFilterApp', []); 
 myapp.filter('myfilter', function() { 
  return function(input, param1) { 
   console.log("------------------------------------------------- begin dump of custom parameters"); 
   console.log("input=",input); 
   console.log("param1(string)=", param1); 
   var args = Array.prototype.slice.call(arguments); 
   console.log("arguments=", args.length); 
   if (3<=args.length) { 
      console.log("param2(string)=", args[2]); 
   } 
   if (4<=args.length) { 
      console.log("param3(bool)=", args[3]); 
   } 
   console.log("------------------------------------------------- end dump of custom parameters"); 
   // filter 
   if (5<=args.length) { 
      return window[args[4]](input); 
   } 
   return input; 
  }; 
 });

Much of the code above is log. The most important part of actually doing the filtering is: 


   // filter 
   if (5<=args.length) { 
      return window[args[4]](input); 
   } 
   return input;


"return window[args[4]](input)" calls the fourth argument, which is 'windowScopedFilter'.

This is the console output: 


 
 "------------------------------------------------- begin dump of custom parameters" custom_filter_function.html:21 
 "input=" [object Array] custom_filter_function.html:22 
 "param1(string)=" "param1" custom_filter_function.html:23 
 "arguments=" 5 custom_filter_function.html:25 
 "param2(string)=" "param2" custom_filter_function.html:27 
 "param3(bool)=" true custom_filter_function.html:30 
 "------------------------------------------------- end dump of custom parameters" custom_filter_function.html:32 
 "------------------------------------------------- begin dump of custom parameters" custom_filter_function.html:21 
 "input=" [object Array] custom_filter_function.html:22 
 "param1(string)=" "param1" custom_filter_function.html:23 
 "arguments=" 5 custom_filter_function.html:25 
 "param2(string)=" "param2" custom_filter_function.html:27 
 "param3(bool)=" true custom_filter_function.html:30 
 "------------------------------------------------- end dump of custom parameters" custom_filter_function.html:32

Complete code: 


<html> 
 <head> 
 <script src="angular.min.js"></script> 
 <script type="text/javascript"> 
 function windowScopedFilter (input) { 
   var output = []; 
   angular.forEach(input, function(v,k){ 
      if (v.phone.contains("555")) { 
        output.push(v); 
      } 
   }); 
   return output;    
 } 
 var myapp = angular.module('MyFilterApp', []); 
 myapp.filter('myfilter', function() { 
  return function(input, param1) { 
   console.log("------------------------------------------------- begin dump of custom parameters"); 
   console.log("input=",input); 
   console.log("param1(string)=", param1); 
   var args = Array.prototype.slice.call(arguments); 
   console.log("arguments=", args.length); 
   if (3<=args.length) { 
      console.log("param2(string)=", args[2]); 
   } 
   if (4<=args.length) { 
      console.log("param3(bool)=", args[3]); 
   } 
   console.log("------------------------------------------------- end dump of custom parameters"); 
   // filter 
   if (5<=args.length) { 
      return window[args[4]](input); 
   } 
   return input; 
  }; 
 }); 
 myapp.controller('MyFilterController', ['$scope', function($scope) { 
  $scope.friends = [{name:'John', phone:'555-1276'}, 
           {name:'Annie', phone:'800-BIG-MARY'}, 
           {name:'Mike', phone:'555-4321'}, 
           {name:'Adam', phone:'555-5678'}, 
           {name:'David', phone:'555-8765'}, 
           {name:'Mikay', phone:'555-5678'}]; 
 }]); 
 </script> 
 </head> 
 <body ng-app="MyFilterApp"> 
 <div ng-controller="MyFilterController"> 
   <table id="searchTextResults"> 
    <tr><th>Name</th><th>Phone</th></tr> 
    <tr ng-repeat="friend in friends |myfilter:'param1':'param2':true:'windowScopedFilter'"> 
    <td>{{friend.name}}</td> 
    <td>{{friend.phone}}</td> 
    </tr> 
   </table> 
 </div> 
 <hr> 
 </body> 
 </html>

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