Creating a specialized filter for AngularJS or customizing an existing one

Question

Creating a specialized filter for AngularJS or customizing an existing one

AngularJS filters are great, but I want to enhance them by adding a function that can check if a value is in an array.

For example, let's say we have the following data:

Queue = [
    {'Name':'John','Tier':'Gold','Status':'VIP'},
    {'Name':'Anna','Tier':'Silver','Status':'Normal'},
    {'Name':'Luke','Tier':'Gold','Status':'Normal'},
    {'Name':'Mary','Tier':'Bronze','Status':'Normal'},
    {'Name':'Jess','Tier':'Bronze','Status':'VIP'},
];
Priority = ['Gold','Silver'];

I want to display the names of Priority members who are also VIPs.

<div ng-repeat="people in Queue | filter: {Tier:Priority} | filter: {Status:'VIP'}">{{ people.Name }}</div>

I would like to update the filter so it can compare Tier with items in the Priority array.

I've tried creating a custom filter with AngularJS, but I'm struggling to make it as versatile as the existing one, which can handle objects, strings, and functions seamlessly.

My focus isn't just on checking if an item exists in an array, but on developing a filter that can differentiate between strings and arrays while maintaining the functionality of the current filter.

javascript angularjs

Answer 1

Answer №1

To implement a custom filter, I will utilize regular expressions in this scenario.

Within the .html file:

<body ng-app="myApp">
   <tr ng-repeat="item in Queue | regex:'Tier':Priority | filter:{Status :'VIP'}">
</body>

The custom filter code is as follows:

var myApp = angular.module('myApp', []);
myApp.filter('regex', function() {
  return function(input, field, priList) {
     var result = [];
     var priListExp = priList.join("|");
     var patt = new RegExp(priListExp, "i"); // remove "i" for case sensitive
      input.forEach( function(pri){
         if(patt.test(pri[field])) {
           result.push(pri);
         }
     });

  return result;
  }
});

See the demo here: Plunker

Answer 2

To implement a custom filter, I will utilize regular expressions in this scenario.

Within the .html file:

<body ng-app="myApp">
   <tr ng-repeat="item in Queue | regex:'Tier':Priority | filter:{Status :'VIP'}">
</body>

The custom filter code is as follows:

var myApp = angular.module('myApp', []);
myApp.filter('regex', function() {
  return function(input, field, priList) {
     var result = [];
     var priListExp = priList.join("|");
     var patt = new RegExp(priListExp, "i"); // remove "i" for case sensitive
      input.forEach( function(pri){
         if(patt.test(pri[field])) {
           result.push(pri);
         }
     });

  return result;
  }
});

See the demo here: Plunker

Answer 3

Answer №2

Here's a concept, not an operational code snippet. If you provide arguments in the filter function, you could implement it like this:

module.filter('filterName', function() {
return function(input, tier, status) {
 if (input.Tier == tier)
 {
  //perform action
 }
 if (input.Status == status)
 {
  //perform action
 }
 return input;
}   
});

In your HTML:

<div ng-repeat="people in Queue | filterName:'Priority':'VIP'">{{ people.Name }}</div>

Answer 4

Here's a concept, not an operational code snippet. If you provide arguments in the filter function, you could implement it like this:

module.filter('filterName', function() {
return function(input, tier, status) {
 if (input.Tier == tier)
 {
  //perform action
 }
 if (input.Status == status)
 {
  //perform action
 }
 return input;
}   
});

In your HTML:

<div ng-repeat="people in Queue | filterName:'Priority':'VIP'">{{ people.Name }}</div>

Creating a specialized filter for AngularJS or customizing an existing one

Answer №1

Answer №2

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