Update pagination in AngularJS after filtering

Mischa picture Mischa · Apr 22, 2013 · Viewed 45.1k times · Source

I already have the pagination implemented. Now I want the pagination to be updated after filtering my results.

The form:

<input type="text" data-ng-model="search.name" data-ng-change="filter()"/>

The list:

<li data-ng-repeat="data in filtered = (list | filter:search) | filter:search | startFrom:(currentPage-1)*entryLimit | limitTo:entryLimit">{{data.name}}</li>

The pagination:

<pagination data-boundary-links="true" data-num-pages="noOfPages" data-current-page="currentPage" max-size="maxSize"></pagination>

The controller:

$scope.filter = function() {
    window.setTimeout(function() { //wait for 'filtered' to be changed
        $scope.noOfPages = Math.ceil($scope.filtered.length/$scope.entryLimit);
        $scope.setPage = function(pageNo) {
            $scope.currentPage = pageNo;
        };
    }, 10);
};

My problem is, the pagination is just updated after clicking on a page number or after entering the next character into the input field. So it is update one step to late.

EDIT: I added the source to jsFiddle: http://jsfiddle.net/eqCWL/2/

Answer

nackjicholson picture nackjicholson · Dec 20, 2013

@abject_error 's answer using $timeout does work. I edited your fiddle with his suggestion and made this jsFiddle

CAVEAT

I think the solution is indicative of a bigger problem in the form of a race condition!

jsFiddle using filterFilter and $watch

and that fiddle is the way around it for reals.

And here is the explanation

Your race condition is between handling the change of search and the availability of $scope.filtered.

I think the culprits to eliminate in order to resolve this race condition are:

ng-model="search" ng-change="filter()"

and

ng-repeat="data in filtered = (list | filter:search)......."

Using ng-change to fire off "filter()" to do the calculation of noOfPages but also depending on a change in search in order to create filtered. Doing it this way, ensures the filtered list cannot possibly be ready in time to calculate the number of pages, and that's why hobbling "filter()" by 10ms with a timeout gives you the illusion of a working program.

What you need is a way to "watch" search for changes, and then filter the list in a place where you have access to both creating $scope.filtered and calculating $scope.noOfPages. All in sequence, without a race.

Angular has that way! It is possible to use the filter filter in your controller as function very poorly named: filterFilter. Check this out in the Filters Guide - Using filters in controllers and services

Inject it into the controller.

function pageCtrl($scope, filterFilter) {
    // ...
}

Use it in a $watch function, documented in the scopes docs

$scope.$watch('search', function(term) {  
    // Create filtered 
    $scope.filtered = filterFilter($scope.list, term);  

    // Then calculate noOfPages
    $scope.noOfPages = Math.ceil($scope.filtered.length/$scope.entryLimit);  
})

Change the template to reflect our new way. No more in DOM filter, or ng-change

<input type="text" ng-model="search" placeholder="Search"/>

and

<li ng-repeat="data in filtered | startFrom:(currentPage-1)*entryLimit | limitTo:entryLimit">
    {{data.name}}
</li>