CODE CUSTOM CONTROLLER:

var UriListing = "http://wp.org/wp-json/wp/v2/posts/";    
$scope.updateListing=function(keyword){
$scope.fetchURL = UriListing + "?search="+keyword;
       $scope.fetchURLp = UriListing + "?search="+keyword+"&callback=JSON_CALLBACK";
       $scope.hashURL = md5.createHash($scope.fetchURL.replace(targetQuery,raplaceWithQuery));
$ionicLoading.show();
$scope.doRefresh();
}

CODE HTML:

  <div class="item item-input-inset">
    <label class="item-input-wrapper">
      <input type="text" placeholder="Keyword" ng-model="keyword">
    </label>
    <button class="button button-small" ng-click="updateListing(keyword)">Search</button>
  </div>