how to show a spinner using a filter in angularjs? -

i using filter show values in table. values fetching ajax calls , want show spinner while values fetching. wrote:

app.filter("fetchedvalue", function(){     return function(fetchedvalue){             if(angular.isundefined(fetchedvalue)){                     return "image";//this spinner             }else if(fetchedvalue === null){                     return "na";             }             else{                     return fetchedvalue;             }     } }); 

it not working. not sure how spinner when value undefined. know how it?

i think misunderstand filter for. function should return true or false depending if want value given function filtered or not.

see https://docs.angularjs.org/api/ng/filter/filter , angularjs custom filter function

to answer question though, forget filter, , use ng-if or ng-show or ng-hide on <img> when value undefined.

<img ng-hide="fetchedvalue" src="spinner.gif" /> 

this assumes fetched value truthy. more robust solution set flag in block of request promise, , ng-hide based on flag.