CODEWITHSUNDEEP
javascriptangularjsajaxrace-condition
paiego
paiego

Reputation: 3787

Race condition with an Angular 1 Service for an Ajax call

Fairly new to Angular...

So If I'm using Ajax (rather than $http) in an Angular service, I want to keep a reference to a callback function. I suspect that there may be a race condition here with the this.callback variable.

Can another session come in and stomp on this.callback while the first session is still doing the Ajax call?

var myServer = angular.module("mymod", ["my.server"]);

myServer.service("$myservice",         

    function($server) 
    {
        var me = this;        
        this.callback = null; 

        this.saveDone = function(data)
        {
            if (me.callback) me.callback();
        }

        this.save = function(item, cb)
        {
            me.callback = cb; 

            dict = {"name" : "savePDataStory"};
            dict.item = item;        
            actions = [dict];

            $server.realAjaxCall(actions, this.saveDone, true);
        }

Upvotes: 0

Views: 88

Answers (1)

aaronm
aaronm

Reputation: 26

Yes. Each call to save will overwrite this.callback since it is shared across calls to save. A solution is to store the callback inside save itself which will be unique per invocation of the function. You can do this inline like so:

$server.realAjaxCall(actions, function (data) {
    cb();
}, true);

This preserves the behavior of the original code snippet which doesn't include data when callback is called. If you don't mind passing data through to callback, you can simplify it by using cb directly instead of wrapping it inside a function:

$server.realAjaxCall(actions, cb, true);

Upvotes: 1

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