jquery ajax and pipe

Question

I have the following code:

(saveData())
.pipe(function(data){return sendhandovermail($('#editperson_id').val());})
.pipe(function(data){setHistory(_eciId,'4','12',true);})
.pipe(function(data){window.location.href = 'input.cfm?m=4&id=45';})
.fail(function(data){$('##msgDialogDetail').html("Error while saving. Please contact bla@blup.com");});

The code works (no errors) but... I was told .pipe() method will do all ajax calls one after the other. IF A returns, B will start. Though when I run it, it's not the case. Am I understanding it wrong, or how should I write this chain to have it execute one after the other?

yes. First argument is `doneFilter` that will be executed once the first ajax request is completed and i think all will be executed in parallel. — Amareswar, Oct 15 '12 at 18:23
I assume saveData makes an ajax request and returns a deferred object. All pipes are applied on that deferred object unless every function is not returning a deferred object and thats why all functions within pipe will be executed in parallel. — Amareswar, Oct 15 '12 at 18:30
then all functions will be executed synchronously one after the other — Amareswar, Oct 15 '12 at 18:33
but that's my problem, they're not executing one after the other. The refresh happens before the setHIstory() — PoeHaH, Oct 15 '12 at 18:35
@PoeHaH, you're ignoring the value returned by `setHistory()`, not returning it. — Frédéric Hamidi, Oct 15 '12 at 18:36
may be this link helps http://stackoverflow.com/questions/5921283/understanding-jquery-deferred-pipe — Amareswar, Oct 15 '12 at 18:38

score 0 · Answer 1 · answered Mar 11 '19 at 06:07

how should I write this chain to have it execute one after the other?

you should return a promise in pre pipe and the later will run according the promise that pre pipe returned.

like this:

var posting = $.post('/step1', data1)
            .pipe(function () {
                return $.post('/step2', data2);
            })
            .pipe(function () {
                return $.post('/step3', data3);
            });

we should use then function instead of pipe in 1.8+ jQuery.

jquery ajax and pipe

1 Answers1