JSON.parse Jquery timing issue/conflict

Question

This service returns valid JSON data

var gridValsstr;
$.ajax({
    type: "GET",
        url: "InsertMessage",
        cache: false,
        success: function(data)
        {
            //  alert(data);
            gridValsstr = data;
        },
        error: function(xhr, status, error) {
            alert(xhr.responseText);
        }
});

However on this line:

var gridvals = JSON.parse(gridValsstr);

I get the error:

SyntaxError: JSON.parse: unexpected character

Which then causes the rest of my script to fail...

However if I put a break point at that line and wait for a few seconds the line processes correctly and loads the JSON into the UI. So I'm thinking it is processing too quickly or the variable isn't completely ready yet or something?

Your code does not show a `var gridvals = JSON.parse(gridValsstr);` line. Regardless, why aren't you using [`$.getJSON()`](http://api.jquery.com/jQuery.getJSON)? — Matt Ball, Jan 14 '14 at 23:12
Your setup looks like a dupe of http://stackoverflow.com/q/14220321/1331430 — Fabrício Matté, Jan 14 '14 at 23:16
Thx Fabricio. Matt -- I need to send options, I thought $.getJSON() didn't accept those, anyways. thx. — user3196063, Jan 15 '14 at 16:29

score 0 · Accepted Answer · answered Jan 14 '14 at 23:19

0

Most likely because the Ajax call is asynchronous and your JSON.parse line is running before the request has completed.

The break point is pausing execution long enough for the Ajax request to complete.

answered Jan 14 '14 at 23:19

Jon Miles

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score 0 · Answer 2 · answered Jan 15 '14 at 16:33

Followed the link from Fabricio, looks like the async request didn't complete before I was trying to access the var. So below code solved the problem. Remember to also put any code that interacts with the result of the call into the .done(){.....} and it will work.

getFilters().done(function(r) {
if(r) {
    gridValsstr = r;
    gridvals = JSON.parse(gridValsstr);     
}
else
{
    //alert("r sucks");
}
})
.fail(function(x) {
    alert("didn't work.")
});

JSON.parse Jquery timing issue/conflict

2 Answers2