Can XMLHttpRequest data be stored in localStorage?

Question

I am writing a Safari extension that makes an XMLHttpRequest for some XML data using jQuery.ajax. If I do console.log(data) in the process data function, I get an item Document which I can traverse.

I want to store this ajax data in localStorage. So in the first few lines of the processDocument function I have this:

function processResponse(data) {
    localStorage.removeItem("myData");
    localStorage.setItem("myData", data);
    console.log('post-load: there are ' + localStorage.length + ' items in the local storage array.');
    console.log("post-load data: " + data);
    console.log("post-load myData: " + localStorage.myData);

The console.log will show me:
post-load: there are 1 items in the local storage array.
post-load data: [object Document]
post-load myData: [object Document]

So it looks like I have valid data here. But the messageHandler function when it responds to the button on the toolbar also polls the local storage like this:

console.log('There are ' + localStorage.length + ' items in the local storage array.');
for (var x = 0; x < localStorage.length; x++) {
    console.log(x + ": " + localStorage[x]);
}
if (localStorage.myData == undefined) {
    console.log("myData is undefined");
    doSomething();
} else {
    console.log("myData is defined");
    doSomethingElse();
}

The console log here will show:
There are 1 items in the local storage array.
0: undefined
myData is defined

Is there something I need to do in order to properly store this XML data in localStorage? Shouldn't localStorage preserve the integrity of this object? Perhaps I am missing something here.

score 1 · Answer 1 · edited May 23 '17 at 12:13

1

Despite what your initial debug output appears to be telling you, Local storage doesn't store objects it stores strings. To get XML back you should store it as a string and then parse the string back into XML when you retrieve it. This answer describes one approach, you may need to adapt it specifically for XML.

edited May 23 '17 at 12:13

Community

1
1

answered Feb 03 '11 at 18:09

robertc

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Well, I see JSON.stringify and it looks like the direction I am going in. Is there such a beast for regular old XML? – gdanko Feb 03 '11 at 21:11
var string = (new XMLSerializer()).serializeToString(data); – gdanko Feb 03 '11 at 21:51
@user589254 XML parsing is one of those things [that works very differently in IE compared to most other browsers](http://www.mikechambers.com/blog/2006/01/09/parsing-xml-in-javascript/), you might want to investigate some of the lightweight AJAX libraries. – robertc Feb 03 '11 at 23:39

Can XMLHttpRequest data be stored in localStorage?

1 Answers1