Develop Reference

How can I make sure ajax/jquery calls finish before an html page loads?

$(function() {
var $items = $('#items');
$.ajax({
type: "GET",
url: 'some-url',
data: {},
success: function(items) {
$.each(items, function(i, item){
item_polys.push(item.polygon);
$items.append(`<a href="somepage.html" onclick="localStorage.setItem('item', '${item.item_id}'); localStorage.setItem('item_poly', '${item.polygon}')";>${item.item_id}</a>`);
});
localStorage.setItem('item_polys', JSON.stringify(item_polys));
},
// Error handling
error: function (error) {
console.log(`Error ${error}`);
},
});
I need 'item_polys' to be saved into local storage before my corresponding html page loads. I would also settle for a way to reload the html page just one time each time after it loads, so that it will populate correctly. Thanks (and sorry if this has been answered already, I couldn't quite find what I was looking for when I searched)

Since you want the ajax request to occur when the user is on the exact same page that the populated elements will be in, I think the only good way of doing this would be to create or display the elements of the page dynamically. (This might be as simple as toggling a display: none on and off, but it depends on what the page is like and what you want.)
So, make a function like populatePage that shows the page, where the default state of the page is a loading screen (or blank, or whatever you want the user to see when the request is in progress). Maybe something like
const populatePage = () => {
const items = JSON.parse(localStorage.items);
for (const item of items) {
$items.append(`<a href="somepage.html" onclick="localStorage.setItem('item', '${item.item_id}'); localStorage.setItem('item_poly', '${item.polygon}')";>${item.item_id}</a>`);
}
$('main').show();
};
where main is the container you want to show when things are ready, and that has styling that hides it by default. Then:
On pageload, check if the item exists in storage. If so, use it, and call populatePage immediately. Otherwise, have the page keep showing the loading banner or blank screen, make the ajax request, and call populatePage when it's finished.
$.ajax({
// ...
success: function (items) {
localStorage.items = JSON.stringify(items);
populatePage();

DurandalJS and jQuery not adding to Select

I am creating a SPA in DurandalJS with MVC, and have jQuery loading a <select> with options loaded from a database. Setting breakpoints i was able to follow the stack all the way down the chain and verify that all of my ajax loading and jQuery calls were occuring, but when I go to check the select box, it is empty, including the inner html of the tag and the dropdown elements themselves.
What's weird though is that the items will load if I navigate to another page and then come back to the original page (since this is an ajax-ified single page application it doesn't actually navigate in the traditional sense.
Why is this happening and how can I fix it?
Code to load the data:
function addProjectSelectorOptions(projects) {
$('#project-picker').empty();
for (var i = 0; i < projects.length; i++) {
console.log(projects[i]);
$('#project-picker').append(new Option(projects[i]["Name"], projects[i]["Id"]));
}
}
function loadData() {
$.ajax({
url: '/ClubhouseData/GetProjects',
type: 'GET',
cache: false,
success: function (results) {
console.log(results);
addProjectSelectorOptions(results);
}
});
};
loadData();

Solved:
I wrapped loadData() in a jQuery onDocumentLoad call and it fixed the problem.

JQuery - Looping a .load() inside a 'for' statement

I'm not sure if this will actually be possible, since load() is an asynchronous method, but I need some way to basically Load several little bits of pages, one at a time, get some data included in them via JavaScript, and then send that over via Ajax so I can put it on a database I made.
Basically I get this from my page, where all the links I'll be having to iterate through are located:
var digiList = $('.2u');
var link;
for(var i=0;i<digiList.length;i++){
link = "http://www.digimon-heroes.com" + $(digiList).eq(i).find('map').children().attr('href');
So far so good.
Now, I'm going to have to load each link (only a specific div of the full page, not the whole thing) into a div I have somewhere around my page, so that I can get some data via JQuery:
var contentURI= link + ' div.row:nth-child(2)';
$('#single').load('grabber.php?url='+ contentURI,function(){
///////////// And I do a bunch of JQuery stuff here, and save stuff into an object
///////////// Aaaand then I call up an ajax request.
$.ajax({
url: 'insertDigi.php',
type: 'POST',
data: {digimon: JSON.stringify(digimon)},
dataType: 'json',
success: function(msg){
console.log(msg);
}
////////This calls up a script that handles everything and makes an insert into my database.
}); //END ajax
}); //END load callback Function
} //END 'for' Statement.
alert('Inserted!');
Naturally, as would be expected, the loading takes too long, and the rest of the for statement just keeps going through, not really caring about letting the load finish up it's business, since the load is asynchronous. The alert('Inserted!'); is called before I even get the chance to load the very first page. This, in turn, means that I only get to load the stuff into my div before I can even treat it's information and send it over to my script.
So my question is: Is there some creative way to do this in such a manner that I could iterate through multiple links, load them, do my business with them, and be done with it? And if not, is there a synchronous alternative to load, that could produce roughly the same effect? I know that it would probably block up my page completely, but I'd be fine with it, since the page does not require any input from me.
Hopefully I explained everything with the necessary detail, and hopefully you guys can help me out with this. Thanks!

You probably want a recursive function, that waits for one iteration, before going to the next iteration etc.
(function recursive(i) {
var digiList = $('.2u');
var link = digiList.eq(i).find('map').children().attr('href') + ' div.row:nth-child(2)';
$.ajax({
url: 'grabber.php',
data: {
url: link
}
}).done(function(data) {
// do stuff with "data"
$.ajax({
url: 'insertDigi.php',
type: 'POST',
data: {
digimon: digimon
},
dataType: 'json'
}).done(function(msg) {
console.log(msg);
if (i < digiList.length) {
recursive(++i); // do the next one ... when this is one is done
}
});
});
})(0);

Just in case you want them to run together you can use closure to preserve each number in the loop
for (var i = 0; i < digiList.length; i++) {
(function(num) { < // num here as the argument is actually i
var link = "http://www.digimon-heroes.com" + $(digiList).eq(num).find('map').children().attr('href');
var contentURI= link + ' div.row:nth-child(2)';
$('#single').load('grabber.php?url=' + contentURI, function() {
///////////// And I do a bunch of JQuery stuff here, and save stuff into an object
///////////// Aaaand then I call up an ajax request.
$.ajax({
url: 'insertDigi.php',
type: 'POST',
data: {
digimon: JSON.stringify(digimon)
},
dataType: 'json',
success: function(msg) {
console.log(msg);
}
////////This calls up a script that handles everything and makes an insert into my database.
}); //END ajax
}); //END load callback Function
})(i);// <-- pass in the number from the loop
}

You can always use synchronous ajax, but there's no good reason for it.
If you know the number of documents you need to download (you can count them or just hardcode if it's constant), you could run some callback function on success and if everything is done, then proceed with logic that need all documents.
To make it even better you could just trigger an event (on document or any other object) when everything is downloaded (e.x. "downloads_done") and listen on this even to make what you need to make.
But all above is for case you need to do something when all is done. However I'm not sure if I understood your question correctly (just read this again).
If you want to download something -> do something with data -> download another thing -> do something again...
Then you can also use javascript waterfall (library or build your own) to make it simple and easy to use. On waterfall you define what should happen when async function is done, one by one.

How to load new content to DIV without refreshing [duplicate]

This question already has answers here:
how to reload DIV content without refreshing whole page
(8 answers)
Closed 9 years ago.
I want to load new content from the server to the DIV without refreshing the whole page.
I tried the following
$.ajax({
type: "GET",
url: "http://127.0.0.1:8000/result/?age="+ ageData +"&occasion="+
occasionData +"&relationship="+ forData +"#",
success: function (response) {
$("#testDIV").html(response);
}
});
But the problem is the whole page is loading in <DIV id="testDIV">. I want to replace the old DIV with New DIV content returned from the server not with the whole page.

You can keep your same process sense you are interested in using AJAX directly and want to manage your done function (instead of success because .done() will replace it). Here is how...
.done(function(data) {
...
}
Inside of that done function, you can filter the page content to what you want. Simply request what you want to filter with jquery like this...
var $response = $(data);
var response_title = $response.filter(".title").html(); //I'm assuming you are trying to pull just the title (perhaps an < h1 > tag, in this little example, from the entire external page!
THEN!...
$("#testDIV").html(response_title);
With the done function, based on jQuery's API, you can use this format...
$.ajax({
type: "POST",
url: "some.php",
data: { name: "John", location: "Boston" }
}).done(function( msg ) {
alert( "Data Saved: " + msg );
});
So your final code may look something like this...
$.ajax({
type: "GET",
url: "ht.tp://127.0.0.1:8000/result/?age="+ ageData +"&occasion="+ occasionData +"&relationship="+ forData +"#"})
.done(function(response) {
var $response = $(response);
var response_title = $response.filter(".title").html();
$("#testDIV").html(response_title);
});

I like the answer by blackhawk. It uses the existing code with slight modification.
I would just condense it to a one line change like this:
$.ajax({
type: "GET",
url: "http://127.0.0.1:8000/result/?age="+ ageData +"&occasion="+
occasionData+"&relationship="+ forData +"#",
success: function (response) {
$("testDIV").html($(data).filter(".title").html());
}
});

The code you are displaying is actually correct.
The problem comes from what your server is providing.
What you are doing here is GETing a whole page via an AJAX call, and replacing the content of One div with that whole page.
Your server should not render the whole page for that call, but only the content of the div you wish to replace. If you are using framework like rails or symfony, they often provide an easy way to detect if the query is a normal GET request, or an AJAX call.
Basically you have 4 strategies at your disposal :
Make the requests to a specific endpoint that is used only for the ajax call and that returns the content of the div you wish to replace. And not the whole page.
Make the request to the same page, and detect if the request is a normal HTTP request or an AJAX call. Based on that, return the whole page or just the content of the div. You'll probably have to look for the helpers in your framework / toolbox documentation.
Make the AJAX request but ask for a JSON object. Transform your JSON in HTML on the client side to replace the content of the div. This is the "my app is just an API" approach. This is my personal favorite as this JSON endpoint can be used for other purposes (eg: a mobile app) since it carries only content, and not presentation. This also tends to be the fastest way in terms of performance since a significant part of the computation is done on the client side. On the con side, this requires you to write more JS.
Always render the whole page, and filter only what you need on the client side. This is balchawk approach. Benefit is that you don't have to modify your server, but you will waste processing time and bandwidth by returning a whole page, when only a subset is necessary.

$(function(){
$('.classloader.').on('click', function(e){
$.ajax({
type: "GET",
url: "http://127.0.0.1:8000/result/?age="+ ageData +"&occasion="+
occasionData +"&relationship="+ forData +"#",
beforeSend: function() {
$("#testDIV").hide();
$('div#loading').show();
},
success: function(html){
$("#testDIV").html($(html).filter("#mainContent").html()).show();
$('div#loading').hide();
}
});
return false;
});
})

Calling ajax from within js file on users browser

I have a bookmarklet which a user adds to their own browser bookmarks toolbar which collects images from a page they are looking at.
I want to log each time a user is clicking on any site and store the data in a mysql table. So i'm using an ajax call to post to a php file which processes the data sent to it.
However, this sometimes works and sometimes does not. Meaning, it works on some sites and not others.
What I'm trying is this:
(function()
{ // declare variables e.g. div.ids, div content etc then display it
......
//log the click
var dataString = '&url=' + encodeURIComponent(window.location.href) + '&page_title=' + encodeURIComponent(document.title);
$.ajax({
type: "POST", // form method
url: "http://myurl.com/includes/log_clicks.php",// destination
data: dataString,
cache: false
});
//END log the click
})();
When it doesn't work and i use Firebug to find out why, i sometimes get the error: TypeError: $ is undefined $.ajax({
Sometimes it still posts to the php file but with no data
Is there a better way to call ajax from within a js file on a user's browser?
As per suggestions, I've tried loading jquery by simply amending one of the variables like so:
div.innerHTML = '<script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script><div class=....';
But that made no difference

You need jQuery present on the page in order to perform this. You will need to load jQuery if not present. A great approach is outlined here using the jQuerify code which actually just loads a portion of jQuery functionality that is needed.