Preventing a race condition in asynchronous Ajax call - ajax

I am using Javascript below to pull content into Bootstrap-4 popover, and I think that it has a race condition:
$(function () {
$('[data-toggle="popover"]').popover({
html: true
, content: function () {
// Pull URL from data-remote-ref of the element that triggered the popover
var url = $(this).data('remote-ref');
// Make a temporary element ID for the spinner
var spinnerId = "loading-id-" + $.now();
// Initiate an asynchronous Ajax call
$.get(url, function (data) {
$('#'+spinnerId).html(data);
});
// Return temporary content with the spinner
return '<div id="' + spinnerId + '">'
+ '<div class="spinner-border" role="status">'
+ '<span class="sr-only">Loading...</span>'
+ '</div>'
+ '</div>';
}
});
});
This code fires up an Ajax $.get request, and then returns <div id="loading-id-..."> to be rendered.
At this point, $('#loading-id-...') does not exist yet, so the browser starts working on adding it to the page.
If Ajax callback happens before the browser has finished constructing the spinner, $('#loading-id-...') inside function (data) would yield nothing, so the remote content would never get rendered.
Assuming that my assumptions are correct, and there is no special "magic" built into the browser to prevent race conditions of this kind, is there a way to fix this race condition?

Related

Can't get wordpress ajax form to submit

I am porting an application to WordPress. It uses a form to select what attributes the customer is looking for in an Adult Family Home via checkboxes and drop-downs. It re-searches the database on each onchange and keyup. Originally I had the application standalone in PHP, but when I migrated it to WordPress I started having issues.
Currently in WP I have the code conditionalized ($DavesWay == 1) to do ajax the normal no-WordPress-way and ($DavesWay == 0) to do it the WordPress-way.
In the non-WordPress-way, the ajax works fine EXCEPT that I get a WP header and menu between the search form and the results-div that Ajax puts the data in. I get no errors from WP or in the JS console. In the WP-way The search form displayed, but nothing happens when I check any of the checkboxes. The JS console displays
POST http://localhost/demo4/wp-admin/admin-ajax.php 400 (Bad Request)
But I don't see any way to tell exactly what it is complaining about. How should I troubleshoot this?
Troubleshooting = Examine the HTML output, lots of echos and exits in PHP code, look at JS console.
function submitPg1(theForm) {
// Used with onChange from "most" form elements, but not on those that change the page
// rather than the select criteria. Such as rowsPerPage, pageNumber etc.
setById("pageNo", "1"); // set inital page
mySubmit();
}
function mySubmit(theForm) { // The actual ajax submit
// DO NOT set page number
jQuery.ajax({ // create an AJAX call...
data: jQuery("#asi_search_form").serialize(), // get the form data
type: jQuery("#asi_search_form").attr("method"), // GET or POST
url: jQuery("#asi_search_form").attr("action"), // the file to call
success: function (response) { // on success..
jQuery("#result").html(response); // update the DIV
}
})
}
function setById(id, value) { // Used to set vales by Id
x = document.getElementById(id).value;
x.value = value;
}
// 1st submit with blank selection
jQuery(document).ready(function () { submitPg1(this.form) });
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
Code fragments: (from the displayed page source)
<div id="asi_container" class="asi_container" >
<noscript><h2>This site requires Javascript and cookies to function. See the Help page for how to enable them.</h2></noscript>
<div id="searchForm">
<form id="asi_search_form" name="asi_search_form" method="post" action="http://localhost/demo4/wp-admin/admin-ajax.php">
<input type="hidden" name="action" value="asi_LTCfetchAll_ajax" style="display: none; visibility: hidden; opacity: 0;">
<table id="greenTable" class="asi_table" title="The Green areas are for site administration, not typical users">
<tbody>
PHP code:
$DavesWay = 0;
if ($DavesWay == 1){ //echo "Daves Way Setup"; // Dave's way, which works but prints the menu twice
if( $operation == "submit"){
require("asi_LTCfetchAll.php"); // for each onchange or onkeyup
}else{
add_filter( 'the_content', 'asi_tc_admin', '12' ); // Initial page refresh # must be >12
}
}else{
// The WordPress way that I could't get to work -- asi_LTCfetch never gets called
function asi_LTCfetchAll_ajax(){
//echo "<br /> Goto to Submit function"; // DEBUG
require($asi_plugin_dir . "/includes" . '/asi_LTCfetchAll.php');
}
add_action( "wp_ajax_asi_LTCfetchAll_ajax", "asi_LTCfetchAll_ajax" ); // admin users
add_action( "wp_ajax_nopriv_asi_LTCfetchAll_ajax", "asi_LTCfetchAll_ajax" ); // non-logged in users
add_filter( "the_content", "asi_tc_admin", "12" ); // Initial page refresh # must be >12
}
Try changing the JavaScript to the way WordPress recommends it in their documentation:
var data = {
'action': 'my_action',
'whatever': 1234
};
jQuery.post(ajaxurl, data, function(response) {
alert('Got this from the server: ' + response);
});
I suggest trying following URL: https://codex.wordpress.org/AJAX_in_Plugins
Also you can use the plugin: https://wordpress.org/plugins/ajax-search-lite/

Magento2 Knockout.js contentUpdated not binding observables after ajax.

I have an issue with observables being fired after content is updated via ajax and javascript is re-initialized via .trigger('contentUpdated'). This all works when the scripts are rendered initially on page load but when they are added via ajax I cannot get the observables to update. For demo purposes I've simplified by logic but basically I have a block that gets loaded via ajax for a product collection like so:
myblock.phtml
<div class="wrapper-id-1">
<!-- this is what gets appended via ajax
<div id="product-item-<?php echo $productId;?>">
<span data-bind="text: someObservable()"></span>
...
</div>
<script type="text/x-magento-init">
{
"#product-item-<?php echo $productId;?>": {
"path/to/component":{
"some":"vars"
}
}
</script>
<!--and ajax append ends here -->
</div>
In the component that gets bound to the element I have:
component.js
...
this.someObservable: ko.observable('default value'),
initialize: function () {
var self = this;
this.anotherComponentModel().value.subscribe(function(data){
self.someObservable(data['value']);
},this);
},
...
the ajax that calls and loads the collection:
ajaxComponent.js
$.ajax({
url: 'route/to/controller?cat=' + categoryId,
success: function (data) {
$('.wrapper-id-' + categoryId).empty().append('<h2>' + categoryTitle + '</h2>' + data).show().trigger('contentUpdated');
}
})
...
I see that the component(component.js) gets initialized when contentUpdated is triggered and it has all of the correct data that is needed. However the observables to not fire and the data is not updated to the DOM. This an issue with scope? Or to I need to re-initialize the observables? I tried doing this via not binding directly to the component ie:
<script type="text/x-magento-init">
{
// components initialized without binding to an element
"*": {
"<js_component3>": ...
}
}
</script>
but it achieves the same result.
What am I missing here.

How can I return an id value from a div already populated through ajax

I am having some difficulty passing a correct id function back to AJAX.
I'm creating a product bulletin generator that lets items to be added by their SKU code (which works fine). My problem is that when a bulletin is clicked on, a preview of that bulletin is loaded into a div and shows all products associated with that bulletin.
From inside those results, I am trying to add the ability to delete a product from the bulletin. The problem is that the value being passed back to AJAX belongs to the first product only. It won't send the value belonging to the particular item if it is any other item than the first one.
This is the code (belonging to main.php) that gets loaded via AJAX into a div and is looped with each product associated with a selected bulletin
echo "<form name='myDelForm'>
$news_gen_id<br>
<input type='hidden' id='delccode' value='".$news_gen_id."'>
<input type='hidden' id='deledit' value='".$edit."'>
<input type='button' onclick='ajaxDelCcode()' value='Delete' /><br></form>
</td>";
The AJAX code (on index.php, where the div that calls in main.php is also located) is this
function ajaxDelCcode(){
var ajaxRequest; // The variable that makes Ajax possible!
try{
// Opera 8.0+, Firefox, Safari
ajaxRequest = new XMLHttpRequest();
} catch (e){
// Internet Explorer Browsers
try{
ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try{
ajaxRequest = new
ActiveXObject("Microsoft.XMLHTTP");
} catch (e){
// Something went wrong
alert("Your browser broke!");
return false;
}
}
}
// Create a function that will receive data sent from the server
ajaxRequest.onreadystatechange = function(){
if(ajaxRequest.readyState == 4){
var ajaxDisplay = document.getElementById("ajaxMain2");
ajaxDisplay.innerHTML = ajaxRequest.responseText;
}
}
var deledit = document.getElementById("deledit").value;
var delccode = document.getElementById("delccode").value;
var queryString = "?delccode=" + delccode + "&deledit=" + deledit;
ajaxRequest.open("GET", "main.php" + queryString, true);
ajaxRequest.send(null);
}
//-->
</script>
Currently, using those two pieces of code, I can successfully delete only the first product. The delccode variables do not seem to change when the products are looped (although when I echo the variables during the loop, it is definitely changing to the appropriate value...it's just not passing it correctly back to AJAX.)
I tried taking the AJAX code, putting it inside the main.php product loop, and change the function name during each loop (so ajaxDelCcode$news_gen_id() for example) and also to the button itself so that it is calling the AJAX specific to it. And it works if you are visiting main.php directly...but not from index.php after main.php has been called into the div.
I can't figure out how to pass the correct looped value from main.php within the div, back to the AJAX code on index.php
Can anyone help me with this?
Thanks,
Dustin
Instead of storing the id in the input, just pass it as an argument to the function:
function ajaxDelCcode(delccode) { ...
<input type='button' onclick='ajaxDelCcode(\"".$news_gen_id."\")' value='Delete' />
Also, I'd swap the quotes if I were you. Or better yet, instead of using echo, break the PHP code and just write HTML:
<? ... ?><input type="button" onclick="ajaxDelCcode('<?= $news_gen_id ?>')" value="Delete" /><? ... ?>
What does the code you use to delete look like? Is it in the same php file as the form you posted above? If so, is the form getting submitted to itself accidentally? Like perhaps when a user presses enter while on an input type=text control? I understand that you want to do this by ajax but I am suspecting that the form is your problem.
Seconding the jQuery comment.
Here try this
1) add jquery to your document.
<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
2) give your inputs name attributes
<input type='hidden' name='delcode' id='delccode' value='".$news_gen_id."'>
<input type='hidden' name='deledit' id='deledit' value='".$edit."'>
3) Use a function something like this instead of all that code above
function ajaxDelCcode() {
$.ajax({
url: "main.php",
type: "GET",
dataType: "text",
data: $("#myDelForm").serialize(),
success: function(rText) {
$("#ajaxMain2").text(rText);
}
});
}

ajaxComplete/ajaxStop/ajaxSuccess not firing

I appreciate any and all help. I am a beginner with little jQuery/AJAX experience and I have been going crazy trying to figure out why I can't figure this out.
I'm writing a Facebook page application that has the user grant permissions and upload a video to the page. All of this works fine and dandy. This is not so much a Facebook API related issue as it is an ajax issue (at least I think).
Basically, I am trying to gain control of the page IN SOME WAY after the user uploads a video. I am using the [malsup jQuery Form Plugin][1] to have the resulting page (which is a page on Facebook displaying returned JSON values) load in a hidden iframe.
I am able to get ajaxStart to fire, and I've tested this by having it change the background color or print an alert message when I click "Upload". However, when the upload completes (and it does complete successfully), NOTHING ELSE HAPPENS. The returned JSON values load in the hidden iframe and the page sits there. I have tried getting ajaxComplete, ajaxStop and ajaxSuccess to fire, but none of them do for whatever reason.
So overall, here is what I am trying to accomplish:
- I want to redirect the user or make some hidden content appear after the file upload completes. I don't even care if there's errors. I just need SOMETHING to happen.
- I am using the jQuery Form Plugin because I am not unfortunately not advanced enough to figure out how to use that value and do something with it, but if anyone can steer me in the right direction, that would be appreciated.
And finally, here is my code:
<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6/jquery.js"></script>
<script type="text/javascript" src="http://malsup.github.com/jquery.form.js"></script>
<script type="text/javascript">
// prepare the form when the DOM is ready
$(document).ready(function() {
var options = {
target: '#output2', // target element(s) to be updated with server response
iframeTarget: '#output2',
beforeSubmit: showRequest, // pre-submit callback
success: showResponse // post-submit callback
};
// bind form using 'ajaxForm'
$('#theform').ajaxForm(options);
});
// pre-submit callback
function showRequest(formData, jqForm, options) {
return true;
}
// post-submit callback
function showResponse(responseText, statusText, xhr, $form) {
alert(responseText);
}
</script>
<script type="text/javascript">
jQuery().ready(function(){
$('body').ajaxStart(function() {
$(this).css("background-color","red");
});
$('body').ajaxSend(function() {
$(this).css("background-color","blue");
});
$('body').ajaxComplete(function() {
$(this).css("background-color","green");
});
$('body').ajaxStop(function() {
$(this).css("background-color","purple");
});
});
</script>
</head>
<body>
<?php
$app_id = "xxxxxxx";
$app_secret = "xxxxx";
$my_url = "xxxxxx";
$video_title = "xxxxxxxxx";
$video_desc = "xxxxxxxxx";
$page_id = "xxxxxxxx";
$code = $_REQUEST["code"];
if(empty($code)) {
// Get permission from the user to publish to their page.
$dialog_url = "http://www.facebook.com/dialog/oauth?client_id="
. $app_id . "&redirect_uri=" . urlencode($my_url)
. "&display=popup&scope=email,publish_stream,manage_pages";
$current_url = (!empty($_SERVER['HTTPS'])) ? "https://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'] : "http://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
if ($current_url != $dialog_url)
{
echo('<script>window.location ="' . $dialog_url . '";</script>');
}
} else {
// Get access token for the user, so we can GET /me/accounts
$token_url = "https://graph.facebook.com/oauth/access_token?client_id="
. $app_id . "&redirect_uri=" . urlencode($my_url)
. "&client_secret=" . $app_secret
. "&code=" . $code;
$access_token = file_get_contents($token_url);
$accounts_url = "https://graph.facebook.com/me/accounts?" . $access_token;
$response = file_get_contents($accounts_url);
// Parse the return value and get the array of accounts we have
// access to. This is returned in the data[] array.
$resp_obj = json_decode($response,true);
$accounts = $resp_obj['data'];
// Find the access token for the page to which we want to post the video.
foreach($accounts as $account) {
if($account['id'] == $page_id) {
$access_token = $account['access_token'];
break;
}
}
// Using the page access token from above, create the POST action
// that our form will use to upload the video.
$post_url = "https://graph-video.facebook.com/" . $page_id . "/videos?"
. "title=" . $video_title. "&description=" . $video_desc
. "&access_token=". $access_token;
// Create a simple form
echo '<form action=" '.$post_url.' " method="POST" enctype="multipart/form-data" id="theform">';
echo 'Please choose a file:';
echo '<input name="file" type="file">';
echo '<input type="submit" value="Upload" id="button-upload" />';
echo '</form>';
}
?>
<iframe id="output2" name="output2"></iframe>
</body></html>
Thank you for your help!!
It seams you are getting an Ajax Error. I don't see any error handler in your code. Could you try to add an error handler as follows
<script>
$(document).ready(function(){
$(document).ajaxError(function(e, jqxhr, settings, exception) {
alert(exception);
})
})
</script>
I have played around with file uploads, and there are a complicated beast because of all the security that browsers have for protecting users file systems and whatnot.
On to your problem, I think that there is a good chance that your AjaxForm jQuery plugin doesn't connect properly to the global Ajax state for Jquery. Even if it did, I would say that tapping into the global Ajax state is a bad design. If you add any other ajax requests to this page, then your ajaxComplete, ajaxStop, etc. functions are going to start getting called.
Your better approach is to use the callbacks provided by the AjaxForm plugin. Lets focus on this first part of your code.
Does this work?
success: showResponse // post-submit callback
...
// post-submit callback
function showResponse(responseText, statusText, xhr, $form) {
alert(responseText);
}
If so, could you replace this:
$('body').ajaxComplete(function() {
$(this).css("background-color","green");
});
With this:
function showResponse(responseText, statusText, xhr, $form) {
$(this).css("background-color","green");
}
I believe that using the success: callback is the intended use of the AjaxForm plugin.
The jquery ajaxSend or ajaxStart throws some kind of an error and the document does not execute ajaxComplete. I tried to fix the bug for quite a while and was only able to find a workaround:
function hideAjaxIndicator() {
$('#ajax-indicator').hide();
}
$(document).ready(function () {
setTimeout(hideAjaxIndicator, 1000);
});
You can add this to .js file.

Update the content of a div via AJAX with jQuery when they're new events

I am doing a match "live timing" where an administrator sends to a database new inputs like: "Team A scores! 1-0". This is shown in a public website inside a <div /> and I want to get the new inputs and print it. I've never done something similar and I don't know what is the way to go.
I also have some doubts:
It's posible that the server sends the content to a X browser? So do the browser will only be on "idle"?
It's possible to only refresh when the user is active on the browser? Like Facebook does, if you're not present on the browser or moving your mouse over you don't get updates.
It's possible to append only to the <div /> the new items and not refresh all of it?
Thank you in advance!
You can use the ajax methods like this one:
$.getJSON('ajax/test.json', function(data) {
$('.result').html($('.result').html()+'<p>' + data.foo + '</p>'
+ '<p>' + data.baz[1] + '</p>');
});
or:
$.ajax({ url: "test.html", context: document.body, success: function(){
.......................................
}});
With a setTimeout call:
(function() {
$(document).ready(function() {update();});
function update() {
$.getJSON(.................);
setTimeout(update, 3000); }
}
)();
Then you could bind a mouseover event to the div that wraps your web, that would force an ajax call. You should use a control variable to know when the call is processing, so no to duplicate it.

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