php/jQuery/ajax request hangs preventing further user interaction
On my localhost I don't seem to have the problem but on a live server at times when performing an ajax request that has some php querying the database, the ajax query will hang and the spinner/loader that blocks the UI will just get stuck in some infinite loop. This is obviously not good for the customer and not good for business. What is the best way to prevent this/troubleshoot this?
Scott Fell
Can you either provide a url for us to look at (make sure there is no private data) or use your browser dev tools by clicking on the f12 key. Then click on the Network tab and also select XHR. Once done, make your ajax call on the page and you can view the ajax reponse by clicking on the page that comes up in dev tools. That will give you a clue. Also in the Dev tools you can view the Console tab and see if there are any js errors that may prevent something from firing. A missing file is possible or even a js error.
ASKER
Thanks, Scott. I would rather not provide the URL at this point. I know that isn't super helpful to anyone viewing this question. I went to the network tab in google chrome but didn't see the XHR option. However, I actually remembered now that I have 2 ajax calls that are performed when the button is clicked.
Anyway, which info from the network tab do you want me to paste here? There is General, Response headers and Request headers.
Anyway, which info from the network tab do you want me to paste here? There is General, Response headers and Request headers.
See if this helps - Clicking on Network and filtering by clicking on XHR tab
Clicking on one of the files and viewing response
Viewing the response will show any errors on the page you are posting to. You can also try and create a sample form and just post directly to the page that is processing your ajax and get the information there. You may need to turn on errors.
Also remember to check the Applications tab for any js errors too.
Clicking on one of the files and viewing response
Viewing the response will show any errors on the page you are posting to. You can also try and create a sample form and just post directly to the page that is processing your ajax and get the information there. You may need to turn on errors.
Also remember to check the Applications tab for any js errors too.
ASKER
Thanks, Scott. I don't see that option on my browser (Chrome on Mac) but I did find those tabs like in your screenshot.
Is that where I should look when the page hangs obviously because when it is working I just see this:
Is that where I should look when the page hangs obviously because when it is working I just see this:
{"success":true,"message":"Product added to cart."}
The mac version will be different https://developers.google.com/web/tools/chrome-devtools/shortcuts try Command+Option+I.
In that area where you see your json data is where you may see the error too.
In that area where you see your json data is where you may see the error too.
ASKER
Thanks Scott, it seems like maybe it is getting stuck at the line 'beforeSend'. I don't get any errors in console so perhaps it could be the blockUI? I am using blockUI to show a spinner while the ajax request is meant to be happening like this:
I created a function called blockCartUI(),
Here is the blockUI code:
$.ajax({
url: url + '/CartAjax/AddToCart',
type: 'POST',
dataType: 'json',
data: {prod_id: prod_id, outlet_id: outlet_id},
beforeSend: function () {
blockCartUi();
},
})
//.done()I created a function called blockCartUI(),
function blockCartUi() {
$.blockUI({
message: '<div class="blockuispinner"></div>',
overlayCSS: {
backgroundColor: '#efefef',
opacity: 0.6,
cursor: 'wait'
},
});
}Here is the blockUI code:
/*!
* jQuery blockUI plugin
* Version 2.70.0-2014.11.23
* Requires jQuery v1.7 or later
*
* Examples at: http://malsup.com/jquery/block/
* Copyright (c) 2007-2013 M. Alsup
* Dual licensed under the MIT and GPL licenses:
* http://www.opensource.org/licenses/mit-license.php
* http://www.gnu.org/licenses/gpl.html
*
* Thanks to Amir-Hossein Sobhi for some excellent contributions!
*/
;(function() {
/*jshint eqeqeq:false curly:false latedef:false */
"use strict";
function setup($) {
$.fn._fadeIn = $.fn.fadeIn;
var noOp = $.noop || function() {};
// this bit is to ensure we don't call setExpression when we shouldn't (with extra muscle to handle
// confusing userAgent strings on Vista)
var msie = /MSIE/.test(navigator.userAgent);
var ie6 = /MSIE 6.0/.test(navigator.userAgent) && ! /MSIE 8.0/.test(navigator.userAgent);
var mode = document.documentMode || 0;
var setExpr = $.isFunction( document.createElement('div').style.setExpression );
// global $ methods for blocking/unblocking the entire page
$.blockUI = function(opts) { install(window, opts); };
$.unblockUI = function(opts) { remove(window, opts); };
// convenience method for quick growl-like notifications (http://www.google.com/search?q=growl)
$.growlUI = function(title, message, timeout, onClose) {
var $m = $('<div class="growlUI"></div>');
if (title) $m.append('<h1>'+title+'</h1>');
if (message) $m.append('<h2>'+message+'</h2>');
if (timeout === undefined) timeout = 3000;
// Added by konapun: Set timeout to 30 seconds if this growl is moused over, like normal toast notifications
var callBlock = function(opts) {
opts = opts || {};
$.blockUI({
message: $m,
fadeIn : typeof opts.fadeIn !== 'undefined' ? opts.fadeIn : 700,
fadeOut: typeof opts.fadeOut !== 'undefined' ? opts.fadeOut : 1000,
timeout: typeof opts.timeout !== 'undefined' ? opts.timeout : timeout,
centerY: false,
showOverlay: false,
onUnblock: onClose,
css: $.blockUI.defaults.growlCSS
});
};
callBlock();
var nonmousedOpacity = $m.css('opacity');
$m.mouseover(function() {
callBlock({
fadeIn: 0,
timeout: 30000
});
var displayBlock = $('.blockMsg');
displayBlock.stop(); // cancel fadeout if it has started
displayBlock.fadeTo(300, 1); // make it easier to read the message by removing transparency
}).mouseout(function() {
$('.blockMsg').fadeOut(1000);
});
// End konapun additions
};
// plugin method for blocking element content
$.fn.block = function(opts) {
if ( this[0] === window ) {
$.blockUI( opts );
return this;
}
var fullOpts = $.extend({}, $.blockUI.defaults, opts || {});
this.each(function() {
var $el = $(this);
if (fullOpts.ignoreIfBlocked && $el.data('blockUI.isBlocked'))
return;
$el.unblock({ fadeOut: 0 });
});
return this.each(function() {
if ($.css(this,'position') == 'static') {
this.style.position = 'relative';
$(this).data('blockUI.static', true);
}
this.style.zoom = 1; // force 'hasLayout' in ie
install(this, opts);
});
};
// plugin method for unblocking element content
$.fn.unblock = function(opts) {
if ( this[0] === window ) {
$.unblockUI( opts );
return this;
}
return this.each(function() {
remove(this, opts);
});
};
$.blockUI.version = 2.70; // 2nd generation blocking at no extra cost!
// override these in your code to change the default behavior and style
$.blockUI.defaults = {
// message displayed when blocking (use null for no message)
message: '<h1>Please wait...</h1>',
title: null, // title string; only used when theme == true
draggable: true, // only used when theme == true (requires jquery-ui.js to be loaded)
theme: false, // set to true to use with jQuery UI themes
// styles for the message when blocking; if you wish to disable
// these and use an external stylesheet then do this in your code:
// $.blockUI.defaults.css = {};
css: {
padding: 0,
margin: 0,
width: '30%',
top: '40%',
left: '35%',
textAlign: 'center',
// color: '#000',
// border: '3px solid #aaa',
// backgroundColor:'#fff',
cursor: 'wait'
},
// minimal style set used when themes are used
themedCSS: {
width: '30%',
top: '40%',
left: '35%'
},
// styles for the overlay
overlayCSS: {
backgroundColor: '#000',
opacity: 0.6,
cursor: 'wait'
},
// style to replace wait cursor before unblocking to correct issue
// of lingering wait cursor
cursorReset: 'default',
// styles applied when using $.growlUI
growlCSS: {
width: '350px',
top: '10px',
left: '',
right: '10px',
border: 'none',
padding: '5px',
opacity: 0.6,
cursor: 'default',
color: '#fff',
backgroundColor: '#000',
'-webkit-border-radius':'10px',
'-moz-border-radius': '10px',
'border-radius': '10px'
},
// IE issues: 'about:blank' fails on HTTPS and javascript:false is s-l-o-w
// (hat tip to Jorge H. N. de Vasconcelos)
/*jshint scripturl:true */
iframeSrc: /^https/i.test(window.location.href || '') ? 'javascript:false' : 'about:blank',
// force usage of iframe in non-IE browsers (handy for blocking applets)
forceIframe: false,
// z-index for the blocking overlay
baseZ: 1000,
// set these to true to have the message automatically centered
centerX: true, // <-- only effects element blocking (page block controlled via css above)
centerY: true,
// allow body element to be stetched in ie6; this makes blocking look better
// on "short" pages. disable if you wish to prevent changes to the body height
allowBodyStretch: true,
// enable if you want key and mouse events to be disabled for content that is blocked
bindEvents: true,
// be default blockUI will supress tab navigation from leaving blocking content
// (if bindEvents is true)
constrainTabKey: true,
// fadeIn time in millis; set to 0 to disable fadeIn on block
fadeIn: 200,
// fadeOut time in millis; set to 0 to disable fadeOut on unblock
fadeOut: 400,
// time in millis to wait before auto-unblocking; set to 0 to disable auto-unblock
timeout: 0,
// disable if you don't want to show the overlay
showOverlay: true,
// if true, focus will be placed in the first available input field when
// page blocking
focusInput: true,
// elements that can receive focus
focusableElements: ':input:enabled:visible',
// suppresses the use of overlay styles on FF/Linux (due to performance issues with opacity)
// no longer needed in 2012
// applyPlatformOpacityRules: true,
// callback method invoked when fadeIn has completed and blocking message is visible
onBlock: null,
// callback method invoked when unblocking has completed; the callback is
// passed the element that has been unblocked (which is the window object for page
// blocks) and the options that were passed to the unblock call:
// onUnblock(element, options)
onUnblock: null,
// callback method invoked when the overlay area is clicked.
// setting this will turn the cursor to a pointer, otherwise cursor defined in overlayCss will be used.
onOverlayClick: null,
// don't ask; if you really must know: http://groups.google.com/group/jquery-en/browse_thread/thread/36640a8730503595/2f6a79a77a78e493#2f6a79a77a78e493
quirksmodeOffsetHack: 4,
// class name of the message block
blockMsgClass: 'blockMsg',
// if it is already blocked, then ignore it (don't unblock and reblock)
ignoreIfBlocked: false
};
// private data and functions follow...
var pageBlock = null;
var pageBlockEls = [];
function install(el, opts) {
var css, themedCSS;
var full = (el == window);
var msg = (opts && opts.message !== undefined ? opts.message : undefined);
opts = $.extend({}, $.blockUI.defaults, opts || {});
if (opts.ignoreIfBlocked && $(el).data('blockUI.isBlocked'))
return;
opts.overlayCSS = $.extend({}, $.blockUI.defaults.overlayCSS, opts.overlayCSS || {});
css = $.extend({}, $.blockUI.defaults.css, opts.css || {});
if (opts.onOverlayClick)
opts.overlayCSS.cursor = 'pointer';
themedCSS = $.extend({}, $.blockUI.defaults.themedCSS, opts.themedCSS || {});
msg = msg === undefined ? opts.message : msg;
// remove the current block (if there is one)
if (full && pageBlock)
remove(window, {fadeOut:0});
// if an existing element is being used as the blocking content then we capture
// its current place in the DOM (and current display style) so we can restore
// it when we unblock
if (msg && typeof msg != 'string' && (msg.parentNode || msg.jquery)) {
var node = msg.jquery ? msg[0] : msg;
var data = {};
$(el).data('blockUI.history', data);
data.el = node;
data.parent = node.parentNode;
data.display = node.style.display;
data.position = node.style.position;
if (data.parent)
data.parent.removeChild(node);
}
$(el).data('blockUI.onUnblock', opts.onUnblock);
var z = opts.baseZ;
// blockUI uses 3 layers for blocking, for simplicity they are all used on every platform;
// layer1 is the iframe layer which is used to supress bleed through of underlying content
// layer2 is the overlay layer which has opacity and a wait cursor (by default)
// layer3 is the message content that is displayed while blocking
var lyr1, lyr2, lyr3, s;
if (msie || opts.forceIframe)
lyr1 = $('<iframe class="blockUI" style="z-index:'+ (z++) +';display:none;border:none;margin:0;padding:0;position:absolute;width:100%;height:100%;top:0;left:0" src="'+opts.iframeSrc+'"></iframe>');
else
lyr1 = $('<div class="blockUI" style="display:none"></div>');
if (opts.theme)
lyr2 = $('<div class="blockUI blockOverlay ui-widget-overlay" style="z-index:'+ (z++) +';display:none"></div>');
else
lyr2 = $('<div class="blockUI blockOverlay" style="z-index:'+ (z++) +';display:none;border:none;margin:0;padding:0;width:100%;height:100%;top:0;left:0"></div>');
if (opts.theme && full) {
s = '<div class="blockUI ' + opts.blockMsgClass + ' blockPage ui-dialog ui-widget ui-corner-all" style="z-index:'+(z+10)+';display:none;position:fixed">';
if ( opts.title ) {
s += '<div class="ui-widget-header ui-dialog-titlebar ui-corner-all blockTitle">'+(opts.title || ' ')+'</div>';
}
s += '<div class="ui-widget-content ui-dialog-content"></div>';
s += '</div>';
}
else if (opts.theme) {
s = '<div class="blockUI ' + opts.blockMsgClass + ' blockElement ui-dialog ui-widget ui-corner-all" style="z-index:'+(z+10)+';display:none;position:absolute">';
if ( opts.title ) {
s += '<div class="ui-widget-header ui-dialog-titlebar ui-corner-all blockTitle">'+(opts.title || ' ')+'</div>';
}
s += '<div class="ui-widget-content ui-dialog-content"></div>';
s += '</div>';
}
else if (full) {
s = '<div class="blockUI ' + opts.blockMsgClass + ' blockPage" style="z-index:'+(z+10)+';display:none;position:fixed"></div>';
}
else {
s = '<div class="blockUI ' + opts.blockMsgClass + ' blockElement" style="z-index:'+(z+10)+';display:none;position:absolute"></div>';
}
lyr3 = $(s);
// if we have a message, style it
if (msg) {
if (opts.theme) {
lyr3.css(themedCSS);
lyr3.addClass('ui-widget-content');
}
else
lyr3.css(css);
}
// style the overlay
if (!opts.theme /*&& (!opts.applyPlatformOpacityRules)*/)
lyr2.css(opts.overlayCSS);
lyr2.css('position', full ? 'fixed' : 'absolute');
// make iframe layer transparent in IE
if (msie || opts.forceIframe)
lyr1.css('opacity',0.0);
//$([lyr1[0],lyr2[0],lyr3[0]]).appendTo(full ? 'body' : el);
var layers = [lyr1,lyr2,lyr3], $par = full ? $('body') : $(el);
$.each(layers, function() {
this.appendTo($par);
});
if (opts.theme && opts.draggable && $.fn.draggable) {
lyr3.draggable({
handle: '.ui-dialog-titlebar',
cancel: 'li'
});
}
// ie7 must use absolute positioning in quirks mode and to account for activex issues (when scrolling)
var expr = setExpr && (!$.support.boxModel || $('object,embed', full ? null : el).length > 0);
if (ie6 || expr) {
// give body 100% height
if (full && opts.allowBodyStretch && $.support.boxModel)
$('html,body').css('height','100%');
// fix ie6 issue when blocked element has a border width
if ((ie6 || !$.support.boxModel) && !full) {
var t = sz(el,'borderTopWidth'), l = sz(el,'borderLeftWidth');
var fixT = t ? '(0 - '+t+')' : 0;
var fixL = l ? '(0 - '+l+')' : 0;
}
// simulate fixed position
$.each(layers, function(i,o) {
var s = o[0].style;
s.position = 'absolute';
if (i < 2) {
if (full)
s.setExpression('height','Math.max(document.body.scrollHeight, document.body.offsetHeight) - (jQuery.support.boxModel?0:'+opts.quirksmodeOffsetHack+') + "px"');
else
s.setExpression('height','this.parentNode.offsetHeight + "px"');
if (full)
s.setExpression('width','jQuery.support.boxModel && document.documentElement.clientWidth || document.body.clientWidth + "px"');
else
s.setExpression('width','this.parentNode.offsetWidth + "px"');
if (fixL) s.setExpression('left', fixL);
if (fixT) s.setExpression('top', fixT);
}
else if (opts.centerY) {
if (full) s.setExpression('top','(document.documentElement.clientHeight || document.body.clientHeight) / 2 - (this.offsetHeight / 2) + (blah = document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop) + "px"');
s.marginTop = 0;
}
else if (!opts.centerY && full) {
var top = (opts.css && opts.css.top) ? parseInt(opts.css.top, 10) : 0;
var expression = '((document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop) + '+top+') + "px"';
s.setExpression('top',expression);
}
});
}
// show the message
if (msg) {
if (opts.theme)
lyr3.find('.ui-widget-content').append(msg);
else
lyr3.append(msg);
if (msg.jquery || msg.nodeType)
$(msg).show();
}
if ((msie || opts.forceIframe) && opts.showOverlay)
lyr1.show(); // opacity is zero
if (opts.fadeIn) {
var cb = opts.onBlock ? opts.onBlock : noOp;
var cb1 = (opts.showOverlay && !msg) ? cb : noOp;
var cb2 = msg ? cb : noOp;
if (opts.showOverlay)
lyr2._fadeIn(opts.fadeIn, cb1);
if (msg)
lyr3._fadeIn(opts.fadeIn, cb2);
}
else {
if (opts.showOverlay)
lyr2.show();
if (msg)
lyr3.show();
if (opts.onBlock)
opts.onBlock.bind(lyr3)();
}
// bind key and mouse events
bind(1, el, opts);
if (full) {
pageBlock = lyr3[0];
pageBlockEls = $(opts.focusableElements,pageBlock);
if (opts.focusInput)
setTimeout(focus, 20);
}
else
center(lyr3[0], opts.centerX, opts.centerY);
if (opts.timeout) {
// auto-unblock
var to = setTimeout(function() {
if (full)
$.unblockUI(opts);
else
$(el).unblock(opts);
}, opts.timeout);
$(el).data('blockUI.timeout', to);
}
}
// remove the block
function remove(el, opts) {
var count;
var full = (el == window);
var $el = $(el);
var data = $el.data('blockUI.history');
var to = $el.data('blockUI.timeout');
if (to) {
clearTimeout(to);
$el.removeData('blockUI.timeout');
}
opts = $.extend({}, $.blockUI.defaults, opts || {});
bind(0, el, opts); // unbind events
if (opts.onUnblock === null) {
opts.onUnblock = $el.data('blockUI.onUnblock');
$el.removeData('blockUI.onUnblock');
}
var els;
if (full) // crazy selector to handle odd field errors in ie6/7
els = $('body').children().filter('.blockUI').add('body > .blockUI');
else
els = $el.find('>.blockUI');
// fix cursor issue
if ( opts.cursorReset ) {
if ( els.length > 1 )
els[1].style.cursor = opts.cursorReset;
if ( els.length > 2 )
els[2].style.cursor = opts.cursorReset;
}
if (full)
pageBlock = pageBlockEls = null;
if (opts.fadeOut) {
count = els.length;
els.stop().fadeOut(opts.fadeOut, function() {
if ( --count === 0)
reset(els,data,opts,el);
});
}
else
reset(els, data, opts, el);
}
// move blocking element back into the DOM where it started
function reset(els,data,opts,el) {
var $el = $(el);
if ( $el.data('blockUI.isBlocked') )
return;
els.each(function(i,o) {
// remove via DOM calls so we don't lose event handlers
if (this.parentNode)
this.parentNode.removeChild(this);
});
if (data && data.el) {
data.el.style.display = data.display;
data.el.style.position = data.position;
data.el.style.cursor = 'default'; // #59
if (data.parent)
data.parent.appendChild(data.el);
$el.removeData('blockUI.history');
}
if ($el.data('blockUI.static')) {
$el.css('position', 'static'); // #22
}
if (typeof opts.onUnblock == 'function')
opts.onUnblock(el,opts);
// fix issue in Safari 6 where block artifacts remain until reflow
var body = $(document.body), w = body.width(), cssW = body[0].style.width;
body.width(w-1).width(w);
body[0].style.width = cssW;
}
// bind/unbind the handler
function bind(b, el, opts) {
var full = el == window, $el = $(el);
// don't bother unbinding if there is nothing to unbind
if (!b && (full && !pageBlock || !full && !$el.data('blockUI.isBlocked')))
return;
$el.data('blockUI.isBlocked', b);
// don't bind events when overlay is not in use or if bindEvents is false
if (!full || !opts.bindEvents || (b && !opts.showOverlay))
return;
// bind anchors and inputs for mouse and key events
var events = 'mousedown mouseup keydown keypress keyup touchstart touchend touchmove';
if (b)
$(document).bind(events, opts, handler);
else
$(document).unbind(events, handler);
// former impl...
// var $e = $('a,:input');
// b ? $e.bind(events, opts, handler) : $e.unbind(events, handler);
}
// event handler to suppress keyboard/mouse events when blocking
function handler(e) {
// allow tab navigation (conditionally)
if (e.type === 'keydown' && e.keyCode && e.keyCode == 9) {
if (pageBlock && e.data.constrainTabKey) {
var els = pageBlockEls;
var fwd = !e.shiftKey && e.target === els[els.length-1];
var back = e.shiftKey && e.target === els[0];
if (fwd || back) {
setTimeout(function(){focus(back);},10);
return false;
}
}
}
var opts = e.data;
var target = $(e.target);
if (target.hasClass('blockOverlay') && opts.onOverlayClick)
opts.onOverlayClick(e);
// allow events within the message content
if (target.parents('div.' + opts.blockMsgClass).length > 0)
return true;
// allow events for content that is not being blocked
return target.parents().children().filter('div.blockUI').length === 0;
}
function focus(back) {
if (!pageBlockEls)
return;
var e = pageBlockEls[back===true ? pageBlockEls.length-1 : 0];
if (e)
e.focus();
}
function center(el, x, y) {
var p = el.parentNode, s = el.style;
var l = ((p.offsetWidth - el.offsetWidth)/2) - sz(p,'borderLeftWidth');
var t = ((p.offsetHeight - el.offsetHeight)/2) - sz(p,'borderTopWidth');
if (x) s.left = l > 0 ? (l+'px') : '0';
if (y) s.top = t > 0 ? (t+'px') : '0';
}
function sz(el, p) {
return parseInt($.css(el,p),10)||0;
}
}
/*global define:true */
if (typeof define === 'function' && define.amd && define.amd.jQuery) {
define(['jquery'], setup);
} else {
setup(jQuery);
}
})();
Comment out the before send function and test if you still get errors.
I wonder if your live database has bad data coming in. That may explain why it works locally and intermittently live.
I wonder if your live database has bad data coming in. That may explain why it works locally and intermittently live.
ASKER
Okay, will try that. But I still want the blockUI to work. So, would I just do this?
or would I instead do it when the button has been clicked before the ajax call?
$.ajax({
url: url + '/CartAjax/AddToCart',
type: 'POST',
dataType: 'json',
data: {prod_id: prod_id, outlet_id: outlet_id},
blockCartUi();
})
//.done()or would I instead do it when the button has been clicked before the ajax call?
No, try this
The idea is to eliminate this since you feel it is the issue. If you still have problems with this commented out, then you know that is not the issue. Otherwise, we can work on that.
$.ajax({
url: url + '/CartAjax/AddToCart',
type: 'POST',
dataType: 'json',
data: {prod_id: prod_id, outlet_id: outlet_id}
//beforeSend: function () {
//blockCartUi();
//},
})The idea is to eliminate this since you feel it is the issue. If you still have problems with this commented out, then you know that is not the issue. Otherwise, we can work on that.
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ASKER
Hi Scott, sorry for delayed response. I had something similar but it only disabled the button and showed a spinner on the button. I will have to play around to disable the entire page as I don't want the user to be able to click anywhere during processing. Perhaps I can disable the first div the whole body sits in. Thanks!
Line 19 of my example, any form element that has the class, "frm" will be disabled. If you already have a class for your form elements, you can use it or if a parent element has a class or id you can use that too.
<div id="form">
<form>
<input name="first">
<input name="last">
<button>Submit</button>
</form>
</div> $('#form input, #form button').prop('disabled', true); // ON SUBMIT, DISABLE