Trying to build a widget using jquery and javascript - javascript

I'm currently working on a widget using javascript and jquery. Now what I want to create a widget button that when clicked, will start a chat with the person whose id is associated with the widget. On the main website it's just a call to the function that does that but with the widget I don't really know how to do it since I can't call my function from another website.
I've read a few tutorials on creating jquery widgets but I didn't fully grasp them because it seems that what the tutorial was teaching was to retrieve data from the host server which isn't really my intention. Also they quoted the use of JSON which I don't also fully grasp as it seems that JSON is a way of displaying objects and strings.
Anyway I need some guidance on how to achieve this.
So far this is what I put down :
(function () {
var jQuery;
if (window.jQuery == undefined || window.jQuery.fn.jquery !== '1.8.1') {
var script_tag = document.createElement('script');
script_tag.setAttribute("type", "text/javascript");
script_tag.setAttribute("src", "http://ajax.googleapis.com/ajax/libs/jquery/1.8.1/jquery.min.js");
if (script_tag.readyState) {
script_tag.onreadystatechange = function () {
if (this.readyState == 'complete' || this.readyState == 'loaded') {
scriptLoadHandler();
}
};
} else {
script_tag.onload = scriptLoadHandler;
}
(document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script_tag);
} else {
jQuery = window.jQuery;
main();
}
function scriptLoadHandler() {
jQuery = window.jQuery.noConflict(true);
main();
}
function main() {
jQuery(document).ready(function ($) {
var homeURL = 'http://www.reflap.com/';
var css_link = $("<link>", {
rel: "stylesheet",
type: "text/css",
href: homeURL + "assets/widget.css"
});
var $container = ('#mywebsite-container');
css_link.appendTo('head');
$.getJSON(homeURL + 'assets/js/anonymous.js', function (response) {
$container.append(response.html);
});
});
}
})();
NEW EDIT
This is what I attempted before.
The function in question is call chat and it takes 3 parameters.
So my first widget looked like this
<script src="http://www.mydomain.com/chatter.js"></script><a href="#"
onclick="Chatter.chat('1','user', null)" id="chat-widget">Chat now</a>
But that doesn't work.

Related

loading jquery library from javascript getting error $ is not defined

I have loaded my jquery library in my plug in from javascript and getting an error $ is not defined if I call my plug in anonymous function from another javscript page
Following is my work
(function () {
// Localize jQuery variable
var jQuery;
/******** Load jQuery if not present *********/
if (window.jQuery === undefined || window.jQuery.fn.jquery !== '1.11.3') {
var script_tag = document.createElement('script');
script_tag.setAttribute("type", "text/javascript");
script_tag.setAttribute("src",
"https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js");
if (script_tag.readyState) {
script_tag.onreadystatechange = function () { // For old versions of IE
if (this.readyState == 'complete' || this.readyState == 'loaded') {
scriptLoadHandler();
}
};
} else {
script_tag.onload = scriptLoadHandler;
}
// Try to find the head, otherwise default to the documentElement
(document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script_tag);
} else {
// The jQuery version on the window is the one we want to use
jQuery = window.jQuery;
main();
}
/******** Called once jQuery has loaded ******/
function scriptLoadHandler() {
// Restore $ and window.jQuery to their previous values and store the
// new jQuery in our local jQuery variable
jQuery = window.jQuery.noConflict();
// Call our main function
main();
}
/******** Our main function ********/
function main() {
// Add some validation here to make sure UI is not loaded etc...
jQuery.getScript('http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.6/jquery-ui.min.js');
jQuery(document).ready(function ($) {
/******* Load CSS *******/
var css_link = $("<link>", {
rel: "stylesheet",
type: "text/css",
href: "StyleSheet.css"
});
css_link.appendTo('head');
//loading plug in
"use strict";
$.fn.myplugin = function (options) {
var settings = $.extend({
//default
isstatic: false
});
var options = $.extend(settings, options);
var images = ['http://www.example1.com'/1.png, 'http://www.example2.com/final.gif'];
//Iterate over the current set of matched elements
return this.each(function () {
var obj = $('.div2');
obj.hide();
$(this).show();
$(this).click(function () {
obj.toggle("slow");
if (options.isstatic) {
$(".image-class").attr("src", images[0]);
options.isstatic = false;
}
else {
$(".image-class").attr("src", images[1]);
options.isstatic = true;
}
});
});
return options.isstatic = false;
}
});
}
})();
I am calling it using another file.js
$(document).ready(function () {
$('#mydiv').myplugin();
});
I am getting an error here $ is no defined how to remove this error may b I have done something wrong with jQuery variable or $ in javascript file
I guess you need jquery for further scripts in your page or for your plugin to run, so jquery reference should be the first one in the head, could you try replacing the part of your code
( document.getElementsByTagName("head")[0] || document.documentElement ).appendChild(script_tag)
with
var head=( document.getElementsByTagName("head")[0] || document.documentElement ); head.insertBefore(script_tag,head.firstChild);

how to create a reusable javascript web-app from my HTML CSS and JS files

i have a working HTML file with CSS and JS files i want to create a web app with this.
i don't have any experience or idea how to create a webapp from what i have.
my code dosen't need any interaction with the server.
i have found this guide from this site
(function() {
// Localize jQuery variable
var jQuery;
/******** Load jQuery if not present *********/
if (window.jQuery === undefined || window.jQuery.fn.jquery !== '1.4.2') {
var script_tag = document.createElement('script');
script_tag.setAttribute("type","text/javascript");
script_tag.setAttribute("src",
"http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js");
if (script_tag.readyState) {
script_tag.onreadystatechange = function () { // For old versions of IE
if (this.readyState == 'complete' || this.readyState == 'loaded') {
scriptLoadHandler();
}
};
} else {
script_tag.onload = scriptLoadHandler;
}
// Try to find the head, otherwise default to the documentElement
(document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script_tag);
} else {
// The jQuery version on the window is the one we want to use
jQuery = window.jQuery;
main();
}
/******** Called once jQuery has loaded ******/
function scriptLoadHandler() {
// Restore $ and window.jQuery to their previous values and store the
// new jQuery in our local jQuery variable
jQuery = window.jQuery.noConflict(true);
// Call our main function
main();
}
/******** Our main function ********/
function main() {
jQuery(document).ready(function($) {
/******* Load CSS *******/
var css_link = $("<link>", {
rel: "stylesheet",
type: "text/css",
href: "style.css"
});
css_link.appendTo('head');
/******* Load HTML *******/
var jsonp_url = "http://al.smeuh.org/cgi-bin/webwidget_tutorial.py?callback=?";
$.getJSON(jsonp_url, function(data) {
$('#example-widget-container').html("This data comes from another server: " + data.html);
});
});
}
})(); // We call our anonymous function immediately
1.) i understood till loading CSS but i did not get what the code is doing for loading a HTML file.
2.) is it possible to do a webapp with what i have and how..?
3.) i know css html js jq.......... is it important to know ajax or anything else for creating a web app.
thank you.
I'm not sure if I understand your question, but maybe if I try to describe what this script is doing, it will help you?
Basically, this script is (somewhat clumsily IMO) first loading jQuery, and then loading a stylesheet style.css and finally retrieving data from http://al.smeuh.org/cgi-bin/webwidget_tutorial.py?callback=?. It assumes that you have a document element with the id "example-widget-container", which is where it will inject the html received from the JSON call.
If you clarify what exactly you're asking, then maybe I or someone else can help you some more.

$.getScript gives Unexpected token

I found some code online that helps me to provide widgets to my clients. My understanding of the full code below is that it first detects if jQuery is present otherwise loads it. As part of my widget I also want to ensure that fancybox is loaded because I am basically providing a button that onClicks loads an iframe in fancybox.
The particular area of interest is in which .getScript gives me an error Unexpected token .. I know that jQuery is already loaded because .getJSON below works.
Code:
var fancyboxScript = widgetURL + "fancybox/source/jquery.fancybox.pack.js?v=2.1.5");
$.getScript(fancyboxScript);
/******* Load HTML *******/
var jsonp_url = widgetURL + "widgetCall.php?callback=?";
$.getJSON(jsonp_url,'merchantID='+merchantID, function(data) {
$('#widget-container').html(data.html);
});
The full code is below:
(function() {
// Localize jQuery variable
var jQuery;
var widgetURL = "http://...mywidgetURL/...";
/******** Load jQuery if not present *********/
if (window.jQuery === undefined || window.jQuery.fn.jquery !== '1.4.2') {
var script_tag = document.createElement('script');
script_tag.setAttribute("type","text/javascript");
script_tag.setAttribute("src",
"http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js");
if (script_tag.readyState) {
script_tag.onreadystatechange = function () { // For old versions of IE
if (this.readyState == 'complete' || this.readyState == 'loaded') {
scriptLoadHandler();
}
};
} else {
script_tag.onload = scriptLoadHandler;
}
// Try to find the head, otherwise default to the documentElement
(document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script_tag);
} else {
// The jQuery version on the window is the one we want to use
jQuery = window.jQuery;
main();
}
/******** Called once jQuery has loaded ******/
function scriptLoadHandler() {
// Restore $ and window.jQuery to their previous values and store the
// new jQuery in our local jQuery variable
jQuery = window.jQuery.noConflict(true);
// Call our main function
main();
}
/******** Our main function ********/
function main() {
jQuery(document).ready(function($) {
/******* Load CSS *******/
var css_link = $("<link>", {
rel: "stylesheet",
type: "text/css",
href: widgetURL + "myCSS.css"
});
css_link.appendTo('head');
/******* Load FANCYBOX *******/
var fancy_link = $("<link>", {
rel: "stylesheet",
type: "text/css",
href: widgetURL + "fancybox/source/jquery.fancybox.css?v=2.1.5",
media: "screen"
});
fancy_link.appendTo('head');
var fancy2_link = $("<link>", {
rel: "stylesheet",
type: "text/css",
href: widgetURL + "fancybox/source/helpers/jquery.fancybox-thumbs.css?v=1.0.7",
media: "screen"
});
fancy2_link.appendTo('head');
var fancyboxScript = widgetURL + "fancybox/source/jquery.fancybox.pack.js?v=2.1.5");
$.getScript(fancyboxScript);
/******* Load HTML *******/
var jsonp_url = widgetURL + "widgetCall.php?callback=?";
$.getJSON(jsonp_url,'merchantID='+merchantID, function(data) {
$('#widget-container').html(data.html);
});
});
}
})(); // We call our anonymous function immediately
you have made small mistake in your code
var fancyboxScript = widgetURL + "fancybox/source/jquery.fancybox.pack.js?v=2.1.5"); //closing round brackets is the issue
$.getScript(fancyboxScript);
you have added a closing round brackets in the line above, hence the syntax error, just remove it and try, it should work as you intended.
Happy Coding:)
well this must be one of the stupidest mistakes on SO. But I hope it saves someone some time in future.
Basically I had an additional ) at the end of my fancyboxScript declaration.
var fancyboxScript = widgetURL + "fancybox/source/jquery.fancybox.pack.js?v=2.1.5");
should have just been
var fancyboxScript = widgetURL + "fancybox/source/jquery.fancybox.pack.js?v=2.1.5";

Unable to use jQuery with server-side Rails widget

I'm creating a widget, for which I have initialized jQuery like so:
# widget.js
(function() {
var jQuery;
var root_url = "<%= root_url%>";
if (window.jQuery === undefined || window.jQuery.fn.jquery !== '1.9.1') {
var jquery_script = document.createElement('script');
jquery_script.type = "text/javascript";
jquery_script.asyc = true;
jquery_script.src = "http://code.jquery.com/jquery-1.9.1.js";
if (jquery_script.readyState) {
script_tag.onreadystatechange = function () { // For old versions of IE
if (this.readyState == 'complete' || this.readyState == 'loaded') {
scriptLoadHandler();
}
};
} else { // Other browsers
jquery_script.onload = scriptLoadHandler;
}
var node = document.getElementsByTagName('script')[0];
node.parentNode.insertBefore(jquery_script, node);
} else {
jQuery = window.jQuery;
main();
}
function scriptLoadHandler() {
jQuery = window.jQuery.noConflict(true);
main();
}
function main() {
jQuery(document).ready(function($) {
// jQuery works great here!
// But not so much in rendered partials or in server-side JS actions
}
}
})();
If I make an ajax request to my server and respond with a JS action, I can't use jQuery in my action.js.erb file. It spits out the error $ is not a function.
Similarly, even rendering partials with jQuery scripts in them yields the same results.
I think I haven't set a global instance of jQuery, and if this is the case, I'm not sure how to do that. Perhaps I'm not supposed to?
How can I get around this problem?
This solution isn't what I was looking for but I was able to combine elements of the native JS widget with an iframe. Once I manipulate whatever elements I need to on the 3rd party site (as per my widget's functionality) I render a partial housing an iframe that lets me completely control the environment.

How to embed Javascript widget that depends on jQuery into an unknown environment

I'm developing a javascript widget that depends on jQuery. The widget may or may not be loaded onto a page that already has jQuery loaded. There are many problems that come up in this case...
If the web page does not have jQuery, I must load my own jQuery. There seems to be a delicate timing issue when doing this, however. For example, if my widget loads and executes before jQuery is finished loading and executing, I get a jQuery is not defined error.
If the web page does have jQuery, I can usually work with it. If the jQuery version is old, however, I would like to load my own. If I do load my own, however, I need to do it in such a way as to not stomp on their $ variable. If I set jQuery.noConflict() and any of their scripts depend on $, then I have just broken their page.
If the web page uses another javascript library (e.g. prototype), I needed to be sensitive of prototype's $ variable also.
Because of all of the above, it is seeming easier to not depend on jQuery. But before I go down that road, which will involve mostly rewriting my widget code, I wanted to ask for advice first.
The basic skeleton of my code, including the timing bug and sometimes $ bugs, follows:
<script type="text/javascript" charset="utf-8">
// <![CDATA
if (typeof jQuery === 'undefined') {
var head = document.getElementsByTagName('head')[0];
var script = document.createElement('script');
script.type = 'text/javascript';
script.src = '{{ URL }}/jquery.js';
head.appendChild(script);
}
// ]]>
</script>
<script type="text/javascript" src="{{ URL }}/widget.js"></script>
My widget has the following structure:
(function($) {
var mywidget = {
init: function() {
...
}
};
$(document).ready(function() {
mywidget.init();
});
})(jQuery);
If there are any pointers or resources for achieving a widget that can work in all the mentioned environments, they would be greatly appreciated.
After reviewing some answers and pointers, and finding some helpful jQuery hackers, I ended up with something like the following:
(function(window, document, version, callback) {
var j, d;
var loaded = false;
if (!(j = window.jQuery) || version > j.fn.jquery || callback(j, loaded)) {
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "/media/jquery.js";
script.onload = script.onreadystatechange = function() {
if (!loaded && (!(d = this.readyState) || d == "loaded" || d == "complete")) {
callback((j = window.jQuery).noConflict(1), loaded = true);
j(script).remove();
}
};
(document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script);
}
})(window, document, "1.3", function($, jquery_loaded) {
// Widget code here
});
This will load jQuery if it's not already loaded and encapsulates it in the callback so it doesn't conflict with a pre-existing jQuery on the page. It also checks that a minimum version is available or else loads a known version -- in this case, v1.3. It sends a boolean value to the callback (my widget) on whether or not jQuery was loaded in case there are any triggers needed to be made. And only after jQuery is loaded does it call my widget, passing jQuery into it.
See How to build a web widget (using jQuery) by Alex Marandon.
(function() {
// Localize jQuery variable
var jQuery;
/******** Load jQuery if not present *********/
if (window.jQuery === undefined || window.jQuery.fn.jquery !== '1.4.2') {
var script_tag = document.createElement('script');
script_tag.setAttribute("type","text/javascript");
script_tag.setAttribute("src",
"http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js");
if (script_tag.readyState) {
script_tag.onreadystatechange = function () { // For old versions of IE
if (this.readyState == 'complete' || this.readyState == 'loaded') {
scriptLoadHandler();
}
};
} else { // Other browsers
script_tag.onload = scriptLoadHandler;
}
// Try to find the head, otherwise default to the documentElement
(document.getElementsByTagName("head")[0] || document.documentElement).appendChild(script_tag);
} else {
// The jQuery version on the window is the one we want to use
jQuery = window.jQuery;
main();
}
/******** Called once jQuery has loaded ******/
function scriptLoadHandler() {
// Restore $ and window.jQuery to their previous values and store the
// new jQuery in our local jQuery variable
jQuery = window.jQuery.noConflict(true);
// Call our main function
main();
}
/******** Our main function ********/
function main() {
jQuery(document).ready(function($) {
// We can use jQuery 1.4.2 here
});
}
})(); // We call our anonymous function immediately
What if you also want to use some jQuery plugins? Is it safe to make yourself a single file with the minified versions of the plugins, and also load those, as below? (Loaded from S3, in this particular example.)
(function(window, document, version, callback) {
var j, d;
var loaded = false;
if (!(j = window.jQuery) || version > j.fn.jquery || callback(j, loaded)) {
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "http://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js";
script.onload = script.onreadystatechange = function() {
if (!loaded && (!(d = this.readyState) || d == "loaded" || d == "complete")) {
window.jQuery.getScript('http://mydomain.s3.amazonaws.com/assets/jquery-plugins.js', function() {
callback((j = window.jQuery).noConflict(1), loaded = true);
j(script).remove();
});
}
};
document.documentElement.childNodes[0].appendChild(script)
}
})(window, document, "1.5.2", function($, jquery_loaded) {
// widget code goes here
});
SEE Can I use multiple versions of jQuery on the same page?
Can you use document.write() to optionally add the jQuery script to the page? That should force jQuery to load synchronously. Try this:
<script type="text/javascript" charset="utf-8">
// <![CDATA
if (typeof jQuery === 'undefined') {
document.write('<script src="{{ URL }}/jquery.js"><' + '/script>');
}
// ]]>
</script>
<script type="text/javascript" src="{{ URL }}/widget.js"></script>
If you want to do the jQuery check inside your widget script then I believe the following works cross-browser:
(function() {
function your_call($) {
// your widget code goes here
}
if (typeof jQuery !== 'undefined') your_call(jQuery);
else {
var head = document.getElementsByTagName('head')[0];
var script = document.createElement('script');
script.type = 'text/javascript';
script.src = '{{ URL }}/jquery.js';
var onload = function() {
if (!script.readyState || script.readyState === "complete") your_call(jQuery);
}
if ("onreadystatechange" in script) script.onreadystatechange = onload;
else script.onload = onload;
head.appendChild(script);
}
})()
I know this is an old topic... but i got something faster that your hack.
Try in your widget
"init": function()
that will fix the trouble
I would download the jQuery source and modify the jQuery object to another (jQueryCustom).
And then find the instance that sets the $ symbol as a jQuery object and comment that routine.
I don't know how easy or difficult could that be, but I'd sure give it a try.
(Also, check your second option, as it is not bad, the site where the widget will be executing, might have a jQuery version older than the one you need).
EDIT: I just checked the source. You just have to replace jQuery with another string (jQcustom for example). Then, try commenting this line:
_$ = window.$
And you make reference to the custom jQuery like this:
jQcustom("#id").attr(...)

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