I am working on a web part that must display some information in a modal box. Having worked with jQuery UI in the past and appreciating its simplicity and acceptance in the .NET world, I am trying to figure out what is the recommended approach to integrate the library via the web part. There are a lot of articles on the web, but having bounced from one to another in search of succinct instructions, I reached SO somewhat exhausted!
Here are my specific constraints:
I don't want to add jQuery and jQuery UI to the master page.
I don't want to use a CEWP to add the libraries to the page, since there are a good number of existing web part pages that will use the web part I am developing.
Whatever mechanism I use to add the libraries to a page, I want to make sure they don't conflict with an already added jQuery to that page. For instance, if I add two instances of this custom web part, the second one should ideally detect that jQuery has already been added to the page and must not be added again.
Using Designer is not at all an option (I just brought this up, even though it is most likely not an option).
Hopefully this does not sound too off-topic, but I need to add a jqGrid inside this modal box; I am considering a simpler approach such as using a combination of an SP application page + IFRAME.
I hope someone can give me step by step instructions to get started. That is tantamount to winning the lottery, at this point :-) Thank you!
To dynamically add javascript to a web page, you can do something like this:
var jQscript = document.createElement('script');
jQscript.type = 'text/javascript';
jQscript.src = '//ajax.aspnetcdn.com/ajax/jQuery/jquery-1.9.1.min.js';
if (typeof (jQuery) == 'undefined') //you can use !jQuery.ui for jQuery UI
document.getElementsByTagName('head')[0].appendChild(jQscript);
//make sure jQuery is fully loaded before trying to use it
For making sure it doesn't wreck anything else in the page, see jQuery.noConflict().
If you add the jQuery and jQueryUI scripts to the style library you could use RegisterClientScriptInclude.
// Define the name, type and url of the client script on the page.
String csname = "jQuery";
String csurl = "/Style Library/Scripts/jquery-2.0.3.min.js";
Type cstype = this.GetType();
// Get a ClientScriptManager reference from the Page class.
ClientScriptManager cs = Page.ClientScript;
// Check to see if the include script exists already.
if (!cs.IsClientScriptIncludeRegistered(cstype, csname))
{
cs.RegisterClientScriptInclude(cstype, csname, csurl);
}
Do the same again for jQueryUI replacing the references to jQuery as appropriate.
Related
I'm needing to load JS code on many different websites with different developer's code, and I want to load in jQuery into their site to manipulate the DOM. The only problem is they may or may not have jQuery already loaded on the page, and I don't want to conflict with that.
A lot of answers deal with checking if jQuery is already loaded on the page, or adding callbacks to when the entire dom is loaded. I don't want to go that approach, instead I want to know if I can directly load jQuery in as it's own variable which is completely isolated, so that I can use it directly without conflicting with whatever is outside.
This includes the fact that they may be using old, specific versions of jQuery that I can't go overwriting with my newer version. I really just want a complete isolated instance.
(function() {
// load jQuery in isolation and call it "xxx"
var divs = xxx('body').find('div');
})();
I also need to do this FROM JS itself, not by editing html (so I can't add jquery script tag in their HTML, i want to load it asyncronously with a callback)
You might try this approach:
(function(xxx) { // add xxx as a paramters
var divs = xxx('body').find('div');
})(jQuery); // Add jQuery as a value here.
As mentioned in other answers. You can check if jQuery is loaded using window.jQuery. And to check the version number you can use jQuery.fn.jquery.
I still however not sure what you mean by isolation. jQuery loads into window object which is global.
You might want to use another library like Zepto which has similar syntax to jQuery, or you can use vanilla JavaScript. See this link http://youmightnotneedjquery.com/
You could do this ...
if(!window.jQuery)
{
// load jquery here
}
Before you load your script. Declare no conflict.
Then you can load your script.
After that is loaded, do ...
var myJq = jQuery.noConflict();
You can access your library using myJq.
newbie question.
I've read some of the W3Schools, I also read a lot from other sources on the internet, however I can't find what I need, and I'm sure it's quite simple to you.
I'm using ASP.Net, and I want to add to my website, multiple items, which every item hold a picture, and some other information, including links. I'm pretty sure I don't need to write the code for every item in the HTML source, and I don't know exactly how to implement my this.
The basic idea is that my items will be imported from a Database that I create in visual studio, and I want to style my webpage so they would appear in a certain formation, I thought I might need to use Javascript or CSS for this, hope I'm not mistaken.
Javascript isn't some sort of magician that will render all your stuff on its own. However, you can use it to attach a template to every of your items.
What you have to do is :
Create a base HTML template for 1 of your item that can be applied to all of them
Create a Javascript function that will attach thoses CSS classes and HTML attributes to every element out of your DB (or you could use a templating frameork .. since there's a lot of them I'll let you look for it on Google. It's pretty easy to use)
On page load or whatever event you want to bind on, you call your function which will attach the CSS and HTML to every element out of your DB and will render it on your page
Enjoy what you've done.
I hope this helps. Good luck ! ;)
As I know that in JQuery Mobile, every page changing is equivalent to create new "page" div, Can we just change a portion in the "content" of the page, something like subpage?
jQuery Mobile doesn't require you to manage pages by creating additional div element in the same HTML file - you can do it perfectly fine in a different HTML file and make a transition to it (perhaps with data-prefetch attribute set) using <a>.
Nothing prevents you from writing a jQuery plug-in, jQuery UI plug-in or (scary though, I know) pure JavaScript that will alter the contents of the DOM element dynamically and manage pages loading according to data received from server - with necessary calls to things of the listview('refresh') ilk - to ensure proper styling.
With that said you have to ask yourself two things:
Why do you need to do it? Can't you manage by pre-creating the page using jQuery Mobile paradigm and just retrieving and inserting the data into the new page?
What will the performance implication (if any) will be, if I have to perform DOM manipulations on every 'page transition'?
As a side note - jQuery Mobile provides you with methods that allow for page manipulation:
$.mobile.changePage and $.mobile.loadPage that you can use (look at pageContainer option).
See API docs here
I am trying to use right now a jQueryMobile plugin for subpages: https://github.com/ToddThomson/jQuery-Mobile-Subpage-Widget
I didn't make it work yet but i think it should work :).
I have seen many questions raised around PartialViews and Javascript: the problem is a PartialView that requires Javascript, e.g. a view that renders a jqGrid:
The partial View needs a <div id="myGrid"></div>
and then some script:
<script>
$(document).ready(function(){
$('#myGrid').jqGrid( { // config params go here
});
}
</script>
The issue is how to include the PartialView without littering the page with inline tags and multiple $(document).ready tags.
We would also like to club the results from multiple RenderPartial calls into a single document.Ready() call.
And lastly we have the issue of the Javascript library files such as JQuery and JQGrid.js which should ideally be included at the bottom of the page (right before the $.ready block) and ideally only included when the appropriate PartialViews are used on the page.
In scouring the WWW it does not appear that anyone has solved this issue. A potential way might be to implement a custom View Engine. I was wondering if anyone had any alternative suggestions I may have missed?
This is a good question and it is something my team struggled with when JQuery was first released. One colleague wrote a page base class that combined all of the document ready calls into one, but it was a complete waste of time and our client's money.
There is no need to combine the $(document).ready() calls into one as they will all be called, one after the other in the order that they appear on the page. this is due to the multi-cast delegate nature of the method and it won't have a significant affect on performance. You might find your page slightly more maintainable, but maintainability is seldom an issue with jQuery as it has such concise syntax.
Could you expand on the reasons for wanting to combine them? I find a lot of developers are perfectionists and want their markup to be absolutely perfect. Rather, I find that when it is good enough for the client, when it performs adequately and displays properly, then my time is better spent delivering the next requirement. I have wasted a lot of time in the past formatting HTML that no-one will ever look at.
Any script that you want to appear at the bottom of the page should go inside the ClientScriptManager.RegisterStartupScript Method as it renders at the bottom of the page.
http://msdn.microsoft.com/en-us/library/z9h4dk8y.aspx
Edit Just noticed that your question was specific to ASP.NET MVC. My answer is more of an ASP.NET answer but in terms of the rendered html, most of my comments are still relevant. Multiple document.ready functions are not a problem.
The standard jQuery approach is to write a single script that will add behaviour to multiple elements. So, add a class to the divs that you want to contain a grid and call a function on each one:
<script language="text/javascript">
$(document).ready(function(){
$('.myGridClass').each(function(){
$(this).jqGrid( {
// config params can be determined from
//attributes added to the div element
var url = $(this).attr("data-url");
});
});
}
</script>
You only need to add this script once on your page and in your partial views you just have:
<div class="myGridClass" data-url="http://whatever-url-to-be-used"></div>
Notice the data-url attribute. This is HTML5 syntax, which will fail HTML 4 validation. It will still work in HTML 4 browsers. It only matters if you have to run your pages through html validators. And I can see you already know about HTML5
Not pretty but as regards your last point can you not send the appropriate tags as a ViewData dictionary in the action that returns the partial?
Okay i know that it's important for your website to work fine with javascript disabled.
In my opinion one way to start thinking about how to design such websites is to detect javascript at the homepage and if it's not enabled redirect to another version of website that does not javascript code and works with pure html (like gmail)
Another method that i have in mind is that for example think of a X (close button) on a dialog box on a webpage. What if pressing the X without any javascript interference lead to sending a request to the server and in the server side we hide that dialog next time we are rendering the page, And also we bind a javascript function to onclick of the link and in case of the javascript enabled it will hide the dialog instantly.
What do you think of this? How would you design a website to support both?
One way to deal with this is to :
First, create the site, without any javascript
Then, when every works, add javascript enhancements where suitable
This way, if JS is disabled, the "first" version of the site still works.
You can do exactly the same with CSS, naturally -- there is even one "CSS Naked Day" each day, showing what websites look like without CSS ^^
One example ?
You have a standard HTML form, that POSTs data to your server when submitted, and the re-creation of the page by the server displays a message like "thanks for subscriving"
You then add some JS + Ajax stuff : instead of reloading the whole page while submitting the form, you do an Ajax request, that only send the data ; and, in return, it displays "thanks for subscribing" without reloading the page
In this case, if javascript is disabled, the first "standard" way of doing things still works.
This is (part of) what is called Progressive enhancement
The usual method is what's called progressive enhancement.
Basically you take a simple HTML website, with regular forms.
The next enhancement is CSS - you make it look good.
Then you can enhance it further with Javascript - you can add or remove elements, add effects and so on.
The basic HTML is always there for old browsers (or those with script blockers, for example).
For example a form to post a comment might look like this:
<form action="post-comment.php" method="post" id="myForm">
<input type="text" name="comment">
</form>
Then you can enhance it with javascript to make it AJAXy
$('#myForm').submit(...);
Ideally the AJAX callback should use the same code as post-comment.php - either by calling the same file or via include, then you don't have to duplicate code.
In terms, it is not important to make your site work with JavaScript disabled. People who disable JavaScript are people who want to hack bugs into your site, they don't deserve to navigate it correctly. Don't waste your efforts with them. Everybody know the Web is unsurfable without JavaScript.
The only thing you have to be careful is about your forms: Don't ever trust filters in JavaScript, Always filter it again on server-side, ALWAYS!
Use Progressive Enhancement, study jquery to understand it. It takes some time till you get your head around it. For example your idea:
to detect javascript at the homepage
and if it's not enabled redirect to
another version of website that does
not javascript code and works with
pure html
how would you detect if javascript is disabled? not with javascript, obivously...
you're thinking the wrong way round: the most basic version has to be the default version, and then, if you detect more advanced capabilities, you can use them.
Try to avoid separate versions for different bowsers/capabilities for as long as you can. It's so much work to keep all versions in sync and up-do-date.
Some good ressources to get you started:
Understanding Progressive Enhancement
Progressive Enhancement with JavaScript
Test-Driven Progressive Enhancement
The best way is to design a page that works adequately without JS. Then add a <script> block at the bottom of the <body> section with code like this:
window.onload = function() {
// Do DOM manipulations to add JS functionality here. For instance...
document.getElementById('someInputField').onchange = function() {
// Do stuff here that you can't do in HTML, like on-the-fly validation
}
}
Study the jQuery examples. They show lots of things like this. This is called "unobtrusive JavaScript". Google for that to find more examples.
EDIT: The jQuery version of the above is:
$(document).ready(function() {
// Do DOM manipulations to add JS functionality here. For instance...
$('#someInputField').change(function() {
// Do stuff here that you can't do in HTML, like on-the-fly validation
});
});
I added this just to show the lower verbosity of jQuery vs. standard DOM manipulation. There is a minor difference between window.onload and document.ready, discussed in the jQuery docs and tutorials.
What you're aiming for is progressive enhancement. I'd go about this by first designing the site without the JavaScript and, once it works, start adding your JavaScript events via a library such as jQuery so that the behaviour of the site is completely separate from the presentation. This way you can provide a higher level of functionality and polish for those who have JavaScript enabled in their browsers and those who don't.