I am creating a UI, in which user can add / delete items (of similar layout).
It starts with one item and you can click 'add' to add more. The UI consists of several different types of items.
What I am doing currently is populating a single item item 1 ( of each type ) and on add event, I clone the item 1, replace the changes done by user in item 1 and append the clone to the container.
In simple words, instead of dynamically creating html with jQuery, I am cloning html of a div. But in this approach , I had to change a lot of things to keep to give the new item to initial state.
So, I want to avoid the replacing the edits done by user, so I was thinking something like below,
<script type="text/template" id="item_type1">
<div>
<div>Box</div>
</div>
</script>
<script type="text/template" id="item_type2">
<div>
<div>Box2</div>
</div>
</script>
And on add event, I want to do something like $('#item_type1').html() and $('#item_type2') to create new items.
I know there are sophisticated libraries like handlebar and mustache and underscore has its own way of implementing templates.
But I am not using any of these already and thus do not want to included them just to copy content. I dont want anything special. I am not passing variables. I am just cloning some markup to use again and again.
Is this way to insert html in script tags , going to work in all browsers ? and is it a good way ?
EDIT:
Its for the wp plugin and I assume js is turned on , else the plugin wont work anyways.
What about:
Your HTML should be, for example:
<script type="text/template" id="item_type1">
<div>
<h1>Box1</h1>
<p>
</p>
</div>
</script>
And your code would be:
var templateHtml = $('#item_type1').html();
var $item = $(templateHtml);
$('body').append($item);
$item.on('click', function() {});
This is an easy way that will work on all browsers.
Step 1: Create an HTML file with your template inside of it
Step 2: Using jQuery's load() method, call your HTML template into a div element in the main HTML file:
$("#main-div").load("yourtemplate.html")
Step 3: Be amazed
Is this a good idea? It depends:
If it's a self contained application on a known environment with a determined supported browser and with equally determined settings (like if JavaScript is on or not) then yea, sure. Why not?
If it's open to the public in every single browser possible with many different configurations, then no, it's a horrible idea. If your user doesn't have JavaScript enabled, then your content doesn't show up. Also, if one of your scripts break in production, then you are again left with no content. You can learn this lesson from when Gawker made this same mistake
I'm trying to set up pages as templates for an application that eventually needs to work offline.
Right now I'm playing around with snippets of HTML code (= enhanced but unformatted jquery mobile elements), which I'm storing as HTML pages like so:
<!-- template_listview.html -->
<!DOCTYPE html>
<html>
<head><title>static_listview_templates</title></head>
<body>
<!-- listview basic start -->
<ul id="tmp_listview_basic" class="ui-listview"></ul>
<!-- listview basic end -->
<!-- listview inset start -->
<ul id="tmp_listview_inset" class="ui-listview ui-listview-inset ui-corner-all ui-shadow"></ul>
<!-- listview inset end -->
</bdoy>
</html>
My application uses requireJS, so the first time the user hits a page that contains a listview (with a data-config attribute specifying dynamic content to load as well as listview appearance), require pulls the above template, which will be cached for all subsequent uses.
Right now the page above is returned as HTML string. As it will include all "variations" of listview elements (<ul>,<ol>,<li>...), I need some means of selecting the element I need on the specific occasion, which is where I'm stuck right now.
Question:
In terms of performance, is it better to work with a big string of the returned HTML template and try to extract the necessary substrings or should I instead wrap this into $() and use jquery/javascript to pull what I need?
If it should be a string, is there an easy way to pull an element (from to) from this string?
Thanks!
I'd assume string abstraction would be better performance-wise.
In fact, if I am right in thinking that you want to get the relevant listviews from the result as a string then according to the following jsperf test I wrote, string abstraction is much quicker:
http://jsperf.com/jqobj-vs-string-abstraction
Therefore, you can use the string abstraction method I wrote for that test to get your listviews from the result:
function getTemplateBlock(block, context) {
var regex = new RegExp('<!-- ' + block + '(.)+' + block + '(.)+?-->'),
tmpl = context.match(regex);
return tmpl.length ? tmpl[0].replace(/<!--[\s\S]*?-->/g, '') : '';
}
// get listview templates where 'mystuff' is
// the HTML string returned by your request
var basic = getTemplateBlock('listview basic', mystuff),
inset = getTemplateBlock('listview inset', mystuff);
Also, the answer to your question on how to select from your created object is in that jsperf too...
$('<div />').html(mystuff).find('ul');
This is necessary because .find() searches the descendants of the matched elements so if we make the matched element a new <div /> and append our result, we can search the <div /> for our <ul />'s.
Taken from the jQuery docs:
"Given a jQuery object that represents a set of DOM elements, the .find() method allows us to search through the descendants of these elements in the DOM tree and construct a new jQuery object from the matching elements."
Use $(html). It does pretty much exactly what you need. It's an in-memory operation. If you aren't planning to try to do hundreds of these a second, you'll get more bang for you buck focusing your performance optimization efforts on other areas as indicated by performance analysis tools like yslow or similar.
I'd like to know your thoughts about HTML code generation in my JS code.
I just think that the html.push("<tag>" + something + "</tag>") style pretty annoying.
I've already tried something with templates inside my HTML file (and put some placeholders therein), and then used its content to a replace the placeholders to my real values.
But maybe you guys have other ideas, possibly one using jQuery.
jQuery is the way to go. You can do things like this:
// create some HTML
var mySpan = $("<span/>").append("Something").addClass("highlight");
it is cross-browser compatible,
it is an easy to use syntax
There is also a templating plugin.
You can use createelement, appendchild, and innerHTML to do this.
Here's an article from A List Apart that uses these functions in the process of generating a dropdown menu.
jQuery has javascript template plugins like jBind and jTemplate. I haven't used them myself but I do recommend jQuery whenever possible.
A note on html generation, it is not searchable by search engines in most cases.
I'm a big fan of how PrototypeJS handles templates.
First you create an instance of the Template class and pass it a string containing the template HTML.
var tpl = new Template('Here is a link to #{sitename}');
Then you pass it data containing the values to replace within the template.
$('someDiv').innerHTML = tpl.evaluate( {link: 'http://www.stackoverflow.com', sitename: 'StackOverflow'} );
In the above example, I have a div with id="someDiv" and I'm replacing the contents of the div with the result of the template evaluation.
Resig has a little blog entry on creating a very lightweight template system.
There are a bunch of JQuery function that support this. In particular, you should look at append(content), appendTo(content) prepend(content) prependTo(content), replaceWith(content), after(content), before(content), insertAfter(content), and insertBefore(content).
I want JavaScript code to be separated from views.
I got the requirement to implement localization for a simple image button generated by JavaScript:
<img src="..." onclick="..." title="Close" />
What's the best technique to localize the title of it?
PS: I found a solution by Ayende. This is the right direction.
Edit:
I got Localization helper class which provides the Controller.Resource('foo') extension method.
I am thinking about to extend it (helper) so it could return all JavaScript resources (from "ClientSideResources" subfolder in App_LocalResources) for the specified controller by its name. Then - call it in BaseController, add it to ViewData and render it in Layout.
Would that be a good idea?
EDIT
Consider writing the necessary localized resources to a JavaScript object (hash) and then using it for lookup for your dynamically created objects. I think this is better than going back to the server for translations. This is similar to adding it via viewdata, but may be a little more flexible. FWIW, I could consider the localization resources to be part of the View, not part of the controller.
In the View:
<script type="text/javascript"
src='<%= Url.Content( "~/Resources/Load?translate=Close,Open" %>'></script>
which would output something like:
var local = {};
local.Close = "Close";
local.Open = "Open";
Without arguments it would output the entire translation hash. Using arguments gives you the ability to customize it per view.
You would then use it in your JavaScript files like:
$(function(){
$('#button').click( function() {
$("<img src=... title='" + local.Close + "' />")
.appendTo("#someDiv")
.click( function() { ... } );
});
});
Actually, I'm not too fussed about keeping my JavaScript code out of my views as long as the JavaScript code is localized in a container. Typically I'll set my master page up with 4 content area: title, header, main, and scripts. Title, header, and main go where you would expect and the scripts area goes at the bottom of the body.
I put all my JavaScript includes, including any for viewusercontrols, into the scripts container. View-specific JavaScript code comes after the includes. I refactor shared code back to scripts as needed. I've thought about using a controller method to collate script includes, that is, include multiple scripts using a single request, but haven't gotten around to that, yet.
This has the advantage of keeping the JavaScript code separate for readability, but also allows me to easily inject model or view data into the JavaScript code as needed.
Actually ASP.NET Ajax has a built-in localization mechanism: Understanding ASP.NET AJAX Localization
If you insist on keeping it separate, you could do something like:
//keep all of your localised vars somewhere
var title = '{title_from_server}';
document.getElementById('someImage').title = title;
Remember, if you use JavaScript code to initialize any text of elements, your site will degrade horribly where JavaScript isn't available.
I'm making a page which has some interaction provided by javascript. Just as an example: links which send an AJAX request to get the content of articles and then display that data in a div. Obviously in this example, I need each link to store an extra bit of information: the id of the article. The way I've been handling it in case was to put that information in the href link this:
<a class="article" href="#5">
I then use jQuery to find the a.article elements and attach the appropriate event handler. (don't get too hung up on the usability or semantics here, it's just an example)
Anyway, this method works, but it smells a bit, and isn't extensible at all (what happens if the click function has more than one parameter? what if some of those parameters are optional?)
The immediately obvious answer was to use attributes on the element. I mean, that's what they're for, right? (Kind of).
<a articleid="5" href="link/for/non-js-users.html">
In my recent question I asked if this method was valid, and it turns out that short of defining my own DTD (I don't), then no, it's not valid or reliable. A common response was to put the data into the class attribute (though that might have been because of my poorly-chosen example), but to me, this smells even more. Yes it's technically valid, but it's not a great solution.
Another method I'd used in the past was to actually generate some JS and insert it into the page in a <script> tag, creating a struct which would associate with the object.
var myData = {
link0 : {
articleId : 5,
target : '#showMessage'
// etc...
},
link1 : {
articleId : 13
}
};
<a href="..." id="link0">
But this can be a real pain in butt to maintain and is generally just very messy.
So, to get to the question, how do you store arbitrary pieces of information for HTML tags?
Which version of HTML are you using?
In HTML 5, it is totally valid to have custom attributes prefixed with data-, e.g.
<div data-internalid="1337"></div>
In XHTML, this is not really valid. If you are in XHTML 1.1 mode, the browser will probably complain about it, but in 1.0 mode, most browsers will just silently ignore it.
If I were you, I would follow the script based approach. You could make it automatically generated on server side so that it's not a pain in the back to maintain.
If you are using jQuery already then you should leverage the "data" method which is the recommended method for storing arbitrary data on a dom element with jQuery.
To store something:
$('#myElId').data('nameYourData', { foo: 'bar' });
To retrieve data:
var myData = $('#myElId').data('nameYourData');
That is all that there is to it but take a look at the jQuery documentation for more info/examples.
Just another way, I personally wouldn't use this but it works (assure your JSON is valid because eval() is dangerous).
<a class="article" href="link/for/non-js-users.html">
<span style="display: none;">{"id": 1, "title":"Something"}</span>
Text of Link
</a>
// javascript
var article = document.getElementsByClassName("article")[0];
var data = eval(article.childNodes[0].innerHTML);
Arbitrary attributes are not valid, but are perfectly reliable in modern browsers. If you are setting the properties via javascript, than you don't have to worry about validation as well.
An alternative is to set attributes in javascript. jQuery has a nice utility method just for that purpose, or you can roll your own.
A hack that's going to work with pretty much every possible browser is to use open classes like this: <a class='data\_articleid\_5' href="link/for/non-js-users.html>;
This is not all that elegant to the purists, but it's universally supported, standard-compliant, and very easy to manipulate. It really seems like the best possible method. If you serialize, modify, copy your tags, or do pretty much anything else, data will stay attached, copied etc.
The only problem is that you cannot store non-serializable objects that way, and there might be limits if you put something really huge there.
A second way is to use fake attributes like: <a articleid='5' href="link/for/non-js-users.html">
This is more elegant, but breaks standard, and I'm not 100% sure about support. Many browsers support it fully, I think IE6 supports JS access for it but not CSS selectors (which doesn't really matter here), maybe some browsers will be completely confused, you need to check it.
Doing funny things like serializing and deserializing would be even more dangerous.
Using ids to pure JS hash mostly works, except when you try to copy your tags. If you have tag <a href="..." id="link0">, copy it via standard JS methods, and then try to modify data attached to just one copy, the other copy will be modified.
It's not a problem if you don't copy tags, or use read only data. If you copy tags and they're modified you'll need to handle that manually.
Using jquery,
to store: $('#element_id').data('extra_tag', 'extra_info');
to retrieve: $('#element_id').data('extra_tag');
I know that you're currently using jQuery, but what if you defined the onclick handler inline. Then you could do:
<a href='/link/for/non-js-users.htm' onclick='loadContent(5);return false;'>
Article 5</a>
You could use hidden input tags. I get no validation errors at w3.org with this:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html lang='en' xml:lang='en' xmlns='http://www.w3.org/1999/xhtml'>
<head>
<meta content="text/html;charset=UTF-8" http-equiv="content-type" />
<title>Hello</title>
</head>
<body>
<div>
<a class="article" href="link/for/non-js-users.html">
<input style="display: none" name="articleid" type="hidden" value="5" />
</a>
</div>
</body>
</html>
With jQuery you'd get the article ID with something like (not tested):
$('.article input[name=articleid]').val();
But I'd recommend HTML5 if that is an option.
Why not make use of the meaningful data already there, instead of adding arbitrary data?
i.e. use <a href="/articles/5/page-title" class="article-link">, and then you can programmatically get all article links on the page (via the classname) and the article ID (matching the regex /articles\/(\d+)/ against this.href).
As a jQuery user I would use the Metadata plugin. The HTML looks clean, it validates, and you can embed anything that can be described using JSON notation.
This is good advice. Thanks to #Prestaul
If you are using jQuery already then you should leverage the "data"
method which is the recommended method for storing arbitrary data on a
dom element with jQuery.
Very true, but what if you want to store arbitrary data in plain-old HTML? Here's yet another alternative...
<input type="hidden" name="whatever" value="foobar"/>
Put your data in the name and value attributes of a hidden input element. This might be useful if the server is generating HTML (i.e. a PHP script or whatever), and your JavaScript code is going to use this information later.
Admittedly, not the cleanest, but it's an alternative. It's compatible with all
browsers and is valid XHTML. You should NOT use custom attributes, nor should you really use attributes with the 'data-' prefix, as it might not work on all browsers. And, in addition, your document will not pass W3C validation.
As long as you're actual work is done serverside, why would you need custom information in the html tags in the output anyway? all you need to know back on the server is an index into whatever kind of list of structures with your custom info. I think you're looking to store the information in the wrong place.
I will recognize, however unfortunate, that in lots of cases the right solution isn't the right solution. In which case I would strongly suggest generating some javascript to hold the extra information.
Many years later:
This question was posted roughly three years before data-... attributes became a valid option with the advent of html 5 so the truth has shifted and the original answer I gave is no longer relevant. Now I'd suggest to use data attributes instead.
<a data-articleId="5" href="link/for/non-js-users.html">
<script>
let anchors = document.getElementsByTagName('a');
for (let anchor of anchors) {
let articleId = anchor.dataset.articleId;
}
</script>
I advocate use of the "rel" attribute. The XHTML validates, the attribute itself is rarely used, and the data is efficiently retrieved.
So there should be four choices to do so:
Put the data in the id attribute.
Put the data in the arbitrary attribute
Put the data in class attribute
Put your data in another tag
http://www.shanison.com/?p=321
You could use the data- prefix of your own made attribute of a random element (<span data-randomname="Data goes here..."></span>), but this is only valid in HTML5. Thus browsers may complain about validity.
You could also use a <span style="display: none;">Data goes here...</span> tag. But this way you can not use the attribute functions, and if css and js is turned off, this is not really a neat solution either.
But what I personally prefer is the following:
<input type="hidden" title="Your key..." value="Your value..." />
The input will in all cases be hidden, the attributes are completely valid, and it will not get sent if it is within a <form> tag, since it has not got any name, right?
Above all, the attributes are really easy to remember and the code looks nice and easy to understand. You could even put an ID-attribute in it, so you can easily access it with JavaScript as well, and access the key-value pair with input.title; input.value.
One possibility might be:
Create a new div to hold all the extended/arbitrary data
Do something to ensure that this div is invisible (e.g. CSS plus a class attribute of the div)
Put the extended/arbitrary data within [X]HTML tags (e.g. as text within cells of a table, or anything else you might like) within this invisible div
Another approach can be to store a key:value pair as a simple class using the following syntax :
<div id="my_div" class="foo:'bar'">...</div>
This is valid and can easily be retrieved with jQuery selectors or a custom made function.
In html, we can store custom attributes with the prefix 'data-' before the attribute name like
<p data-animal='dog'>This animal is a dog.</p>.
Check documentation
We can use this property to dynamically set and get attributes using jQuery like:
If we have a p tag like
<p id='animal'>This animal is a dog.</p>
Then to create an attribute called 'breed' for the above tag, we can write:
$('#animal').attr('data-breed', 'pug');
To retrieve the data anytime, we can write:
var breedtype = $('#animal').data('breed');
At my previous employer, we used custom HTML tags all the time to hold info about the form elements. The catch: We knew that the user was forced to use IE.
It didn't work well for FireFox at the time. I don't know if FireFox has changed this or not, but be aware that adding your own attributes to HTML elements may or may-not be supported by your reader's browser.
If you can control which browser your reader is using (i.e. an internal web applet for a corporation), then by all means, try it. What can it hurt, right?
This is how I do you ajax pages... its a pretty easy method...
function ajax_urls() {
var objApps= ['ads','user'];
$("a.ajx").each(function(){
var url = $(this).attr('href');
for ( var i=0;i< objApps.length;i++ ) {
if (url.indexOf("/"+objApps[i]+"/")>-1) {
$(this).attr("href",url.replace("/"+objApps[i]+"/","/"+objApps[i]+"/#p="));
}
}
});
}
How this works is it basically looks at all URLs that have the class 'ajx' and it replaces a keyword and adds the # sign... so if js is turned off then the urls would act as they normally do... all "apps" (each section of the site) has its own keyword... so all i need to do is add to the js array above to add more pages...
So for example my current settings are set to:
var objApps= ['ads','user'];
So if i have a url such as:
www.domain.com/ads/3923/bla/dada/bla
the js script would replace the /ads/ part so my URL would end up being
www.domain.com/ads/#p=3923/bla/dada/bla
Then I use jquery bbq plugin to load the page accordingly...
http://benalman.com/projects/jquery-bbq-plugin/
I have found the metadata plugin to be an excellent solution to the problem of storing arbitrary data with the html tag in a way that makes it easy to retrieve and use with jQuery.
Important: The actual file you include is is only 5 kb and not 37 kb (which is the size of the complete download package)
Here is an example of it being used to store values I use when generating a google analytics tracking event (note: data.label and data.value happen to be optional params)
$(function () {
$.each($(".ga-event"), function (index, value) {
$(value).click(function () {
var data = $(value).metadata();
if (data.label && data.value) {
_gaq.push(['_trackEvent', data.category, data.action, data.label, data.value]);
} else if (data.label) {
_gaq.push(['_trackEvent', data.category, data.action, data.label]);
} else {
_gaq.push(['_trackEvent', data.category, data.action]);
}
});
});
});
<input class="ga-event {category:'button', action:'click', label:'test', value:99}" type="button" value="Test"/>
My answer might not apply to your case. I needed to store a 2D table in HTML, and i needed to do with fewest possible keystrokes. Here's my data in HTML:
<span hidden id="my-data">
IMG,,LINK,,CAPTION
mypic.jpg,,khangssite.com,,Khang Le
funnypic.jpg,,samssite.com,,Smith, Sam
sadpic.png,,joyssite.com,,Joy Jones
sue.jpg,,suessite.com,,Sue Sneed
dog.jpg,,dogssite.com,,Brown Dog
cat.jpg,,catssite.com,,Black Cat
</span>
Explanation
It's hidden using hidden attribute. No CSS needed.
This is processed by Javascript. I use two split statements, first on newline, then on double-comma delimiter. That puts the whole thing into a 2D array.
I wanted to minimize typing. I didn't want to redundantly retype the fieldnames on every row (json/jso style), so i just put the fieldnames on the first row. That a visual key for the programmer, and also used by Javascript to know the fieldnames. I eliminated all braces, brackets, equals, parens, etc. End-of-line is record delimiter.
I use double-commas as delimiters. I figured no one would normally use double-commas for anything, and they're easy to type. Beware, programmer must enter a space for any empty cells, to prevent unintended double-commas. The programmer can easily use a different delimiter if they prefer, as long as they update the Javascript. You can use single-commas if you're sure there will be no embedded commas within a cell.
It's a span to ensure it takes up no room on the page.
Here's the Javascript:
// pull 2D text-data into array
let sRawData = document.querySelector("#my-data").innerHTML.trim();
// get headers from first row of data and load to array. Trim and split.
const headersEnd = sRawData.indexOf("\n");
const headers = sRawData.slice(0, headersEnd).trim().split(",,");
// load remaining rows to array. Trim and split.
const aRows = sRawData.slice(headersEnd).trim().split("\n");
// trim and split columns
const data = aRows.map((element) => {
return element.trim().split(",,");
});
Explanation:
JS uses lots of trims to get rid of any extra whitespace.