I would like to add new properties to DynatreeNode class. For example in methods OnSelect I want to use node.myproperty. node.myproperty value is calculated from some DOM element. Is there a way to do this? I tried using jQuery extend, but it does'nt seem to be possible.
this is JavaScript, so you can create a new attribute virtually everywhere, simply by assigning it ;-)
For Dynatree, the recommended place would be the node.data object, e.g.
node.data.foo = "bar";
then access it:
onSelect(node){
if(node.data.foo !== undefined){
alert(node.data.foo);
}
}
Related
I have this code in javascript
var greet;
greet = function() {
var textoNombre;
textoNombre = document.getElementById("textoNombre");
return alert(textoNombre.value);
};
what is working on the HTML document. But if I change document.getElementById("textoNombre") by the jQuery version $("#textoNombre") it just dont work. The alert says "undefined".
I have the jQuery script linked on the head of the HTML before to my custom js file.
This is a very basic question but I tried different things and no one work, can you help me please? Thank you in advance.
That's because jQuery objects don't have a value property, the equivelant is $('#someId').val().
To get the underlying DOM object, you can use $('#someId')[0]. This is because jQuery objects are actually like arrays, and their elements are the DOM objects themselves. That means $('#someId')[0].value would work as you'd expect.
jQuery objects are not DOM objects and don't share all their properties.
To get the current value of a form control, you would use the .val() method, not the .value property.
When you want to get the HTML of an entire DOM element (wrapper included), you can do the following (as explained here):
$('#myElementId')[0].outerHTML
But what you can't do is call outerHTML on $(this) inside e.g. a click listener or selector function body scope:
$(this).outerHTML //Doesn't complete in IntelliSense, returns undefined in browser
or
$(this)[0].outerHTML //Correction, this DOES work, but it doesn't complete in IntelliSense
because IntelliSense won't show innerHTML or outerHTML in those circumstances, although with vanilla JavaScript you can do:
document.getElementById($(this).attr('id')).outerHTML
So... what's up with that?
outerHTML is a DOM property; jQuery doesn't expose all DOM properties.
If you have a jQuery object, you can only directly access those properties and methods that jQuery exposes, and vice versa for DOM objects.
In object-oriented terms, jQuery objects don't inherit from DOM objects, they contain them.
Saying $x[0] gets you the DOM object for the first element represented by a jQuery object.
You can use directly this to access outerHTML of the current object instead of indirectly going through $(this) as this represents the DOM object (which has outerHTML property) whereas $(this) represents jQuery object.
this.outerHTML
jQuery selector returns an array-like jQuery object which has no outerHTML property.
However, the jQuery resulting array contains DOM elements.
It means that you can actually access it this way.
$(".someClass")[0].outerHTML // it works for me
Update:
It works for me in every browser.
I can access array-like jQuery object in a click event handler as well.
$(".someClass").click(function()
{
alert($(this)[0].outerHTML); // it works me too
});
Here is my JSFiddle: http://jsfiddle.net/13btf60p/
Update 2:
OK, now I get your question. It should have worked.
Do you really need an IntelliSense to complete such a plain and simple construction?
I will add what I found to be the correct solution to what ended up being a simple flaw in the default Visual Studio settings for future reference.
Since I didn't want to let this go, I searched further and found out that, by default, jQuery IntelliSense is somewhat deplorable out of the box in Visual Studio 2013.
Under
Tools > Options > Text Editor > Javascript > IntelliSense > References
I set
Reference Group: "Implicit (Web)"
and added an existing jQuery file. This solved all issues of my question and IntelliSense now suggests all members and methods correctly, although this should have simply worked out of the box instead of costing everyone a bunch of time.
this.outerHTML is enough.
If you use getElementById maybe you can use:
var table = document.getElementById('blablabla');
I am wondering if I could use query and javascript together so I could select an element by class with the javascript and then use javascript to work on that element. Sorry if that didn't make sense. Here is an example:
$('.nav_flag').src = "images/flags/"+userCountryLower+".gif";
Would that work, if not how do I get an element by class using regular javascript. Thanks!
EDIT:I know JQUERY is JavaScript but I was wondering if I could mix jquery selectors and javascript 'controller'-for a loss of a better word
To answer your question as asked, there are several ways to take a jQuery object, i.e., what is returned by $('some selector'), and get a reference to the underlying DOM element(s).
You can access the individual DOM elements like array elements:
// update the src of the first matching element:
$(".nav_flag")[0].src = "images/flags/"+userCountryLower+".gif";
// if you're going to access more than one you should cache the jQuery object in
// a variable, not keep selecting the same thing via the $() function:
var navFlgEls = $(".nav_flag");
for (var i = 0; i < navFlgEls.length; i++) { ... }
But you wouldn't manually loop through the elements when you can use jQuery's .each() method, noting that within the callback function you provide this will be set to the current DOM element:
$(".nav_flag").each(function() {
this.src = "images/flags/"+userCountryLower+".gif";
});
However, jQuery provides a way to set attributes with one line of code:
$(".nav_flag").attr("src", "images/flags/"+userCountryLower+".gif");
To answer the second part of your question, doing the same thing without jQuery, you can use .getElementsByClassname() or .querySelectorAll() if you don't care about supporting older browsers.
jQuery IS Javascript. You can mix and match them together. But you better know what you're doing.
In this case, you probably want to use .attr function to set value of attribute.
Use .attr() in jQuery, rather than mix the two here.
$('.nav_flag').attr('src', "images/flags/"+userCountryLower+".gif");
In many instances, it is fine to mix jQuery with plain JavaScript, but if you have already included the jQuery library, you might as well make use of it. Unless, that is, you have an operation which in jQuery would be more computationally expensive than the same operation in plain JavaScript.
You can do it with jQuery too:
$('.nav_flag').attr("src", "images/flags/"+userCountryLower+".gif");
keep in mind that jQuery is simply a library built upon javascript.
for any jQuery object, selecting its elements by subscription will return the corresponding dom element.
e.g.
$('#foo')[0] // is equivalent to document.getElementById('foo');
You need to add an index to the jQuery object to get the native Javascript object. Change:
$('.nav_flag').src = "images/flags/"+userCountryLower+".gif";
To:
$('.nav_flag')[0].src = "images/flags/"+userCountryLower+".gif";
To get elements by class name in Javascript you can use:
document.getElementsByClassName( 'nav_flag' )[0].src = "images/flags/"+userCountryLower+".gif";
To answer your question, you could use .toArray() to convert the jQuery object into an array of standard DOM elements. Then either get the first element or loop through the array to set all the elements with the class.
However, you could do this easier with pure jquery with attr or prop depending on the version:
$('.nav_flag').attr("src", "images/flags/"+userCountryLower+".gif");
Or use pure javascript:
if (navFlagElements = document.getElementsByClassName("nav_flag") && navFlagElements.length > 0) {
navFlagElements[0].src = "images/flags/"+userCountryLower+".gif"
}
document.getElementById("main").src = '02.jpg';
works
but
$('#main').src = '02.jpg';
doesn't
$("#main").attr("src", "02.jpg");
$('#main') returns a jQuery object, not a HTMLElement, therefore no src property is defined on the jQuery object. You may find this article useful.
Mike has shown one way of setting the src attribute (the way he has shown could probably be considered the most jQuery like way of doing it). A couple of other ways
$("#main")[0].src = '02.jpg';
or
$("#main").get(0).src = '02.jpg';
$('#main').src = '02.jpg';
The jQuery wrapper you get from $(...) does not reproduce all properties and methods of the DOM object(s) it wraps. You have to stick to jQuery-specific methods on the wrapper object: in this case attr as detailed by Mike.
The ‘prototype’ library, in contrast to jQuery, augments existing DOM objects rather than wrapping them. So you get the old methods and properties like .src in addition to the new ones. There are advantages and drawbacks to both approaches.
$("#main") is a collection of matches from a search. document.getElementById("main") is a single DOM element - that does have the src property. Use the attr(x,y) method for when you want to set some attribute on all of the elements in the collection that gets returned by $(x), even if that is only a single element as in getElementById(x).
It's akin to the difference between int and int[] - very different beasts!
I'm trying to find a way that will add / update attribute using JavaScript. I know I can do it with setAttribute() function but that doesn't work in IE.
You can read here about the behaviour of attributes in many different browsers, including IE.
element.setAttribute() should do the trick, even in IE. Did you try it? If it doesn't work, then maybe
element.attributeName = 'value' might work.
What seems easy is actually tricky if you want to be completely compatible.
var e = document.createElement('div');
Let's say you have an id of 'div1' to add.
e['id'] = 'div1';
e.id = 'div1';
e.attributes['id'] = 'div1';
e.createAttribute('id','div1')
These will all work except the last in IE 5.5 (which is ancient history at this point but still is XP's default with no updates).
But there are contingencies, of course.
Will not work in IE prior to 8:e.attributes['style']
Will not error but won't actually set the class, it must be className:e['class'] .
However, if you're using attributes then this WILL work:e.attributes['class']
In summary, think of attributes as literal and object-oriented.
In literal, you just want it to spit out x='y' and not think about it. This is what attributes, setAttribute, createAttribute is for (except for IE's style exception). But because these are really objects things can get confused.
Since you are going to the trouble of properly creating a DOM element instead of jQuery innerHTML slop, I would treat it like one and stick with the e.className = 'fooClass' and e.id = 'fooID'. This is a design preference, but in this instance trying to treat is as anything other than an object works against you.
It will never backfire on you like the other methods might, just be aware of class being className and style being an object so it's style.width not style="width:50px". Also remember tagName but this is already set by createElement so you shouldn't need to worry about it.
This was longer than I wanted, but CSS manipulation in JS is tricky business.
Obligatory jQuery solution. Finds and sets the title attribute to foo. Note this selects a single element since I'm doing it by id, but you could easily set the same attribute on a collection by changing the selector.
$('#element').attr( 'title', 'foo' );
What do you want to do with the attribute? Is it an html attribute or something of your own?
Most of the time you can simply address it as a property: want to set a title on an element? element.title = "foo" will do it.
For your own custom JS attributes the DOM is naturally extensible (aka expando=true), the simple upshot of which is that you can do element.myCustomFlag = foo and subsequently read it without issue.