In the following example PositionedRectangle is a subclass of Rectangle, all 3 methods of prototype inheritance seem to produce the same results, method 1 is from the authors book (Flanagan's Definitive Guide 5ed) example 9-3, and method 2 is from his website example 9-3, and method 3 is my own;
// method 1 seems most complicated
function heir(p) {
function f(){};
[code]....
I am newer in Jquery. How to create the prototype object and custom object in Jquery.
View 2 Replies View RelatedWhat I have been doing so far to make a "class"/Reusable object is this:
PHP Code:
function Dog(){
this.name name;
this.bark = function(){
[code]...
However, recently I have been reading a book on Javascript and it said that the problem with this way of doing it, is that the bark() function will be loaded into memory for each Dog object created this way, while the body of that function is the same for each object.
- A Person class with a name property and a jump() method.
- An animal class with a isMammal property and move() method.
- A Dog class with a numberOfLegs property and a bark() method which is a subclass of Animal (thus inherits the isMammal property and move() method.
- Each of those classes in its own file.
This book I've been reading is actually pretty good, but at some points it's explanation is not rich enough.It explains that functions are objects and that objects in javascript are just key-value pairs. It says that each function has a prototype property which points to a blank Object(), but you can make it point to something else? or maybe I misunderstood it. I still don't understand how it really works.
I have a table (tables are for tabular data) with patient information. The user can click the row to select it and when they do the right part of the interface loads some additional information on the patient - quick lookup info if you will, but also provides links to tasks involving that information - edit, view case history, etc.I'd like to replace the default right click behavior on the rows to create a pop up menu next to the point of click that links to the same list of options for the convenience of the more savvy users.The project is being built with prototype so no jQuery please. The site is a corporate intranet where Firefox is the only browser it is *required* to work in. It would be nice to have it work in webkit.
View 4 Replies View RelatedHow can I subclass a native class to get my own class with all the
function of the native clas, plus correct instanceof behaviour?
The scenario I'm thinking of is something like
function MyArray() {
Array.apply( this, arguments );
}
MyArray.prototype = new Array();
MyArray.prototype.constructor = MyArray;
var marr = new MyArray();
marr[0] = "abc";
marr.length == 1; // true
marr instanceof MyArray; // true
But this seems impossible due to the Array constructor returning a new
object even when called with my own "this" in the apply() above. Can
this be solved in any way?
What I'm trying to do is when the mouse hover on the level1 class, I want level2 class change it's background color. But I do not know how to reference a subclass.
<div class="level1">
<span class="level2">One</span>
</div>
[code]....
I have a superclass where I create a "div" element as a property and then proceed to try and set the element's "id" attribute in a subclass. Interestingly, if I create multiple instances of the subclass with different "id"s, they all end up having the last "id" I specify. I would like it if they retain the individual "id" I specify. Here is the code.
function Drag() {
this.ele = document.createElement("div"); }
function Icon(id) {
this.ele.id = id; }
Icon.prototype = new Drag();
var hello = new Icon("hello");
var goodbye = new Icon("goodbye");
To have all the :hover subclass fade from their passive states, instead of changing instantaneously? i just can t figure if such an effect can be done.
View 1 Replies View RelatedAccording to ECMAScript, the root of the prototype chain is Object.Prototype. Each object has an internal property [[Prototype]] that could be another object or NULL.... However, it also says that every function has the Function prototype object: Function.Prototype, it confused me, because a function is an object, for a function object, what is its function prototype and object prototype..For example:
var x = function (n) {return n+1;};
what is the relationships of x, Object.Prototype and Function.Prototype
I am trying to get to the bottom of javascript object, prototypes etc. I have a fairly good grasp of it, but I get confused the closer I get to the base object.prototype. FIrst of all, I was under the impression that all objects descend directly from Object. But some objects (like Array) seem to inherit properties and methods from the function.prototype. So does this mean that the chain is like this:
object -- function -- array Second, I noticed (on the mozilla javascript reference site that object.prototype inherits properties and methods from function.prototype and vice versa!? How can this be? I must be missing something important about understanding the chain?
I have files on the server: .txt, .xml, .config, and "no extension" - all editable with notepad.
User will write some input, it will be added to file in specific place.
I need an ability to change element value in file (in one of them - depends what user choose) (or it even can be some trigger word it-self like CHANGE_ME for not to use attributes)
Create a temporary copy of edited file and create a unique temporary link to it.
I don't know what to start from.... For now I know how to make XHR, but what to do with other extensions?
Have no idea how to save the NEW file (a copy of original file) on server , and create a UNIQUE link ,and delete the file right after it was downloaded.
I can find a specific word in xml file, but how to change it?[code]...
I can use "with" like this:
function MyObject(message)
{
this.message = message;
}
function _MyObject_speak()
{
alert(this.message);
}
with (MyObject)
{
prototype.speak = _MyObject_speak;
}
I was wondering why I can't use "with" like this:
with (MyObject.prototype)
{
speak = _MyObject_speak;
}
One of the complaints about prototype.js (google for it if you're not
familiar with it) is that it's poorly documented. I have this inkling
that the key to understanding prototype.js is in the bind function.
The problem with Javascript is that the "this" operator is poorly
overloaded and it is often hard to understand in the context of
object-oriented javascript
So, let's start with the definition:
Function.prototype.bind = function(object) {
var method = this;
return function() {
method.apply(object, arguments);
}
}
As I read this, it states that all functions (which are themselves
objects) will, in the future, have an associated method called "bind".
The function() function, so to speak, simply instantiates a Function
object with the parameter list and then evals the statement, sticking
the resulting execution-tree in the current code frame.
The "this" there refers to the function object associated with the call
to bind(), right? But the word "arguments" there refers to the
arguments passed to the function object *generated by* the call to
bind().
In every example within prototype.js, bind() is called either in a
constructor or within a method contexted to a javascript object, and is
always called with "this" as its argument, e.g.:
this.options.onComplete = this.updateContent.bind(this);
As I read the code it seems to be stating that the "this" object
referred to within bind()'d functions are being coerced into always
referring to the current instantiated object.
But isn't this always the case anyway? Is this a rather confusing
attempt to ensure "this" purity whereby the call
method.apply(object, arguments)
is forced to always have the reference to the containing object present?
I think I've got it. Bind() generates uniq functions that contain live
references to the objects to which they belong, such that the function
object can then be passed to setTimeout() or onMouseOver(), handlers
that accept functions but not objects.
Lets say we run: window.alert = function() { };
Is there anyway to 'restore' the original alert() method or is it gone
forever?
I know you can do window.alert = Window.prototype.alert, but lets say
you also set Window.prototype.alert = function() { } or lets say we're
in Opera, which doesnt have a Window "class".
I would like to set up an event observer outside of an object, so I
can't use this.bindAsEventListener. How can I pass the correct object
reference?
I tried something like this, and various other variations, but no luck.
This works when I set it up from inside the object, using "this.",
Event.observe(targetId,'click',targetId.select.bin dAsEventListener(this),false);
I wanted to add an object as a prototype to separate my methods more
nicely, however, I ran into a couple of problems. Apart from the
obvious "scope" issues I found that any instances of my class shared
the objects methods and properties.
I realise (now) that this is actually how prototypes work, they share
functions and objects rather than create new instances of them for
every "class", but is there any way around it? (or shouldn't I be doing
things like this at all?) Code:
I am working on my own pop up calendar, mainly because the one I am currently using crashes the Safari browser at times.
So, I want to verify that what I am doing will work, in that I want to be able to have multiple calendars open at the same time, each independent of the other.
So, I start it off with:
var Calendar = {
dateSelected: null,
topPos:null,
leftPos:null,
somefunction:function(e) {
...
}
};
If I create more than one calendar object, will they have their own variables, in that the dateSelected, topPos and leftPos will be unique to that instance?
Or, is there a better way to do this, that is cross-platform.....
In my research in the javascript language I have encountered problems
with implementing prototype inheritance while preserving private
methods functioning properly. Here is an example: Code:
I want ask you if, for a web portal/application, is better prototype or Jquery? I don't want to innesc some type of flame, but after the announce that drupal use JQuery and that the new Wordpress
2.2 use Jquery I ask myself if my choice of use prototype.js is the bettere choice.
I have <div id ="changeable"> with some html in it. I have a link that calls the function to replace the info in the div. The problem is that the "creative_development.inc" file is added to the top of the div and does not replace the content. How do I replace the content, and not just add content?
View 1 Replies View RelatedI'm trying to make an addEvent function that will automatically attach itself to the object using a class.
My question is how can I add the function so when I write obj.addEvent("click",myfunction); it will add the event?
Here's my current function:
this.prototype.addEvent = function(type,fn)
{
if(window.attachEvent)
this.attachEvent("on"+type,fn);
else if(window.addEventListener)
this.addEventListener(type,fn,false);
}
I need help to workaround the following problem:
First, about the environment:
- The web pages automatically generated.
- Pages can be inserted to each other
- When a subpage to be inserted is being generated, it does not know will it be inserted or not.
- That because each subpage uses the <script src=...> tags to load the script it needs.
- in the external script files I'm trying to protect it from repeated execution checking (if(){}) the value of a variable which is created after in the script.
Everything worked fine until I tried to use the .prototype to declare the method of my objects.
In the Internet Explorer, I got "Object does not support this property or method", on the access to a prototype function, because the prototype of my object was deleted by itself after the second load of the external script. Code:
This function will return an array of the elements in a page that contain a certain attribute, you can also give it a value that the attribute has to match, a tag name that the element has to match and a parent element.
I know there are other functions for doing this, but this one is written for use with the prototype (http://prototype.conio.net/) JavaScript library, in fact its really just a modified version of the getElementsByClassName() function that’s part of prototype.
document.getElementsByAttribute = function(attribute, value, tagName, parentElement) {
var children = ($(parentElement) || document.body).getElementsByTagName((tagName || '*'));
return $A(children).inject([], function(elements, child) {
var attributeValue = child.getAttribute(attribute);
if(attributeValue != null) {
if(!value || attributeValue == value) {
elements.push(child);
}
}
return elements;
});
}
Usage is pretty simple, this will return all elements with a width attribute:
I try to get a xml-response with prototype. for e.g. i have the following code:
<html>
<head>
<title>Test Ajax</title>
<script src="prototype-1.3.1.js" type="text/javascript"></script>
<script type="text/javascript">
//<![CDATA[
var getXML = function()
{
var myAjax = new Ajax.Request(
"bsp.xml",
{
method:'GET',
onComplete:showXML
}
);
}
var showXML = function(r)
{
var names = [];
var root = r.responseXML.getElementsByTagName('personal').item(0);
// root
for (var i = 0; i < root.childNodes.length; i++)
{
var node = root.childNodes.item(i); // mitarbeiter
names.push(node.childNodes.item(1).firstChild.data);
}
$('xml').innerHTML = names.join("<br />");
}
//]]>
</script>
</head>
<body>
<p>
<a href="#" onclick="getXML();return false;">TEST</a>
</p>
<div id="xml">
</div>
</body>
</html>
xml-Data:
<?xml version="1.0" ?>
<personal>
<mitarbeiter>
<vorname>John</vorname>
<name>Brown</name>
</mitarbeiter>
<mitarbeiter>
<vorname>Matt</vorname>
<name>Blue</name>
</mitarbeiter>
</personal>
This works fine in IE but in Geko-Browser i got nothing back, because this browsers build the DOM with linebreaks and whitespace. Do you have any ideas what is wrong in my code and how to get propper DOM?
Having read through Sergio Pereira's Prototype documentation I came across the grep command within Enumerable object.
This is something that looks very interesting. Such as being able to quickly select only the elements you want using a regular expression.
But for the life in me I can seem to get it to work.
Anyone a bit more up to speed with Prototype care to have a look?
var elementList = Form.getElements("just-a-form");
nodes = $A(elementList);
var localElements = nodes.grep( /image/, function(node){
return node.id
});
I'm using Prototype's AJAX to get the "alert" the response of a simple PHP script (a script that echoes a single line), but it doesn't seem to work. Here's the code:
function init()
{
var url = "http://localhost/script.php";
var myAjax = new Ajax.Request(
url,
{
onSuccess: showResponse
});
}
function showResponse(response)
{
alert(response.responseText);
}
window.onload = init;
The code has no errors, but still doesn't show the response even if i add an onFailure event handler. What could be wrong?