've made classes, in prototype, for various projects and have now come to a point where I am a bit stuck. In the past I had trouble with scoping issues and having to bind the current object to the this keyword, so I can use it in 'lexical closures'(not sure if that's the correct terminology).Example:
var Example = Class.create({
initialize : function() {
this.newElement = $(something);
[code]....
What 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.
What organization standardizes Javascript? Like, w3c standardizes a lot of stuff, the things they list at w3.org, so what organization standardizes Javascript? Is it still Netscape (a part of AOL now, but I guess Netscape would still be doing it.)
View 2 Replies View Relatedwhich is the organization that decides JavaScript standards?
View 1 Replies View RelatedIs there any organization chart(Hierarchy) available in jquery. like google org char? It should work in intranet.
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 know that it is possible to create map via javascript, which has some spots used like links.
I have 3 images:
background, house and man.
Also 3 php variables:
$man = 'yes';
$background = 'yes';
$house = 'no';
What I need is to make javascript map which would show background(yes) and man (yes). House must be invisible, because I have NO.
The problem, that man must appear to 21px width 100px height and be active as a link.
If you haven't understood what I want - ask.
Now I will try to explain this with example.
You have a map with countries. But map is like image and you can't do anything. If variable with country gets value "yes" - the country become active on the map and you can push on it.
How do you create dynamic element such as ifram, div, table , etc.... With the X library
View 1 Replies View RelatedMy code: [URL]... When I click on Upraviť in class edit I need add some HTML code to begin and to end of class entry how to I can select class entry in the same class post on which I clicked?
View 1 Replies View RelatedI'm building a DIV dynamically and putting a P into it like so:
var oDiv = document.createElement("DIV");
var oP = document.createElement("P");
oP.style.backgroundColor = "green";
oP.appendChild( document.createTextNode("some sample text") );
oDiv.appendChild(oP);
oDiv.style.position = "absolute";
oDiv.style.left = "100px";
oDiv.style.top = "100px";
oDiv.style.width = "200px";
oDiv.style.height = "150px";
oDiv.style.backgroundColor = "blue";
document.body.appendChild(oDiv);
The problem is that FF doesn't put the P in the top left corner of the
DIV. Rather it seem to push it down by a line height. Is there some
white space sneaking into the DIV? How do I get the P right into the top
left corner?
can anybody tell me how you can create a new stylesheet inside a
(X)HTML page with JavaScript and Firefox, if the stylesheet is only
available as a variable value, like:
var CSSStyle = "rect {fill: lightgrey;}
circle {fill: red;}
polyline {fill: none; stroke: red; stroke-width: 0.3;}
text {font-size: 2.5px;}
text.text-x-axis {text-anchor: middle;}
text.text-y-axis {text-anchor: end;}"
So far, the only workaround I found, was to link an empty stylesheet to
the page
<link rel="stylesheet" type="text/css" href="./empty.css"/>
and then use the insertRule method on this stylesheet for every single
rule from the variable (indexOf('}') / substring()).
I'm working on a script for Hulu that will present the user with some options, then automatically sort their queue depending on those options (a blessing for someone like me with 450+ entries). The sequence is as such:Read and store all entry rowsPresent user with a form to assign shows to categoriesPresent user with a form to assign weights to categories (so something can show up more or less often in a "block") as well as options for how to sort entriesSort previous row listings based on user inputDecide the order of shows and change the values of their respective "Order" boxesI've gotten it to work up until this last part. I'm creating the dialogue boxes using proper DOM input (at least, I believe so), but for some reason I can't use getElementById() or getElementsByName(). I can use getElementsByClassName() and getElementsByTagName(). When trying to use the first two, I'm just told that it isn't a function.
Here's the code section itself, the problem line is Line 3:
Javascript Code:
This is inside an onclick event; finalBox is declared outside of that handler. I'm able to use finalBox.getElementsByClassName in the same function about 20 lines up. For reference, here's where I create the elements I'm trying to find:
Javascript Code:
CustRow is a function that helps me shorten the code of adding a cell to a row (with addCell()); it creates a row element and attaches it to the given table element.
That first piece of code is the only place where I use getElementById. My main thought is that I'm doing the ID wrong and, for some reason, it's not registering with the DOM (though that doesn't explain why getElementById() still fails instead of returning null/undefined). Also, while I hope to eventually make this a FireFox add-on, I'm executing all of this through the FireBug console, so I don't know if that would affect it or not.
Any insights? I can change it to use getElementsByClassName (and it appears to work), but this is really frustrating me and I'd prefer not to use a messy work-around. (Actually, getElementsByName would be best, but I thought that getElementById would at least work.)
I need help putting together a script that will take all standard text on a page and translate it to another language (spanish or german).
So if I post this script on my blog at any given time (in the comment section) it will change the language for all viewers. Where do I start? Will this work on both FF and IE6/7?
i am working on java script and what exactly looking for is. whenever i select other in drop-down menu a text box should be displayed and whatever text entered in other text box should be saved in database when i submit the form. in addition to this in my script i have got two dropdown menus and both have other option in them.so i want a function which can be used to add other option to my both dropdown menus.
View 4 Replies View RelatedI am using this syntax to create an object:
Code:
carObject = {
model : "Volvo",
color : "blue",
outputModel : function()
{
alert("Modelname is: " + this.model)
}
};
carObject.outputModel(); // alerts "Modelname is Volvo"
Lets say i would like to add a new property, called brand, thats is equal to model. Can anyone please explain why this doesnt work?
Code:
carObject = {
model : "Volvo",
color : "blue",
brand : this.model,
outputModel : function()
{
alert("Modelname is: " + this.brand)
}
};
carObject.outputModel(); // alerts "Modelname is undefined"
I have reason to want to be able to change a Firefox stylesheet rule dynamically. I have found, doing google searches, sites which tell you how to create stylesheets dynamically or just add and delete rules, but none of these pages procedures have worked in my Firefox. Some have worked in Internet Explorer. Most have claimed to be cross browser. An example of one which I had high hopes would work can be found at this link.. The code they give you near the bottom of that page is posted below with the original background color changed to red and some text to see the background color put in the body of the page. In other words I pretty much just pasted the code found their in the head portion of my HTML page.
Attempting to troubleshoot why this code is not working if I use the old alert message method and put an alert message between the lines "var mysheet=document.styleSheets[0]" and the line "var totalrules=mysheet.cssRules? mysheet.cssRules.length : mysheet.rules.length" the mysheet variable region out as being "object CSSStyleSheet", however if I use the newer step through method with firebug it reads undefined. So I am totally baffled. Code:
I created the checkbox using this code:-
var chkbox = document.createElement('input');
chkbox.type = 'checkbox';
chkbox.name = 'disrow';
Now when i tried alert(document.forms['actionsForm'].disrow) I am getting undefined.
I'm creating some links with PHP and here is the code for that:
Code:
<br><a id="add_to_cart" href="add_to_cart.php?pic_id=<?php echo $resultsetnewpic['pic_id']; ?>" class="under_pic_cart">Add to Shopping Cart</a>
There is a while loop to keep adding them but wanted to keep it simple. So right now there are three links that get created. I'm trying to find out the value of these links so I can add things to a shopping cart for the user. I have the following jquery to do this:
Code:
$(function() {
$(".under_pic_cart").click(function(){
alert("it gets here");
[Code]....
This part works fine. However how can I get the href value of this and then once I have it basically split it after the = sign to get the value I'm really looking for?
I am getting a string with the value of the clicked button from an array and some other select field values that are listed in the same set of mysql results as the clicked button.At the end of the script the page is redirected to in the script mentioned page with following string:process.php?value=1&bs=2&ad=3&ns=4&wt=5&in=6
Is it possible to make locationstring variable global and in a single line in order to be able to use the full string in other scripts or is there another solution.
im currently working on a web app which uses heavy javascript. in one
of the functions, a simple array is created using "var admin_types =
new Array();". This array is not empty, it has a length of 0 but
contains one element with the name "clone" and the value
function () { var copy = {}; for (var i in this) { var value = this[i];
try { if (value != null && typeof (value) == "object" && value !=
window && !value.nodeType) { value.clone = Object.clone; copy[i] =
value.clone(); } else { copy[i] = value; } } catch (e) { copy[i] =
value; } } return copy; }
why does this element get created?? The weird thing is that i use a lot
of arrays and this is the only one that has that element.
i tried this in firefox 1.0, ie 5.5 and mozilla 1.7.1 and the element
is in the array for all of them...
I just wonder if there is a jquery plugin or something that enable me to create a html pagelayout with drag n drop.
Lets say i have a blank page with a div container, then i have a couple of layout elements that i can drag into that container, like 2 coulmn, 1 column, 3 column.
I hope you understund what i mean. something like sitefinitys template builder but in a light version.[URL]
Am developing MonthlyExpenses Project in which we have to enter details according to that date.
Date [IMG]datepickerimage[/IMG] Description Exptype Price
By clicking add button the dynamic row has to appear. But here , when I enter Date , the newdate is overwriting the previous one. New date is not appearing in new text box.
I have a small number of functions on an object and for every function I wish to make a different function that calls the original where the this can be passed as a parameter. I am making a library and this is a convenience method for people who don't know about call/apply.
Currently (one of) my function looks like this:
function _find(){
return find.apply(arguments[0],Array.prototype.slice.call(arguments,1));
}
However since my functions are in a object I was wondering if I could make a new array dynamically?
var func = {'find':find}, func_new={}; //this is just an example I don't have this part in my code
for(var attr in func)
func_new[attr] = Function('return '+attr+'.apply(arguments[0],Array.prototype.slice.call(arguments,1));');
I have a task to create tables dynamically, using the javascript DOM.
The current method uses a 1px x 1px IFRAME to loop through some data
generation stuff, and then call JS functions in the parent window to
generate the tables.
The basic idea is to add a table tag, with a thead and tbody, on the
main parent page, that has display:none set. This then becomes
display:block when there are rows to show. The rows themselves are
added directly to the visible tbody element using appendChild(). When
the results need to be refreshed, the tbody elements are removed, and
then added again.
This works well in most browsers, including Opera. However, Mac IE
always freezes when trying to generate the table, even for the first
time.
I have several different versions, and they all generate the same
issue. The tables I am creating are quite complex: multiple cells,
colspans, images, nested tables, roll over colours, styles etc. At
first, I believed it was an issue with creating images dynamically,
however it now seems that is not the case.
I have also tried creating the table and tbody tags using the DOM and
appending them to a div, but with no luck. I have also tried creating
the tables using a hidden object and then copying the innerHTML / nodes
across to the visible one. The various versions I have cover most
bases:
* using innerHTML to add content to the cells
* using the javascript DOM to create all elements and append them
* using a mixture of the both
If anybody has any feedback or suggestions then it would be really
appreciated, particularly related to the following:
* From your experience, is this realistically possible?
* Is the problem I'm experiencing related to the complexity or size
of the table I am trying to generate? If the table is simple text only,
with 2 or 3 columns and rows, then it does work.
* What is the best method to dynamically create tables and cell
content across browsers, and in Mac IE?
* Is the problem image related? Does anyone have experience of
creating images dynamically in tables in Mac IE? Do you use "new
image()" or createElement()? (using the small table sample, this was
possible using both methods, and also innerHTML on a cell).
I am running a program that makes > 50,000 ajax calls. Each time an ajax call is made a temporary function is created (by jQuery, not by me):
jQuery1620667739100754261_1311033524438
:function (a){g=[a]}
arguments
:null
[Code].....
So I end up with tens of thousands of these undefined global variables. I believe this is cause my script to fail and I am wondering if there is an easy way to fix this short of either editing the jquery library to delete these (can this be done?) orwritingmy own ajax function.... All other variables are getting smaller at the point of failure which isconsistentregardless of other changes made to the program.
I am testing on google chrome, but would like it to remain able to be used across updated browsers.