Dynamically Create And Delete A Function At Runtime?
Jul 1, 2010
I'm using a 3rd party API that does asynchronous requests for me and directs response to a callback that I specify. Since my code can issue multiple requests concurrently I want some mechanism to match each response to the specific request e.g. attach a unique ID to be returned with the response. The 3rd party API does not allow me to attach any user context to the request so the only way I could figure out how to do this was to dynamically generate a callback function per request and embed the unique id in the body of that function. When the callback is invoked I can use the information to complete my handling of the response.
1) First of all if anybody has a better idea on how to achieve the above without dynamically generating script I'd be happy to hear it.2) Regardless of (1), if using my proposed method repeatedly I will be generating a lot of garbage over time, so I want to clean up after myself. Meaning, to delete the dynamic callback after it completes. Below is an example of how I wanted to do it, but it seems not to work:
I want to find a way of using canvas tags that are created at runtime. I went about this by trying to change the id of the tag, ONLY to find out that javascript did not like the fact that I was using numbers, even though I converted to String first... var count = 0; for (var item=0; item<20; item ++) { if (count%5==0){ document.write(" ||| "); } var canv = document.createElement("canvas"); canv.setAttribute('width',300); canv.setAttribute('height',300);
num = 505; aStr = num.toString(); // does NOT do the job for some reason !!!??? aStr = 'canvas'; // this works... canv.setAttribute('id',aStr); document.body.appendChild(canv); count += 1; } var C = document.getElementById(canv.getAttribute('id')); if (C.getContext) { makePlot(C); // does the plot to the canvas }
Can anyone suggest how to create an arbitrary object at runtime WITHOUT using the deprecated eval() function. The eval() method works ok (see below), but is not ideal.
function Client() { } Client.prototype.fullname = "John Smith"; var s = "Client"; eval("var o = new " + s + "();"); alert(o.fullname);
Note: I want the type name of the object to be represented as a string (in this case "Client" -- this is a non-negotiable requirement).
I also tried the following (which appears to fail):
function Client() { } Client.prototype.fullname = "John Smith"; var s = "Client"; var o = new Object(); o.construct = s; alert(o.fullname);
eval() is handy but not future-proof, so any suggestions would be welcome.
I have a code below where I have a table. I am adding rows dunamically on click of Add button where as If the user adds extra rows then the extra row must be deleted on press of the delete image at the last corner of the table.
How do I dynamically display images in javascript without hardcoding it. I cannot use php or any other language. My teacher said it is doable in javascript. so right now I have it hardcoded in:
var bellTowerArray = new Array(); bellTowerArray[0] = "bellTower01.jpg"; bellTowerArray[1] = "bellTower02.jpg"; bellTowerArray[2] = "bellTower03.jpg";
[Code]....
I have multiple categories of images so not just these two. I don't want to have to type in fountain# etc and stuff like that.
I'm kinda new in scripting, so this is why I ask the pro ppl.I'm trying to make an obfuscation with html+javascript(only these are allowed on mydisk.se), where:file1.html: displays some text, creates a cookie with a keyword, then after a few time a link appears to file2.html.file2.html part1: checks for the content of the cookie created, if it matches with the defined keyword, then deletes the cookie and shows some text part2: if cookie doesn't match, shows another text.
I'm wanting a table cell click event to remove and replace the table it was clicked on, however I'm finding that as it's deleting the original table object the actual running event code is being replaced and the function is bailing.how I can call the delete/refresh function from outside the event's function scope?
I try to make something where you add elements, and can delete elements later by calling a simple function. I simplyfied it right here: It works only to add the paragraphs, but the delete function doesn't work. Tried already to debug with an alert message after each rule... but the problem is with this rule I guess:
I am currently designing a on online shopping cart using cookies to store the customers selection. Basically on the shopping page, the user clicks a button which creates a cookie. When the user has finished all her shopping, she is taken to another page, where the articles, prices and subtotal is displayed using an HMTL table. I can create the cookies ok, but I am having trouble deleting the cookies. I have added a button to each line item in the table and the idea is that when the user clicks on the button, the line (and therefore the cookie) is deleted.The only problem is that nothing happens when the delete button is clicked!This is the script I have written to create and delete the cookies:
var cart=document.cookie; function getCookie(name){ var index = cart.indexOf(name + "=");
function asd() { var timeout = setInterval('alert('asd')', 3000); } function asd2() { // with this function I want to remove the interval of 3 seconds for variable timeout. }
I have variable timeout and with the second function asd2() I want to remove this variable.
jquery and a button delete, for remove rows of database.The problem is that I do not know how must input checkbox by clickable with click delete button sent to php code?my jquery code:
I have the following function to dynamically create an image (in this case a toolbox button):
Which works fine in IE8 and IE9, but in IE7 it refuses to pick up the style 'button'. I've even tried putting in btn.class='button' but JS throws up an error.
If I specify the style by btn.style.position='Absolute' it picks this up OK. However, it won't respond to the onclick event either.
I have heard that setAttribute is buggy with IE7, which is why I tried to specify each attribute directly.
The style sheet for class button is:
(BTW, no link to a website as this is local on my machine atm)
I've got 2 div's and the first one has a form in it.I want to create a table with the results of the form results in the second div. It currently erases the page to create the table
I don't use js too much, but for this job, I need to use it
I want to create a table dynamically. Here is the working code.[code]This table is always left alignment.Suppose I create another table which has 3x3 cells.Now I want to insert the first 2x2 table into the middle cell of the second table.I am not sure how to get the position of the cells and how to change the javascript code?
i'm sorry if this question has already been asked, but I searched for the term 'create element' on the jQuery Google Groups and didn't find the answer. I basically want to create html dynamically and be able to add it to my webpage. Suppose I have the following html:
Now in extension js file i want to check if check box is checked then create the variabel like CB1 (1 is the id) and the i want to assign value to this variable
i did something like this
[code ] //arrayLength is the no of check boxes for(var i= 0 ; i <arrayLength; i++) {
Code: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "(URL address blocked: See forum rules)"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title>
[Code]...
Basically, what I want to do is to dynamically create 5 instances of "emailRow" onto the web page making use of Javascript DOM. But have no success in getting it to work.
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <script type="text/javascript"> function emailRowContent(isSelected, emailAddress, severity)
I'm trying to dynamically create a canvas element. Later in the script it gets attached to the DOM, and this works fine if the last two lines are missing. I end up with a canvas element that is 3px wide and 100% of the containing div tall. However, the last two lines make it crash, with the error report 'canvases[i].fillRect is not a function'.
If I change the last two lines to: var drawing = canvases[i].getContext("2D"); drawing.fillRect(1,0,1,table_height);
It says 'drawing is null'. Something seems to be going wrong with the getContext bit, because setting the height and width work fine. It behaves the same if I append the canvas element to the DOM before trying to do the drawing as well. This is in FF4.0.1 with a xhtml1-strict.dtd doctype and valid html.
