JavaScript

29-Jul-12 9:14

See my answer to your other question.

One of these days I'm going to think of a really clever signature.

ajax

Paresh Barad29-Jul-12 8:11

Paresh Barad

29-Jul-12 8:11

what is ajax?

Richard MacCutchan29-Jul-12 9:13

29-Jul-12 9:13

Try a Google search; you will find lots of information.

One of these days I'm going to think of a really clever signature.

Dispatch war rocket ajax to bring back his body[^]

J4amieC30-Jul-12 2:32

J4amieC

30-Jul-12 2:32

Pete O'Hanlon30-Jul-12 2:40

Pete O'Hanlon

30-Jul-12 2:40

I know that they are a rather good Dutch football team.

*pre-emptive celebratory nipple tassle jiggle* - Sean Ewington

"Mind bleach! Send me mind bleach!" - Nagy Vilmos

CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier

Is there any JavaScript libs with functions like DCT or FFT ?

enhzflep30-Jul-12 2:54

enhzflep

30-Jul-12 2:54

The name of an operation conducted by the US to protect western oil interests in Iran in 1953. Thanks ~~espen~~ Espen!

http://en.wikipedia.org/wiki/1953_Iranian_coup_d'etat#Execution_of_Operation_Ajax[^]

Though in the context you mean, it's a way of getting new info onto a (pre html5) webpage without reloading the whole page.

modified 31-Jul-12 7:16am.

twtsa26-Jul-12 15:48

twtsa

26-Jul-12 15:48

It's easy to crop,rotate,change colors of images.I want to use some senior image porcessing functions like DCT or FFT on HTML5 canvas? Is there any ready-made libs?

crop
<a href="http://www.webresourcesdepot.com/jquery-image-crop-plugin-jcrop">http://www.webresourcesdepot.com/jquery-image-crop-plugin-jcrop</a>[<a href="http://www.webresourcesdepot.com/jquery-image-crop-plugin-jcrop" target="_blank" title="New Window">^</a>]
rotate
<a href="http://code.google.com/p/jquery-rotate/">http://code.google.com/p/jquery-rotate/</a>[<a href="http://code.google.com/p/jquery-rotate/" target="_blank" title="New Window">^</a>]
change colors
<a href="http://github.com/mezzoblue/PaintbrushJS">http://github.com/mezzoblue/PaintbrushJS</a>[<a href="http://github.com/mezzoblue/PaintbrushJS" target="_blank" title="New Window">^</a>]
dct
<a href="http://en.wikipedia.org/wiki/Discrete_cosine_transform">http://en.wikipedia.org/wiki/Discrete_cosine_transform</a>[<a href="http://en.wikipedia.org/wiki/Discrete_cosine_transform" target="_blank" title="New Window">^</a>]
fft
<a href="http://en.wikipedia.org/wiki/Fft">http://en.wikipedia.org/wiki/Fft</a>[<a href="http://en.wikipedia.org/wiki/Fft" target="_blank" title="New Window">^</a>]

javascript dct fft

creating a object, passing it back to another function

jkirkerx23-Jul-12 7:55

jkirkerx

23-Jul-12 7:55

I'm toying around with objects for the first time, I'm kind of fuzzy about passing back an object to use in another function. It doesn't bomb, but my product object in load_Template is empty.

I looking for some clarity in understanding this.

function load_Template() {

    var exitCode = 0;
    $(document).ready(function () {

        var product = new Object();
        product = load_Structure_Product();
        alert(product.ID);

    });
    return exitCode;
}


function load_Structure_Product() {
    var product = new Object();
    $(document).ready(function () {
        product.ID = getParameterByName("cid");
        if (product.ID != 33) {
            product.PartNumber = "03-12E";
            product.ManPartNumber = "03-12E";
    });
    return product;
}

Re: creating a object, passing it back to another function

BobJanova23-Jul-12 23:28

Re: creating a object, passing it back to another function

23-Jul-12 23:28

Well of course it's empty, since you never assigned anything into it! You set up a document.ready handler which will later push some stuff into it, for some reason – since that function's already called inside a ready handler, I don't understand why you've done that. Just assign things directly into there!

function load_Structure_Product(){
 var product = { ID: getParameterByName("cid") };
 if(product.ID != 33) { // probably want a comment here explaining '33'
  product.PartNumber = "03-12E";
  product.ManPartNumber = "03-12E";
 }
 return product;
}

jkirkerx24-Jul-12 6:54

jkirkerx

24-Jul-12 6:54

Thanks,

I was wondering it I had to initialize the object like a structure in c++

The 33 was a mistake, suppose to be != ""

Let me try it today

var RVIPath = RVIPath || {};

fellathedog23-Jul-12 3:39

fellathedog

23-Jul-12 3:39

I am looking through JavaScript and searching the web to try to learn what it is doing. I see this as the first line of text. var RVIPath = RVIPath || {};
I know the || is a logical operator for OR. But the rest makes no sense to me.

BobJanova23-Jul-12 4:14

23-Jul-12 4:14

I'm not sure what you're looking at. But what that does is assigns a new blank object ( {} ) to that variable if it didn't previously exist. (Actually, it also does it if that variable contains 0, false, an empty string, null or possibly an empty object or array, as well as undefined. But I'm sure its purpose is to ensure it is assigned to something before further processing.)

fellathedog23-Jul-12 5:00

fellathedog

23-Jul-12 5:00

Thanks Bob.
But why the OR operand?
Here is the rest of the code:

// This function will open a new window with the URL of the Image requested.
OpenImageWindow = function (ImageViewer, RVIPath)
{

if (RVIPath != "XX") {

var hgt = screen.height - 20;
var wdt = screen.width * .5;
var lft = 1100;

var window_chrome = "toolbar=no,resizable=yes,height=" + hgt + ",width=" + wdt;

cas_window1 = window.open(RVIPath, "NewWindow", window_chrome);
cas_ window1.focus();
}

}

// This function will read thru a subfile and determine if the the Image field has a "Y" in it.
// If it does then it will set the field to " " and display the Scanner Images.
// If it does not then it sets the field to " " and leaves the URL blank.
DisplayScannerImage = function (elementsLength, imgCharField, imgImage, ScannerPath, startingID)
{
var startpoint = startingID;
var next = startpoint;

for (var i = 0; i < elementsLength; i++) {
var imgtext = document.getElementById(imgCharField + next);
var imgUrl = document.getElementById(imgImage + next);

if ($(imgtext).text() != 'Y') {
$(imgtext).text(' ');
$(imgUrl).hide();
}

if ($(imgtext).text() == 'Y') {
$(imgtext).text(' ');
$(imgUrl).attr('src', ScannerPath);
}
next = next + 1;
}

}

Richard MacCutchan23-Jul-12 5:17

23-Jul-12 5:17

fellathedog wrote:
But why the OR operand?

It's a shorthand way of saying:

JavaScript

if (RVIPath != NULL)
    RVIPath = RVIPath;
else
    RVIPath = new object;
// where else can be taken to mean or else

// or in optimized form
if (RVIPath == NULL)
    RVIPath = new object;

One of these days I'm going to think of a really clever signature.

fellathedog23-Jul-12 5:34

fellathedog

23-Jul-12 5:34

We had a missionary from Japan Sunday at church that said "the Japaneese language was created by the devil", in reference to it being hard to learn. Coming from a very safe comfortable environment to the web sometimes makes me think the same about JavaScript. I will learn this and be looking back and laughing at this comment. Thanks.

Richard MacCutchan23-Jul-12 5:41

23-Jul-12 5:41

fellathedog wrote:
I will learn this and be looking back and laughing at this comment.

As we all do from time to time ... Laugh | :laugh:

One of these days I'm going to think of a really clever signature.

BobJanova23-Jul-12 5:54

23-Jul-12 5:54

I don't know where the NULL comes from there. It is shorthand for

if(!RVIPath) RVIPath = {};

If RVIPath is assigned, but set to something which evaluates to false, it will be reassigned.

Richard MacCutchan23-Jul-12 7:06

23-Jul-12 7:06

Which is shorthand for

JavaScript

if(RVIPath == NULL) RVIPath = {};

The expression !object means object equals NULL.

JavaScript

// the expression if(!RVIPath) // is shorthand for if(!(RVIPath == NULL)) // or if(RVIPath != NULL)

One of these days I'm going to think of a really clever signature.

modified 23-Jul-12 13:48pm.

BobJanova23-Jul-12 23:25

23-Jul-12 23:25

Javascript is loosely typed. There's no guarantee that RVIPath was of type 'object' before arriving at this statement, and there are various other values it could have which would evaluate to 'false'.

Richard MacCutchan23-Jul-12 23:42

23-Jul-12 23:42

I was merely trying to explain syntax to OP, and I think my answer did that, and still holds true whether RVIPath is an object, a number or anything else.

One of these days I'm going to think of a really clever signature.

Andy Brummer9-Aug-12 10:38

Andy Brummer

9-Aug-12 10:38

I've gotten in the habit of doing !object with javascript because it is the least like any other programming language. Getting into the details of == and === in javascript is just too much of a PITA.

Curvature of the Mind now with 3D

Richard MacCutchan9-Aug-12 22:23

9-Aug-12 22:23

I have been doing that for nearly 30 years since I first read Kernighan & Ritchie[^]. I don't find Javascript that different, syntactically, from C or Java.

One of these days I'm going to think of a really clever signature.

Andy Brummer10-Aug-12 5:03

Andy Brummer

10-Aug-12 5:03

Funny, it must be one of my handicaps from learning C++ before C. I think the vogue at the time was to avoid shortcuts like that and avoid shortcuts like if (!x) for pointers.

Richard MacCutchan wrote:
I don't find Javascript that different, syntactically, from C or Java.

Once I got into the details of it, the common syntax made things more complicated for me than if it was more foreign. When I read javascript now every time I see x != null instead of !x or x !== null, I immediately leap to the conclusion that the author is still thinking that everything works like C# and there are probably subtle bugs lurking in the code. Using the full on javascript style is a message to my future self that the code was written when I better understood the way javascript works.

Curvature of the Mind now with 3D