extending existing objects/classes

[hilukasz]

is there a way to extend existing classes? I am trying to add methods to the symbolItems class, but it doesn't seem to work. says it is not defined:

symbolItems.prototype.isIn = function(parentItem, runThis) {
//do something
}

[Larry G. Schneider]

Not as far as I know. AI scripting is pretty basic.

[Muppet_Mark-phjQ9l · Accepted solution]

You can extend the classes by prototyping it's something I have avoided so far but have seen other AI scripts where it has been used without issue though…

[Larry G. Schneider]

You're right, Mark. I found one of Carlos's scripts with a prototype class extension.

#target Illustrator
//  script.name = preview_CS4_CS5.V1.0.jsx;
//  script.description = previews the active artboard;
//  script.required = an open document;
//  script.parent = carlos canto // 8/30/11;
//  script.elegant = false;
//  script.credits = inspired by one of Mark Larsen's scripts where he used a snap shot of a selected object in the ScriptUI.
//                             Script made possible by the use of Marc Autret's prototype function to resize an image to fit its container.
//  notes: not the fastest script in town, it takes a couple of seconds to capture the screen. The bigger the artboard, the longer it takes.
//  Mac users: ************************** Press Esc key to dismiss *************************************** , windows too in fact.
if (app.documents.length > 0)
    {
        // thanks to Marc for writing this amazing function prototype
        Image.prototype.onDraw = function()
            { // written by Marc Autret
                // "this" is the container; "this.image" is the graphic
                if( !this.image ) return;
                var WH = this.size,
                wh = this.image.size,
                k = Math.min(WH[0]/wh[0], WH[1]/wh[1]),
                xy;
                // Resize proportionally:
                wh = [k*wh[0],k*wh[1]];
                // Center:
                xy = [ (WH[0]-wh[0])/2, (WH[1]-wh[1])/2 ];
                this.graphics.drawImage(this.image,xy[0],xy[1],wh[0],wh[1]);
                WH = wh = xy = null;
            }
        var idoc = app.activeDocument;
        var img = File('~/Desktop/tempCapture.png'); // image place holder
        var captureOpts = new ImageCaptureOptions; // declare capture options, needed to trun on anti-alias
        captureOpts.matte = true; // to give transparent areas some color. default is white.
        captureOpts.antiAliasing = true; // anti-alias the image
        idoc.imageCapture (img, idoc.artboards[idoc.artboards.getActiveArtboardIndex()].artboardRect,captureOpts); // capture the active artboard
        var w = new Window('dialog','Preview active Artboard - Press Esc key to close'); // create a dialog
        var scr = $.screens[0]; // array of screens, my laptop = screen[0]
        var width = scr.right-scr.left; // get max width
        var height = scr.bottom - scr.top; // get max height
        w.size = [width, height]; // size the window
        //var img = File.openDialog ('select file'); // debug test different images
        var imgFrame = w.add('image',undefined,img); // add image container
        imgFrame.helpTip = 'Coded by CarlosCanto';
        imgFrame.title = 'Press Esc key to close';
        imgFrame.titleLayout = { alignment: ['center', 'center'] };
        imgFrame.size = [width-100,height-80]; // size container, a tad smaller than the window
        w.show(); 
     }
 else 
    {
        alert ("there are no open documents to preview");
    }

[hilukasz]

hmm symbolItems doesn't seem to be extendable, unless they name it something else? any ideas how I could try to extend it. example above I gave does not work.

[moluapple]

Should be Class not Collection. Try this:

SymbolItem.prototype.isIn = function(parentItem, runThis) {
//do something
}