jsContext snippet

let script: JSValue = jsContext.objectForKeyedSubscript("getImageURL")
[jsContext callWithArguments:@["FirstParam",^(NSString* callbackValue) {
  NSLog(@"Got a value: %@",callbackValue)
}]

basically I have a javascript function that looks like this:

	function getImageURL(object, callback) {
	object.executeActionById("takeScreenshot");
        object.onScreenshotReady(function(imageName) {
            alert(imageName);
            callback(imageName);
        });
      };
            
And all I really want is imageName on the iOS side. So I'm trying to call the callback part of it on iOS and get imageName.
onScreenshotReady is async so I need to wait for it to finish before I get my imageName. So I created a callback within it

I added the exceptionHandler to see if I get any errors:

And turns out I did. "widget" was not being passed along so the function was executing

object.executeActionById("takeScreenshot");
object.onScreenshotReady(function(imageName) ....

instead of
widget.executeActionById("takeScreenshot");
widget.onScreenshotReady(function(imageName) ....

So since I actually don't need to pass that parameter from iOS. I just hardcoded it directly. so my function became:

        function getImageURL(callback) {
            widget.executeActionById("takeScreenshot");
            widget.onScreenshotReady(function(imageName) {
              callback(imageName);
            });
        };

and on iOS side i did:

        let args = [unsafeBitCast(callback, AnyObject.self)]

        jsContext.objectForKeyedSubscript("getImageURL").callWithArguments(args)

And works exactly as expected.

Many many thanks for feedback. Spent two days on this pesky issue. Now onto the next

HI @acegreen,

How can I save an image to my local("Downloads") without using the snapshot url from tradingview?

Hi @acegreen,
In addition to my first question, how can I create a method that will not generate an image on tradingview, but generating a base64 image and saving it to my local directory.

Thanks in advance..=