downloadFile & repaint issue

[A Former User]

I'm using Server.downloadFile() to update .hxi's, and would like to have the Panel/Button display visual feedback but I'm having some difficulty with the download callback:

Server.downloadFile(library_updateURLs[this.data.index], {}, download_target, function() 
                {
                    if (this.data.finished)
                    {
                        Console.print("Finished");
                        this.data.downloading = false; //Swap SVG based on download state
                        expButton[this.data.index].repaint();
                    }
                });   

The Console Print line works, but the childpanel won't repaint. I assume it's a scope thing, but I've tried

this.repaint();
panel[i].repaint(); //The panels are in a loop already
panel[this.data.index].repaint(); //Where this.data.index is a forced variable of i

And none seem to work.

[A Former User]

Okay I see the issue, because the file download callback is on a different thread, the repaint outside the function calls before the download has finished.

But putting this.repaint() inside the download callback results in an error: function not found.

[DanH]

@iamlamprey not at my computer but pretty certain Dave made a vid about this. Also think there’s a tutorial project from Christoph somewhere too that has this in.

[Christoph Hart]

The this reference in the callback is not pointing to the panel, you need to pass it in as lambda.

[A Former User]

@Christoph-Hart said in downloadFile & repaint issue:

you need to pass it in as lambda.

Do you have an example of this handy? :)

[Christoph Hart]

I‘m on the go at the moment but if you search for lambda here in the forum you should find a post where I explain the feature.

[A Former User]

@Christoph-Hart I've found the thread but still can't get it repainting

Server.downloadFile(library_updateURLs[this.data.index], {}, download_target, function[this]() 
                {
                    if (this.data.finished)         
                    {
                        Console.print("Finished");      
                        this.data.downloading = false;              
                        this.repaint();
                    }              
                });     

I assume literally passing "this" in isn't the right approach lol

[Christoph Hart]

@iamlamprey No this is a reserved keyword which you can't pass as lambda.

But if you copy it as a normal variable, it should work. Try:

// I don't know if you're in an inline function or not, so adapt the keyword
// to match the scope
varOrLocal thisFromFunction = this;

Server.downloadFile(library_updateURLs[this.data.index], {}, download_target, function[thisFromFunction]() 
                {
                    if (this.data.finished)         
                    {
                        Console.print("Finished");      
                        this.data.downloading = false;              
                        thisFromFunction.repaint();
                    }              
                });     

[A Former User]

@Christoph-Hart Yep that got it, cheers!