My goal is to create button on panel that if I push it, will change scale of currently selected clip.
Change it...to what? What's the entire workflow, you're trying to support?
Also, "Allow panels to register for notification when the timeline selection changes" is a pretty popular API feature request; I'll add your vote.
What is going on behind-the-scenes with evalScript?
Yes, carefully-defended trade secret...
[Looks both ways, leans in conspiratorially...]
It passes the script...to ExtendScript engine...where it's evaluated.
Sssssh!
Web socket connections are totally possible between panels, in JavaScript; I've not heard of anyone using a web socket connection, between JavaScript and ExtendScript.
<?xml version="1.0" encoding="UTF-8"?> <!-- /************************************************************************* * ADOBE CONFIDENTIAL * ___________________ * * Copyright 2014 Adobe * All Rights Reserved. * * NOTICE: Adobe permits you to use, modify, and distribute this file in * accordance with the terms of the Adobe license agreement accompanying * it. If you have received this file from a source other than Adobe, * then your use, modification, or distribution of it requires the prior * written permission of Adobe. **************************************************************************/ --> <ExtensionManifestVersion="5.0"ExtensionBundleId="com.adobe.PProPanel"ExtensionBundleVersion="11.1" ExtensionBundleName="Premiere Pro sample panel" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <ExtensionList> <ExtensionId="com.adobe.PProPanel"Version="10.3.0"/> </ExtensionList> <ExecutionEnvironment> <HostList> <HostName="PPRO"Version="9.0"/> </HostList> <LocaleList> <LocaleCode="All"/> </LocaleList> <RequiredRuntimeList> <RequiredRuntimeName="CSXS"Version="6.0"/> </RequiredRuntimeList> </ExecutionEnvironment>
cs.evalScript() is an asyncronous call, meaning it will wait until it receives a reply from your jsx script before setting ‘result’ and executing the callback function your evalScript.
While asyncronous functions wait patiently before executing their callbacks, that ‘waiting’ does not halt execution of the next line of code, which in your case is the ‘outside’ alert.
So your code will execute your second ‘outside’ alert first and your first ‘in evalscript’ second.
In evalScript function the variable get's the string from jsx function but when I want to use it outside I get empty string again.
Also I get the alert outside evalScript first in order. Why this happens?
Does anyone know why this happens and how to fix this?
As others have pointed out, CSInterface.evalScript is an asynchronous* function.
* There is currently a bug on Adobe apps in macOS that causes evalScript to runsynchronously. This doesn't help you, however, because the callback still gets scheduled to occur after the current context completes.
Here's how your code is evaluated:
Call to evalScript sends a request to process the code you send it.
Your "outside" alert is triggered. The capturedvariable variable is still the empty string.
The Panel (JS) processing (started via some callback, e.g. button click callback) completes.
The ExtendScript (JSX) context is started and begins to process the request you sent it.
The script you passed to ExtendScript (JSX) is processed, generating the return value you are interested in (coerces it to a string).
The ExtendScript (JSX) context sends a request to process the string to the JS using the callback you specified.
The panel (JS) context runs the callback that you provided to evalScript and only now will it have the chance to set the capturedvariable variable to the string that your JSX code produced. Your "inside" alert is triggered.
What you really want to do is run your "outside" alert after the "inside" code has had a chance to run. To do this you need to somehow get #2 to occur after #7. This is where the setTimeout function comes in handy. Try this:
(function () {
var cs = new CSInterface();
var variable = "";
cs.evalScript('"string"', function(result) {
variable = result;
alert("variable in evalScript =" + variable);
});
setTimeout(() => {alert("variable in outside = " + variable);}, 0);
}());
Note that I got rid of the special JSX-side function that simply returns "string". Rather, I just made the evalScript simply return that directly.
The important part is line 8. That schedules the anonymous, inline function to be called at a later date (the 0 at the end means "as soon as possible" - if you had heavy script in your JSX [on applications running in Windows] then you might need to delay even further with larger numbers). Honestly, though, the correct thing to do is simply trigger another function call that makes use of that captured variable from within the function itself. Both the callback passed to evalScript and the one passed to setTimeoutcapture a reference to the same variable instance which means that when one changes, both do. It's merely a matter of determining which callback is triggered earlier.
Most of this topic went over my head. Is there a way to get information from the jsx file back to the js script in your html file? I am trying to use a folder picker in the form of:
var fPath = decodeURIComponent(Folder.selectDialog("Choose the output directory"));
I can get the path and alert from the jsx file but I cannot seem to set it to a variable to display to the user in a panel field. Is this possible? Thanks
Hi, thanks so much for the reply. I am still having no luck with what I am trying to accomplish. So that function is similar to the one I have created. Using the one you show as an example, how would I get the userName (returned) variable to be persistent so that I could update a field in my panel with its value? Thanks
> Using the one you show as an example, how would I get the userName (returned) variable to be persistent so that I could update a field in my panel with its value?
If you look at the JavaScript side, you'll see that getUserName is called both from within the panel's OnLoaded() function, and when PProPanel is copying presets into the user's directory, and needs the user name.
In both cases, the returned name is passed to the callback function specified, when invoking the ExtendScript. That callback function displays the user's name in the panel.
Thank you again, all that you have posted help me understand better. I see what you are talking about now. I think my problem is that I do not understand how to work with the "when" thing are happening. I noticed that the examples are all when things are initialized, meaning when the script starts up. I am trying to do something after the script has already started. I would like to have a field and browse button and let a user of the script choose a directory, or even manually type on in. If I start my script reporting some system variable it is fine. However, I when I refer to that variable again it is always undefined. Thanks.
Once that panel is up displaying the users name how could you refer to that property in the JavaScript file? Is there then an property that can be used again. I cannot seem to call it again. All I recieve is undefined.Thanks
Take a look at this JavaScript function, in PProPanel; it receives the userName returned by the ExtendScript function, and modifies the innerHTML of the object displaying the user name, in the panel.
I have changed the code so many times it might be off now. But my point is that after the first load of the panel I am not able to get the value of the Folder.selectDialog("Choose the output directory"). Thanks
That worked like a charm... funny I thought I tried to do this already. The first time @bbb_999 sugested the code in the PProPanel's example (scratching my head ). However that is great to know. I really thank you guys for suggesting so many helpful things. What @bbb directed me to is a big help also in building better scripts. Once again @sberic Thank you so much!
1 Correct answer
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). However that is great to know. I really thank you guys for suggesting so many helpful things. What @bbb directed me to is a big help also in building better scripts. Once again @sberic Thank you so much! 
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