Question: How to determine declared function names?

[sandreas]

Hello,

thank you for jint - great project :-) I would like to determine, which functions are declared in a script. My approach would be to DIFF the existing global function names (like alert) with the ones after executing the script.

var engine = new Engine();
    
engine.Execute(@"
    function hello() { 
        
    };
");

Is there any way to get a list that contains hello as newly declared function?

Thank you.

[lahma]

You need to go through the AST tree produced by Esprima. Get Script instance from JavaScriptParser's Parse, then walk it recursive. Here's an example of that.

A simpler solution might be just inheriting from AstVisitor and override the VisitFunctionDeclaration, that will be called for every function.

[sandreas]

You need to go through the AST tree produced by Esprima. Get Script instance from JavaScriptParser's Parse, then walk it recursive. Here's an example of that.

Thank you for the quick response. Unfortunately this is way too complex for my use case, but I think I found another solution that might not require this at all.

A simpler solution might be just inheriting from AstVisitor and override the VisitFunctionDeclaration, that will be called for every function.

That might be a good option, if I cannot work around this problem the other way. Just for the sake of completeness: I thought it would be as easy as this: https://stackoverflow.com/questions/28367663/how-to-get-all-variables-and-functions-names-from-the-global-scope-in-jint

Thank you and keep up the good work.

[sandreas]

@lahma I found another possibility. Just for the sake of completeness, I use a combination and function names and global namespace injection for my use case (tone is a C# command line audio tagger):

function musicbrainz(metadata, parameters) {
    // ...
}
tone.RegisterTagger("musicbrainz");

• publish tone in the global namespace: https://github.com/sandreas/tone/blob/a0a99eb61bf4c44a07d2f8b44513e0721f240ff2/tone/Program.cs#L124
• definition of the published RegisterTagger method: https://github.com/sandreas/tone/blob/a0a99eb61bf4c44a07d2f8b44513e0721f240ff2/tone/Services/JavaScriptApi.cs#L43
• ScriptTagger class handling the call of the function via Engine.Invoke: https://github.com/sandreas/tone/blob/a0a99eb61bf4c44a07d2f8b44513e0721f240ff2/tone/Metadata/Taggers/ScriptTagger.cs#L15

Works pretty good. Now I can create custom audio tagger logic via JavaScript. Thanks for that :-)

For more information see: https://github.com/sandreas/tone#custom-scripted-taggers-experimental