Is there a method or function to list all the properties

Question

I'm looking for a method that's similar to Python's dir(x) which lists all the properties of an object. I'm looking to use this on After Effects Objects.

Answer 1

You can use a for...in loop: for (var key in myObj) if (myObj.hasOwnProperty(key)){ ...}
But in ExtendScript there are also Reflection and ReflectionInfo objects. Those are not documented in the After Effects Scripting Guide but in the JavaScript Tools Guide (common to all Adobe scriptable apps).
For any ExtendScript object o you can query its reflection object. o.reflect is an object with properties and methods:
"properties" : an array listing all properties in o. Each entry is a ReflectionInfo object.
"methods" : an array listing all methods in o. Each entry is a ReflectionInfo object.
"name" : the class name of the object
"help" and "description" : some strings supposed to give some hint about the objects but those fields are invariably empty...
"find" : a method to find a specific property or method by its name
For what a ReflectionInfo looks like, see the JavaScript Tools Guide. (The main properties are "name", "dataType", "type")
For instance, if o is a layer position property:
o.reflect.methods = array of ReflectionInfo corresponding to all "ADBE Position" methods
o.reflect.find("setValue") => ReflectionInfo corresponding to the method "setValue"
o.reflect.find("setValue").name : "setValue"
o.reflect.find("setValue").arguments.length : 0     // SHOULD BE 1 ... arguments are not filled in :-(
Xavier.