• Adobe After Effects Expressions

  Scripting Question

  Posted by Paul Benson

  

  on November 28, 2009 at 6:40 pm

  Trying to move up to scripting, and this is the closest forum I can find on the cow. I have seen something like this is a few scripts, and there is an example in the javascript tools guide for CS3. Essentially, the code is using a string as an array index. I’m not sure how this works. I’m thinking it is not a true array, so any insight is appreciated. Here is a code snippet which shows the values of all the properties of an object:
  
var f = new File ("myfile");
var props = f.reflect.properties;
for (var i = 0; i < props.length; i++) { $.writeln('this property ' + props[i].name + ' is ' + f[props[i].name]); }

  How does the f[props[i].name] get decoded? props[i].name is a string. Is this some alternate method to access object properties? Like if props[i].name = "path", then this will output f.path? That's what it implies to be doing, but I haven't seen this specifically addressed.

  Thanks,
  Pauley

  Paul Benson

  

  replied 16 years, 8 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Paul Benson

  November 28, 2009 at 7:02 pm

  Hmmm, well I’m still trying to wrap my head around it, but I did find this explanation.

  You can access ReflectionInfo objects in a Reflection object’s properties and methods arrays, by name or index:
  
obj = new String ("hi");
obj.reflect.methods[0];
obj.reflect.methods["indexOf"];


  I assume this is not unique to ReflectionInfo objects. I’m still trying to visualize this. Seems like a nice shortcut to get the the parameters/properties you want.

  Pauley
• 

  Dan Ebberts

  November 28, 2009 at 8:19 pm

  In JavaScript, objects are also associative arrays, which can be accessed using strings. There’s a lot of info out there on JavaScript objects and associative arrays. Google is your friend. 🙂

  Dan
• 

  Paul Benson

  November 28, 2009 at 8:32 pm

  Thanks Dan. The problem with google is that my search results always gave back links to basic array methods and properties. Now I know how to properly phrase my search with “associative arrays”. Your post should help me narrow down my search.

  Thanks,
  Pauley

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