Subj : Re: Rhino, extracting functions from a script?
To   : netscape.public.mozilla.jseng
From : Igor Bukanov
Date : Sun Aug 15 2004 06:13 pm

Laurens wrote:
> Hi,
> 
> 
> Is it possible to extract Functions from a given Script?
> 
> I know it's possible to compile source code to a Function using 
> Context.compileFunction. What I want, however, is to compile a 
> JavaScript file containing multiple functions and reuse the Functions 
> instances across different Scopes in my application. More specifically, 
> I want to offer my users the ability to create a custom script with 
> common utility functions. These functions should be available whenever a 
> script runs.

Context.compileString or Context.compileReader compile script and all 
function definition it contains to internal form. When you run this 
script via Script.exec(cx, scope), it will wrap the internal 
presentations into Function objects (fast operation) and put then into 
scope. Then it will execute the rest of script code if any.

For example, if you have a script containing just function definitions 
like in:

function f1() { ... }
function f2() { ... }
  ...
function f3() { ... }

then whenever you execute Script.exec(cx, scope), Rhino will create 
properties named "f1", "f2", ..., "fN" in the scope object with proper 
Function objects.

So if you simply run Script.exec before executing the rest of code, that 
should allow to access precompiled functions.

Regards, Igor

.