An interface representing a channel which will have to execute some sort of
 program provided via its URI to compute the data it should return.

 If a channel implements this interface, the execution of the program in
 question will be restricted in the following ways:

 - If the channel does not have an owner principal, the program will not be
   executed at all, no matter what.  This is necessary because in this
   circumstance we have no way to tell whether script execution is allowed at
   all for the originating security context of this channel. 
 - If the channel has an owner principal, how it is executed is controlled by
   this interface.  However if the owner principal does not subsume the
   principal of the environment in which the program is to be executed the
   execution will be forced to happen in a sandbox.
[scriptable, uuid(33234b99-9588-4c7d-9da6-86b8b7cba565)]
interface nsIScriptChannel : nsISupports

Constants

 Possible ways of executing the program.


 Don't execute at all.
const unsigned long NO_EXECUTION = 0 
 Execute in a sandbox, no matter how the various principals involved are
 related to each other.
const unsigned long EXECUTE_IN_SANDBOX = 1 
 Execute against the target environment if the principals allow it.
const unsigned long EXECUTE_NORMAL = 2

Attributes

 Control whether the program should be executed synchronosly when
 the channel's AsyncOpen method is called or whether it should be
 executed asynchronously.  In both cases, any data that the
 channel returns will be returned asynchronously; the only thing
 this property affects is when the program executes.

 The default value of this property is TRUE.

 Setting this property after asyncOpen has been called on the
 channel has no effect.
attribute boolean executeAsync 
 Whether and how the program represented by this channel is to be executed.
 The default value if this property has never been set on this channel MUST
 be either EXECUTE_IN_SANDBOX or NO_EXECUTION.

 @throws NS_ERROR_INVALID_ARG when set to an unrecognized value.
attribute unsigned long executionPolicy