/// <summary>
/// This routine loads a script (if it has not already been loaded),
/// and sets up globals for the script. The script needs to be safe to
/// have its entrypoint called from OBJECT_INVALID for this function to
/// work properly.
/// </summary>
/// <param name="ScriptName">Supplies the name of the script to load.</param>
/// <param name="ForceLoadScript">If true, forcibly attempt to load
/// the script.</param>
/// <param name="CallerScript">Supplies the script object owned by the
/// caller.</param>
/// <returns>The script object for the newly loaded script. On failure
/// an exception is raised.</returns>
public static IGeneratedScriptProgram LoadScript(string ScriptName, bool ForceLoadScript, CLRScriptBase CallerScript)
{
string AssemblyName = String.Format("NWScriptAsm_{0}, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null", ScriptName);
string TypeName = String.Format("NWScript.JITCode.{0}.ScriptProgram", ScriptName);
Assembly ScriptAssembly;
IGeneratedScriptProgram ScriptObject;
Type ScriptObjectType;
MethodInfo NWScriptInitGlobals;
//
// Check if the script is already loaded. If so, use the existing
// script assembly.
//
ScriptAssembly = (from LoadedAsm in AppDomain.CurrentDomain.GetAssemblies()
where LoadedAsm.FullName == AssemblyName
select LoadedAsm).FirstOrDefault();
if (ScriptAssembly == null && ForceLoadScript)
{
//
// The assembly is not yet loaded. Force it to be loaded via
// a dummy ExecuteScript call.
//
CallerScript.ExecuteScript(ScriptName, CLRScriptBase.OBJECT_INVALID);
ScriptAssembly = (from LoadedAsm in AppDomain.CurrentDomain.GetAssemblies()
where LoadedAsm.FullName == AssemblyName
select LoadedAsm).FirstOrDefault();
}
if (ScriptAssembly == null)
{
throw new ApplicationException("Could not load script " + ScriptName);
}
//
// Now that the script assembly is loaded, we can create a script
// object out of the script for our own use. The script object
// encapsulates a private set of global variables for the target
// script.
//
ScriptObject = (IGeneratedScriptProgram)ScriptAssembly.CreateInstance(
TypeName,
false,
BindingFlags.CreateInstance,
null,
new object[] { CallerScript.ScriptHost.Intrinsics, CallerScript.ScriptHost.Host },
null,
null);
ScriptObjectType = ScriptObject.GetType();
//
// If the script had global variables, call the global variable
// initializer on the script now. This will set the script object
// up into a state as though we created all the global variables,
// but stopped just before main() or StartingConditional().
//
NWScriptInitGlobals = ScriptObjectType.GetMethod("NWScriptInitGlobals");
if (NWScriptInitGlobals != null)
{
NWScriptInitGlobals.Invoke(ScriptObject, null);
}
//
// The private script object is ready to use. Return the instance
// of the script that we had created.
//
return(ScriptObject);
}