System.Xml.Xsl.XsltOld.VariableAction.Execute C# (CSharp) Method

        internal override void Execute(Processor processor, ActionFrame frame) {
            Debug.Assert(processor != null && frame != null && frame.State != ValueCalculated);
            object value = null;

            switch(frame.State) {
            case Initialized:
                if (IsGlobal) {
                    if (frame.GetVariable(this.varKey) != null) { // This var was calculated already
                        frame.Finished();
                        break;
                    }
                    stylesheetid = -1; // Mark that variable is in use to catch loops in global variables;
                }
                // If this is a parameter, check whether the caller has passed the value
                if (this.varType == VariableType.GlobalParameter) {
                    value = processor.GetGlobalParameter(this.name);
                } else if (this.varType == VariableType.LocalParameter) {
                    value = processor.GetParameter(this.name);
                }
                if (value != null) {
                    goto case ValueCalculated;
                }

                // If value was not passed, check the 'select' attribute
                if (this.selectKey != Compiler.InvalidQueryKey) {
                    value = processor.RunQuery(frame, this.selectKey);
                    goto case ValueCalculated;
                }

                // If there is no 'select' attribute and the content is empty, use the empty string
                if (this.containedActions == null) {
                    value = string.Empty;
                    goto case ValueCalculated;
                }

                // RTF case
                NavigatorOutput output = new NavigatorOutput(this.baseUri);
                processor.PushOutput(output);
                processor.PushActionFrame(frame);
                frame.State = ProcessingChildren;
                break;

            case ProcessingChildren:
                RecordOutput recOutput = processor.PopOutput();
                Debug.Assert(recOutput is NavigatorOutput);
                value = ((NavigatorOutput)recOutput).Navigator;
                goto case ValueCalculated;

            case ValueCalculated:
                Debug.Assert(value != null);
                frame.SetVariable(this.varKey, value);
                frame.Finished();
                break;

            default:
                Debug.Fail("Invalid execution state inside VariableAction.Execute");
    		    break;
            }
        }