Made it create mechanisms variable if needed

Author: alan412

src/blocks/mrc_mechanism.ts

@@ -118,17 +118,16 @@ export const setup = function () {
   Blockly.Blocks[BLOCK_NAME] = MECHANISM_FUNCTION;
 }
 
-//TODO: This needs to cause our own init to create the mechanisms line
 export const pythonFromBlock = function (
   mechanismBlock: MechanismBlock,
   generator: ExtendedPythonGenerator,
 ) {
   if (mechanismBlock.mrcImportModule) {
     generator.addImport(mechanismBlock.mrcImportModule);
   }
+  generator.setHasMechanism();
   let code = 'self.mechanisms["' + mechanismBlock.getFieldValue('NAME') + '"] = '
     + mechanismBlock.getFieldValue('TYPE') + '('
-
   for (let i = 0; i < mechanismBlock.mrcArgs.length; i++) {
       const fieldName = 'ARG' + i;
       if(i != 0){

src/editor/extended_python_generator.ts

@@ -64,13 +64,19 @@ export class ExtendedPythonGenerator extends PythonGenerator {
       for (let i = 0; i < classVars.length; i++) {
           variableDefinitions += this.INDENT + this.getVariableName(classVars[i].getId()) + ' = None\n';
       }
+      if (this.context?.getHasMechanisms()){
+        variableDefinitions += this.INDENT + "self.mechanisms = []\n";
+      }
       return variableDefinitions;
   }
   getVariableName(name : string) : string{
     const varName = super.getVariableName(name);
     return "self." + varName;
   }
-
+  setHasMechanism() : void{
+    this.context?.setHasMechanism();
+  }
+  
   workspaceToCode(workspace: Blockly.Workspace, context: GeneratorContext): string {
     this.workspace = workspace;
     this.context = context;

src/editor/generator_context.ts

@@ -36,6 +36,9 @@ export class GeneratorContext {
   // Key is the mrc_class_method_def block's NAME field, value is the python method name.
   private classMethodNames: {[key: string]: string} = Object.create(null);
 
+  // Has mechanisms (ie, needs in init)
+  private hasMechanisms = false;
+
   setModule(module: commonStorage.Module | null) {
     this.module = module;
     this.clear();
@@ -44,6 +47,13 @@ export class GeneratorContext {
   clear(): void {
     this.clearExportedBlocks();
     this.clearClassMethodNames();
+    this.hasMechanisms = false;
+  }
+  setHasMechanism():void{
+    this.hasMechanisms = true;
+  }
+  getHasMechanisms():boolean{
+    return this.hasMechanisms;
   }
 
   getClassName(): string {