refactor(change_detect): Share more codegen logic

Move more logic in our codegen into a shared util which is called by the
Jit & Prege change detector code.

Author: Tim Blasi

modules/angular2/src/change_detection/change_detection_jit_generator.ts

@@ -7,6 +7,7 @@ import {DirectiveIndex, DirectiveRecord} from './directive_record';
 
 import {ProtoRecord, RecordType} from './proto_record';
 import {CodegenNameUtil, sanitizeName} from './codegen_name_util';
+import {CodegenLogicUtil} from './codegen_logic_util';
 
 
 /**
@@ -24,13 +25,15 @@ var IS_CHANGED_LOCAL = "isChanged";
 var CHANGES_LOCAL = "changes";
 
 export class ChangeDetectorJITGenerator {
+  _logic: CodegenLogicUtil;
   _names: CodegenNameUtil;
   _typeName: string;
 
   constructor(public id: string, private changeDetectionStrategy: string,
               public records: List<ProtoRecord>, public directiveRecords: List<any>,
               private generateCheckNoChanges: boolean) {
     this._names = new CodegenNameUtil(this.records, this.directiveRecords, UTIL);
+    this._logic = new CodegenLogicUtil(this._names, UTIL);
     this._typeName = sanitizeName(`ChangeDetector_${this.id}`);
   }
 
@@ -206,7 +209,7 @@ export class ChangeDetectorJITGenerator {
     var oldValue = this._names.getFieldName(r.selfIndex);
     var newValue = this._names.getLocalName(r.selfIndex);
     var read = `
-      ${this._genUpdateCurrentValue(r)}
+      ${this._logic.genUpdateCurrentValue(r)}
     `;
 
     var check = `
@@ -232,80 +235,6 @@ export class ChangeDetectorJITGenerator {
     }
   }
 
-  _genUpdateCurrentValue(r: ProtoRecord): string {
-    var context = (r.contextIndex == -1) ? this._names.getDirectiveName(r.directiveIndex) :
-                                           this._names.getLocalName(r.contextIndex);
-    var newValue = this._names.getLocalName(r.selfIndex);
-    var argString = r.args.map((arg) => this._names.getLocalName(arg)).join(", ");
-
-    var rhs;
-    switch (r.mode) {
-      case RecordType.SELF:
-        rhs = context;
-        break;
-
-      case RecordType.CONST:
-        rhs = JSON.stringify(r.funcOrValue);
-        break;
-
-      case RecordType.PROPERTY:
-        rhs = `${context}.${r.name}`;
-        break;
-
-      case RecordType.SAFE_PROPERTY:
-        rhs = `${UTIL}.isValueBlank(${context}) ? null : ${context}.${r.name}`;
-        break;
-
-      case RecordType.LOCAL:
-        rhs = `${this._names.getLocalsAccessorName()}.get('${r.name}')`;
-        break;
-
-      case RecordType.INVOKE_METHOD:
-        rhs = `${context}.${r.name}(${argString})`;
-        break;
-
-      case RecordType.SAFE_INVOKE_METHOD:
-        rhs = `${UTIL}.isValueBlank(${context}) ? null : ${context}.${r.name}(${argString})`;
-        break;
-
-      case RecordType.INVOKE_CLOSURE:
-        rhs = `${context}(${argString})`;
-        break;
-
-      case RecordType.PRIMITIVE_OP:
-        rhs = `${UTIL}.${r.name}(${argString})`;
-        break;
-
-      case RecordType.COLLECTION_LITERAL:
-        rhs = `${UTIL}.${r.name}(${argString})`;
-        break;
-
-      case RecordType.INTERPOLATE:
-        rhs = this._genInterpolation(r);
-        break;
-
-      case RecordType.KEYED_ACCESS:
-        rhs = `${context}[${this._names.getLocalName(r.args[0])}]`;
-        break;
-
-      default:
-        throw new BaseException(`Unknown operation ${r.mode}`);
-    }
-    return `${newValue} = ${rhs}`;
-  }
-
-  _genInterpolation(r: ProtoRecord): string {
-    var res = "";
-    for (var i = 0; i < r.args.length; ++i) {
-      res += JSON.stringify(r.fixedArgs[i]);
-      res += " + ";
-      res += `${UTIL}.s(${this._names.getLocalName(r.args[i])})`;
-      res += " + ";
-    }
-    res += JSON.stringify(r.fixedArgs[r.args.length]);
-    return res;
-  }
-
   _genChangeMarker(r: ProtoRecord): string {
     return r.argumentToPureFunction ? `${this._names.getChangeName(r.selfIndex)} = true` : ``;
   }

modules/angular2/src/change_detection/codegen_facade.dart

@@ -0,0 +1,15 @@
+library angular2.src.change_detection.codegen_facade;
+
+import 'dart:convert' show JSON;
+
+/// Converts `funcOrValue` to a string which can be used in generated code.
+String codify(funcOrValue) => JSON.encode(funcOrValue).replaceAll(r'$', r'\$');
+
+/// Combine the strings of generated code into a single interpolated string.
+/// Each element of `vals` is expected to be a string literal or a codegen'd
+/// call to a method returning a string.
+/// The return format interpolates each value as an expression which reads
+/// poorly, but the resulting code is easily flattened by dart2js.
+String combineGeneratedStrings(List<String> vals) {
+  return '"${vals.map((v) => '\${$v}').join('')}"';
+}

modules/angular2/src/change_detection/codegen_facade.ts

@@ -0,0 +1,17 @@
+import {List} from 'angular2/src/facade/collection';
+
+/**
+ * Converts `funcOrValue` to a string which can be used in generated code.
+ */
+export function codify(obj: any): string {
+  return JSON.stringify(obj);
+}
+
+/**
+ * Combine the strings of generated code into a single interpolated string.
+ * Each element of `vals` is expected to be a string literal or a codegen'd
+ * call to a method returning a string.
+ */
+export function combineGeneratedStrings(vals: string[]): string {
+  return vals.join(' + ');
+}

modules/angular2/src/change_detection/codegen_logic_util.ts

@@ -0,0 +1,90 @@
+import {ListWrapper} from 'angular2/src/facade/collection';
+import {BaseException, Json} from 'angular2/src/facade/lang';
+import {CodegenNameUtil} from './codegen_name_util';
+import {codify, combineGeneratedStrings} from './codegen_facade';
+import {ProtoRecord, RecordType} from './proto_record';
+
+/**
+ * Class responsible for providing change detection logic for chagne detector classes.
+ */
+export class CodegenLogicUtil {
+  constructor(private _names: CodegenNameUtil, private _utilName: string) {}
+
+  /**
+   * Generates a statement which updates the local variable representing `protoRec` with the current
+   * value of the record.
+   */
+  genUpdateCurrentValue(protoRec: ProtoRecord): string {
+    var context = (protoRec.contextIndex == -1) ?
+                      this._names.getDirectiveName(protoRec.directiveIndex) :
+                      this._names.getLocalName(protoRec.contextIndex);
+    var argString =
+        ListWrapper.map(protoRec.args, (arg) => this._names.getLocalName(arg)).join(", ");
+
+    var rhs: string;
+    switch (protoRec.mode) {
+      case RecordType.SELF:
+        rhs = context;
+        break;
+
+      case RecordType.CONST:
+        rhs = codify(protoRec.funcOrValue);
+        break;
+
+      case RecordType.PROPERTY:
+        rhs = `${context}.${protoRec.name}`;
+        break;
+
+      case RecordType.SAFE_PROPERTY:
+        rhs = `${this._utilName}.isValueBlank(${context}) ? null : ${context}.${protoRec.name}`;
+        break;
+
+      case RecordType.LOCAL:
+        rhs = `${this._names.getLocalsAccessorName()}.get('${protoRec.name}')`;
+        break;
+
+      case RecordType.INVOKE_METHOD:
+        rhs = `${context}.${protoRec.name}(${argString})`;
+        break;
+
+      case RecordType.SAFE_INVOKE_METHOD:
+        rhs =
+            `${this._utilName}.isValueBlank(${context}) ? null : ${context}.${protoRec.name}(${argString})`;
+        break;
+
+      case RecordType.INVOKE_CLOSURE:
+        rhs = `${context}(${argString})`;
+        break;
+
+      case RecordType.PRIMITIVE_OP:
+        rhs = `${this._utilName}.${protoRec.name}(${argString})`;
+        break;
+
+      case RecordType.COLLECTION_LITERAL:
+        rhs = `${this._utilName}.${protoRec.name}(${argString})`;
+        break;
+
+      case RecordType.INTERPOLATE:
+        rhs = this._genInterpolation(protoRec);
+        break;
+
+      case RecordType.KEYED_ACCESS:
+        rhs = `${context}[${this._names.getLocalName(protoRec.args[0])}]`;
+        break;
+
+      default:
+        throw new BaseException(`Unknown operation ${protoRec.mode}`);
+    }
+    return `${this._names.getLocalName(protoRec.selfIndex)} = ${rhs};`;
+  }
+
+  _genInterpolation(protoRec: ProtoRecord): string {
+    var iVals = [];
+    for (var i = 0; i < protoRec.args.length; ++i) {
+      iVals.push(codify(protoRec.fixedArgs[i]));
+      iVals.push(`${this._utilName}.s(${this._names.getLocalName(protoRec.args[i])})`);
+    }
+    iVals.push(codify(protoRec.fixedArgs[protoRec.args.length]));
+    return combineGeneratedStrings(iVals);
+  }
+}