refactor(compiler-cli): add function to identify model fields (angular#54252)

crisbeto · thePunderWoman · commit ab0c0cb83219 · 2024-02-07T16:36:02.000Z
Adds a function to the compiler to help us identify fields initialized to a `model`. PR Close angular#54252
diff --git a/packages/compiler-cli/src/ngtsc/annotations/directive/index.ts b/packages/compiler-cli/src/ngtsc/annotations/directive/index.ts
@@ -12,3 +12,4 @@ export * from './src/shared';
 export * from './src/input_function';
 export * from './src/output_function';
 export * from './src/query_functions';
+export * from './src/model_function';
diff --git a/packages/compiler-cli/src/ngtsc/annotations/directive/src/initializer_functions.ts b/packages/compiler-cli/src/ngtsc/annotations/directive/src/initializer_functions.ts
@@ -24,7 +24,7 @@ import {CORE_MODULE} from '../../common';
  */
 
 export type InitializerApiFunction =
-    'input'|'ɵoutput'|'output'|'viewChild'|'viewChildren'|'contentChild'|'contentChildren';
+    'input'|'model'|'ɵoutput'|'output'|'viewChild'|'viewChildren'|'contentChild'|'contentChildren';
 
 /**
  * Metadata describing an Angular class member that was recognized through
diff --git a/packages/compiler-cli/src/ngtsc/annotations/directive/src/model_function.ts b/packages/compiler-cli/src/ngtsc/annotations/directive/src/model_function.ts
@@ -0,0 +1,50 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import ts from 'typescript';
+
+import {ModelMapping} from '../../../metadata';
+import {ClassMember, ReflectionHost} from '../../../reflection';
+
+import {tryParseInitializerApiMember} from './initializer_functions';
+import {parseAndValidateInputAndOutputOptions} from './input_output_parse_options';
+
+/**
+ * Attempts to parse a model class member. Returns the parsed model mapping if possible.
+ */
+export function tryParseSignalModelMapping(
+    member: Pick<ClassMember, 'name'|'value'>, reflector: ReflectionHost,
+    isCore: boolean): ModelMapping|null {
+  const model = tryParseInitializerApiMember(['model'], member, reflector, isCore);
+  if (model === null) {
+    return null;
+  }
+
+  const optionsNode =
+      (model.isRequired ? model.call.arguments[0] : model.call.arguments[1]) as ts.Expression |
+      undefined;
+  const options =
+      optionsNode !== undefined ? parseAndValidateInputAndOutputOptions(optionsNode) : null;
+  const classPropertyName = member.name;
+  const bindingPropertyName = options?.alias ?? classPropertyName;
+
+  return {
+    input: {
+      isSignal: true,
+      transform: null,
+      classPropertyName,
+      bindingPropertyName,
+      required: model.isRequired,
+    },
+    output: {
+      isSignal: false,
+      classPropertyName,
+      bindingPropertyName: bindingPropertyName + 'Change',
+    }
+  };
+}
diff --git a/packages/compiler-cli/src/ngtsc/annotations/index.ts b/packages/compiler-cli/src/ngtsc/annotations/index.ts
@@ -10,7 +10,7 @@
 
 export {forwardRefResolver, getAngularDecorators, isAngularDecorator, NoopReferencesRegistry, ReferencesRegistry, ResourceLoader, ResourceLoaderContext} from './common';
 export {ComponentDecoratorHandler} from './component';
-export {DirectiveDecoratorHandler, queryDecoratorNames, QueryFunctionName, tryParseInitializerBasedOutput, tryParseSignalInputMapping, tryParseSignalQueryFromInitializer} from './directive';
+export {DirectiveDecoratorHandler, queryDecoratorNames, QueryFunctionName, tryParseInitializerBasedOutput, tryParseSignalInputMapping, tryParseSignalModelMapping, tryParseSignalQueryFromInitializer} from './directive';
 export {NgModuleDecoratorHandler} from './ng_module';
 export {InjectableDecoratorHandler} from './src/injectable';
 export {PipeDecoratorHandler} from './src/pipe';
diff --git a/packages/compiler-cli/src/ngtsc/metadata/src/api.ts b/packages/compiler-cli/src/ngtsc/metadata/src/api.ts
@@ -150,6 +150,21 @@ export type InputMapping = InputOrOutput&{
   transform: DecoratorInputTransform|null
 };
 
+/** Metadata for a model mapping. */
+export interface ModelMapping {
+  /** Information about the input declared by the model. */
+  input: InputOrOutput&{
+    /** Whether the input declared by the model is required. */
+    required: boolean;
+
+    /** Model inputs can't have transforms. Keeping it here for consistency. */
+    transform: null;
+  };
+
+  /** Information about the output implicitly declared by the model. */
+  output: InputOrOutput;
+}
+
 /** Metadata for an `@Input()` transform function. */
 export interface DecoratorInputTransform {
   /**
