feat(ivy): support generating view and content queries (#22330)

PR Close #22330

packages/compiler/src/output/abstract_js_emitter.ts

@@ -82,8 +82,11 @@ export abstract class AbstractJsEmitterVisitor extends AbstractEmitterVisitor {
     return null;
   }
   visitDeclareVarStmt(stmt: o.DeclareVarStmt, ctx: EmitterVisitorContext): any {
-    ctx.print(stmt, `var ${stmt.name} = `);
+    ctx.print(stmt, `var ${stmt.name}`);
-    stmt.value.visitExpression(this, ctx);
+    if (stmt.value) {
+      ctx.print(stmt, ' = ');
+      stmt.value.visitExpression(this, ctx);
+    }
     ctx.println(stmt, `;`);
     return null;
   }

packages/compiler/src/output/output_ast.ts

@@ -756,14 +756,14 @@ export abstract class Statement {
 export class DeclareVarStmt extends Statement {
   public type: Type|null;
   constructor(
-      public name: string, public value: Expression, type?: Type|null,
+      public name: string, public value?: Expression, type?: Type|null,
       modifiers: StmtModifier[]|null = null, sourceSpan?: ParseSourceSpan|null) {
     super(modifiers, sourceSpan);
-    this.type = type || value.type;
+    this.type = type || (value && value.type) || null;
   }
   isEquivalent(stmt: Statement): boolean {
     return stmt instanceof DeclareVarStmt && this.name === stmt.name &&
-        this.value.isEquivalent(stmt.value);
+        (this.value ? !!stmt.value && this.value.isEquivalent(stmt.value) : !stmt.value);
   }
   visitStatement(visitor: StatementVisitor, context: any): any {
     return visitor.visitDeclareVarStmt(this, context);
@@ -1087,11 +1087,9 @@ export class AstTransformer implements StatementVisitor, ExpressionVisitor {
   }
 
   visitDeclareVarStmt(stmt: DeclareVarStmt, context: any): any {
+    const value = stmt.value && stmt.value.visitExpression(this, context);
     return this.transformStmt(
-        new DeclareVarStmt(
+        new DeclareVarStmt(stmt.name, value, stmt.type, stmt.modifiers, stmt.sourceSpan), context);
-            stmt.name, stmt.value.visitExpression(this, context), stmt.type, stmt.modifiers,
-            stmt.sourceSpan),
-        context);
   }
   visitDeclareFunctionStmt(stmt: DeclareFunctionStmt, context: any): any {
     return this.transformStmt(
@@ -1275,7 +1273,9 @@ export class RecursiveAstVisitor implements StatementVisitor, ExpressionVisitor
   }
 
   visitDeclareVarStmt(stmt: DeclareVarStmt, context: any): any {
-    stmt.value.visitExpression(this, context);
+    if (stmt.value) {
+      stmt.value.visitExpression(this, context);
+    }
     if (stmt.type) {
       stmt.type.visitType(this, context);
     }

packages/compiler/src/output/output_interpreter.ts

@@ -95,7 +95,8 @@ class StatementInterpreter implements o.StatementVisitor, o.ExpressionVisitor {
   debugAst(ast: o.Expression|o.Statement|o.Type): string { return debugOutputAstAsTypeScript(ast); }
 
   visitDeclareVarStmt(stmt: o.DeclareVarStmt, ctx: _ExecutionContext): any {
-    ctx.vars.set(stmt.name, stmt.value.visitExpression(this, ctx));
+    const initialValue = stmt.value ? stmt.value.visitExpression(this, ctx) : undefined;
+    ctx.vars.set(stmt.name, initialValue);
     if (stmt.hasModifier(o.StmtModifier.Exported)) {
       ctx.exports.push(stmt.name);
     }

packages/compiler/src/output/ts_emitter.ts

@@ -161,8 +161,10 @@ class _TsEmitterVisitor extends AbstractEmitterVisitor implements o.TypeVisitor
     }
     ctx.print(stmt, ` ${stmt.name}`);
     this._printColonType(stmt.type, ctx);
-    ctx.print(stmt, ` = `);
+    if (stmt.value) {
-    stmt.value.visitExpression(this, ctx);
+      ctx.print(stmt, ` = `);
+      stmt.value.visitExpression(this, ctx);
+    }
     ctx.println(stmt, `;`);
     return null;
   }

packages/compiler/src/render3/r3_identifiers.ts

@@ -110,5 +110,8 @@ export class Identifiers {
 
   static definePipe: o.ExternalReference = {name: 'ɵdefinePipe', moduleName: CORE};
 
+  static query: o.ExternalReference = {name: 'ɵQ', moduleName: CORE};
+  static queryRefresh: o.ExternalReference = {name: 'ɵqR', moduleName: CORE};
+
   static NgOnChangesFeature: o.ExternalReference = {name: 'ɵNgOnChangesFeature', moduleName: CORE};
 }

packages/compiler/src/render3/r3_pipe_compiler.ts

@@ -24,7 +24,7 @@ export function compilePipe(
       {key: 'type', value: outputCtx.importExpr(pipe.type.reference), quoted: false});
 
   // e.g. factory: function MyPipe_Factory() { return new MyPipe(); },
-  const templateFactory = createFactory(pipe.type, outputCtx, reflector);
+  const templateFactory = createFactory(pipe.type, outputCtx, reflector, []);
   definitionMapValues.push({key: 'factory', value: templateFactory, quoted: false});
 
   // e.g. pure: true

packages/compiler/src/render3/r3_view_compiler.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {CompileDirectiveMetadata, CompilePipeSummary, CompileTokenMetadata, CompileTypeMetadata, flatten, identifierName, rendererTypeName, tokenReference, viewClassName} from '../compile_metadata';
+import {CompileDirectiveMetadata, CompilePipeSummary, CompileQueryMetadata, CompileTokenMetadata, CompileTypeMetadata, flatten, identifierName, rendererTypeName, tokenReference, viewClassName} from '../compile_metadata';
 import {CompileReflector} from '../compile_reflector';
 import {BindingForm, BuiltinConverter, BuiltinFunctionCall, ConvertPropertyBindingResult, EventHandlerVars, LocalResolver, convertActionBinding, convertPropertyBinding, convertPropertyBindingBuiltins} from '../compiler_util/expression_converter';
 import {ConstantPool, DefinitionKind} from '../constant_pool';
@@ -47,7 +47,7 @@ export function compileDirective(
       {key: 'type', value: outputCtx.importExpr(directive.type.reference), quoted: false});
 
   // e.g. `factory: () => new MyApp(injectElementRef())`
-  const templateFactory = createFactory(directive.type, outputCtx, reflector);
+  const templateFactory = createFactory(directive.type, outputCtx, reflector, directive.queries);
   definitionMapValues.push({key: 'factory', value: templateFactory, quoted: false});
 
   // e.g 'inputs: {a: 'a'}`
@@ -108,9 +108,15 @@ export function compileComponent(
   }
 
   // e.g. `factory: function MyApp_Factory() { return new MyApp(injectElementRef()); }`
-  const templateFactory = createFactory(component.type, outputCtx, reflector);
+  const templateFactory = createFactory(component.type, outputCtx, reflector, component.queries);
   definitionMapValues.push({key: 'factory', value: templateFactory, quoted: false});
 
+  // e.g `hostBindings: function MyApp_HostBindings { ... }
+  const hostBindings = createHostBindingsFunction(component.type, outputCtx, component.queries);
+  if (hostBindings) {
+    definitionMapValues.push({key: 'hostBindings', value: hostBindings, quoted: false});
+  }
+
   // e.g. `template: function MyComponent_Template(_ctx, _cm) {...}`
   const templateTypeName = component.type.reference.name;
   const templateName = templateTypeName ? `${templateTypeName}_Template` : null;
@@ -118,7 +124,8 @@ export function compileComponent(
   const templateFunctionExpression =
       new TemplateDefinitionBuilder(
           outputCtx, outputCtx.constantPool, reflector, CONTEXT_NAME, ROOT_SCOPE.nestedScope(), 0,
-          component.template !.ngContentSelectors, templateTypeName, templateName, pipeMap)
+          component.template !.ngContentSelectors, templateTypeName, templateName, pipeMap,
+          component.viewQueries)
           .buildTemplateFunction(template, []);
   definitionMapValues.push({key: 'template', value: templateFunctionExpression, quoted: false});
 
@@ -296,7 +303,7 @@ class TemplateDefinitionBuilder implements TemplateAstVisitor, LocalResolver {
       private reflector: CompileReflector, private contextParameter: string,
       private bindingScope: BindingScope, private level = 0, private ngContentSelectors: string[],
       private contextName: string|null, private templateName: string|null,
-      private pipes: Map<string, CompilePipeSummary>) {
+      private pipes: Map<string, CompilePipeSummary>, private viewQueries: CompileQueryMetadata[]) {
     this._valueConverter = new ValueConverter(
         outputCtx, () => this.allocateDataSlot(), (name, localName, slot, value) => {
           bindingScope.set(localName, value);
@@ -353,6 +360,32 @@ class TemplateDefinitionBuilder implements TemplateAstVisitor, LocalResolver {
       }
     }
 
+    // Define and update any view queries
+    for (let query of this.viewQueries) {
+      // e.g. r3.Q(0, SomeDirective, true);
+      const querySlot = this.allocateDataSlot();
+      const predicate = getQueryPredicate(query, this.outputCtx);
+      const args = [
+        /* memoryIndex */ o.literal(querySlot, o.INFERRED_TYPE),
+        /* predicate */ predicate,
+        /* descend */ o.literal(query.descendants, o.INFERRED_TYPE)
+      ];
+
+      if (query.read) {
+        args.push(this.outputCtx.importExpr(query.read.identifier !.reference));
+      }
+      this.instruction(this._creationMode, null, R3.query, ...args);
+
+      // (r3.qR(tmp = r3.ɵld(0)) && (ctx.someDir = tmp));
+      const temporary = this.temp();
+      const getQueryList = o.importExpr(R3.load).callFn([o.literal(querySlot)]);
+      const refresh = o.importExpr(R3.queryRefresh).callFn([temporary.set(getQueryList)]);
+      const updateDirective = o.variable(CONTEXT_NAME)
+                                  .prop(query.propertyName)
+                                  .set(query.first ? temporary.prop('first') : temporary);
+      this._bindingMode.push(refresh.and(updateDirective).toStmt());
+    }
+
     templateVisitAll(this, asts);
 
     const creationMode = this._creationMode.length > 0 ?
@@ -589,7 +622,7 @@ class TemplateDefinitionBuilder implements TemplateAstVisitor, LocalResolver {
     const templateVisitor = new TemplateDefinitionBuilder(
         this.outputCtx, this.constantPool, this.reflector, templateContext,
         this.bindingScope.nestedScope(), this.level + 1, this.ngContentSelectors, contextName,
-        templateName, this.pipes);
+        templateName, this.pipes, []);
     const templateFunctionExpr = templateVisitor.buildTemplateFunction(ast.children, ast.variables);
     this._postfix.push(templateFunctionExpr.toDeclStmt(templateName, null));
   }
@@ -643,9 +676,7 @@ class TemplateDefinitionBuilder implements TemplateAstVisitor, LocalResolver {
 
   private temp(): o.ReadVarExpr {
     if (!this._temporaryAllocated) {
-      this._prefix.push(o.variable(TEMPORARY_NAME, o.DYNAMIC_TYPE,  null)
+      this._prefix.push(new o.DeclareVarStmt(TEMPORARY_NAME, undefined, o.DYNAMIC_TYPE));
-                            .set(o.literal(undefined))
-                            .toDeclStmt(o.DYNAMIC_TYPE));
       this._temporaryAllocated = true;
     }
     return o.variable(TEMPORARY_NAME);
@@ -665,9 +696,31 @@ class TemplateDefinitionBuilder implements TemplateAstVisitor, LocalResolver {
   }
 }
 
+function getQueryPredicate(query: CompileQueryMetadata, outputCtx: OutputContext): o.Expression {
+  let predicate: o.Expression;
+  if (query.selectors.length > 1 || (query.selectors.length == 1 && query.selectors[0].value)) {
+    const selectors = query.selectors.map(value => value.value as string);
+    selectors.some(value => !value) && error('Found a type among the string selectors expected');
+    predicate = outputCtx.constantPool.getConstLiteral(
+        o.literalArr(selectors.map(value => o.literal(value))));
+  } else if (query.selectors.length == 1) {
+    const first = query.selectors[0];
+    if (first.identifier) {
+      predicate = outputCtx.importExpr(first.identifier.reference);
+    } else {
+      error('Unexpected query form');
+      predicate = o.literal(null);
+    }
+  } else {
+    error('Unexpected query form');
+    predicate = o.literal(null);
+  }
+  return predicate;
+}
+
 export function createFactory(
-    type: CompileTypeMetadata, outputCtx: OutputContext,
+    type: CompileTypeMetadata, outputCtx: OutputContext, reflector: CompileReflector,
-    reflector: CompileReflector): o.FunctionExpr {
+    queries: CompileQueryMetadata[]): o.Expression {
   let args: o.Expression[] = [];
 
   const elementRef = reflector.resolveExternalReference(Identifiers.ElementRef);
@@ -700,10 +753,74 @@ export function createFactory(
     }
   }
 
+  const queryDefinitions: o.Expression[] = [];
+  for (let query of queries) {
+    const predicate = getQueryPredicate(query, outputCtx);
+
+    // e.g. r3.Q(null, SomeDirective, false) or r3.Q(null, ['div'], false)
+    const parameters = [
+      /* memoryIndex */ o.literal(null, o.INFERRED_TYPE),
+      /* predicate */ predicate,
+      /* descend */ o.literal(query.descendants)
+    ];
+
+    if (query.read) {
+      parameters.push(outputCtx.importExpr(query.read.identifier !.reference));
+    }
+
+    queryDefinitions.push(o.importExpr(R3.query).callFn(parameters));
+  }
+
+  const createInstance = new o.InstantiateExpr(outputCtx.importExpr(type.reference), args);
+  const result = queryDefinitions.length > 0 ? o.literalArr([createInstance, ...queryDefinitions]) :
+                                               createInstance;
+
   return o.fn(
-      [],
+      [], [new o.ReturnStatement(result)], o.INFERRED_TYPE, null,
-      [new o.ReturnStatement(new o.InstantiateExpr(outputCtx.importExpr(type.reference), args))],
+      type.reference.name ? `${type.reference.name}_Factory` : null);
-      o.INFERRED_TYPE, null, type.reference.name ? `${type.reference.name}_Factory` : null);
+}
+
+// Return a host binding function or null if one is not necessary.
+export function createHostBindingsFunction(
+    type: CompileTypeMetadata, outputCtx: OutputContext,
+    queries: CompileQueryMetadata[]): o.Expression|null {
+  const statements: o.Statement[] = [];
+
+  const temporary = function() {
+    let declared = false;
+    return () => {
+      if (!declared) {
+        statements.push(new o.DeclareVarStmt(TEMPORARY_NAME, undefined, o.DYNAMIC_TYPE));
+        declared = true;
+      }
+      return o.variable(TEMPORARY_NAME);
+    };
+  }();
+
+  for (let index = 0; index < queries.length; index++) {
+    const query = queries[index];
+
+    // e.g. r3.qR(tmp = r3.ld(dirIndex)[1]) && (r3.ld(dirIndex)[0].someDir = tmp);
+    const getDirectiveMemory = o.importExpr(R3.load).callFn([o.variable('dirIndex')]);
+    // The query list is at the query index + 1 because the directive itself is in slot 0.
+    const getQueryList = getDirectiveMemory.key(o.literal(index + 1));
+    const assignToTemporary = temporary().set(getQueryList);
+    const callQueryRefresh = o.importExpr(R3.queryRefresh).callFn([assignToTemporary]);
+    const updateDirective = getDirectiveMemory.key(o.literal(0, o.INFERRED_TYPE))
+                                .prop(query.propertyName)
+                                .set(query.first ? temporary().key(o.literal(0)) : temporary());
+    const andExpression = callQueryRefresh.and(updateDirective);
+    statements.push(andExpression.toStmt());
+  }
+
+  if (statements.length > 0) {
+    return o.fn(
+        [new o.FnParam('dirIndex', o.NUMBER_TYPE), new o.FnParam('elIndex', o.NUMBER_TYPE)],
+        statements, o.INFERRED_TYPE, null,
+        type.reference.name ? `${type.reference.name}_HostBindings` : null);
+  }
+
+  return null;
 }
 
 class ValueConverter extends AstMemoryEfficientTransformer {

packages/compiler/test/render3/r3_compiler_compliance_spec.ts

@@ -551,6 +551,133 @@ describe('compiler compliance', () => {
           result.source, ComplexComponentDefinition, 'Incorrect ComplexComponent definition');
     });
 
+    describe('queries', () => {
+      const directive = {
+        'some.directive.ts': `
+          import {Directive} from '@angular/core';
+
+          @Directive({
+            selector: '[someDir]',
+          })
+          export class SomeDirective { }
+        `
+      };
+
+      it('should support view queries', () => {
+        const files = {
+          app: {
+            ...directive,
+            'view_query.component.ts': `
+            import {Component, NgModule, ViewChild} from '@angular/core';
+            import {SomeDirective} from './some.directive';
+
+            @Component({
+              selector: 'view-query-component',
+              template: \`
+              <div someDir></div>
+              \`
+            })
+            export class ViewQueryComponent {
+              @ViewChild(SomeDirective) someDir: SomeDirective;
+            }
+
+            @NgModule({declarations: [SomeDirective, ViewQueryComponent]})
+            export class MyModule {}
+          `
+          }
+        };
+
+        const ViewQueryComponentDefinition = `
+          const $e0_attrs$ = ['someDir',''];
+          const $e1_dirs$ = [SomeDirective];
+          …
+          static ngComponentDef = $r3$.ɵdefineComponent({
+            type: ViewQueryComponent,
+            tag: 'view-query-component',
+            factory: function ViewQueryComponent_Factory() { return new ViewQueryComponent(); },
+            template: function ViewQueryComponent_Template(ctx: $ViewQueryComponent$, cm: $boolean$) {
+              var $tmp$: $any$;
+              if (cm) {
+                $r3$.ɵQ(0, SomeDirective, true);
+                $r3$.ɵE(1, 'div', $e0_attrs$, $e1_dirs$);
+                $r3$.ɵe();
+              }
+              ($r3$.ɵqR(($tmp$ = $r3$.ɵld(0))) && (ctx.someDir = $tmp$.first));
+              SomeDirective.ngDirectiveDef.h(2, 1);
+              $r3$.ɵr(2, 1);
+            }
+          });`;
+
+        const result = compile(files, angularFiles);
+        const source = result.source;
+
+        expectEmit(source, ViewQueryComponentDefinition, 'Invalid ViewQuery declaration');
+      });
+
+      it('should support content queries', () => {
+        const files = {
+          app: {
+            ...directive,
+            'spec.ts': `
+            import {Component, ContentChild, NgModule} from '@angular/core';
+            import {SomeDirective} from './some.directive';
+
+            @Component({
+              selector: 'content-query-component',
+              template: \`
+                <div><ng-content></ng-content></div>
+              \`
+            })
+            export class ContentQueryComponent {
+              @ContentChild(SomeDirective) someDir: SomeDirective;
+            }
+
+            @Component({
+              selector: 'my-app',
+              template: \`
+                <content-query-component>
+                  <div someDir></div>
+                </content-query-component>
+              \`
+            })
+            export class MyApp { }
+
+            @NgModule({declarations: [SomeDirective, ContentQueryComponent, MyApp]})
+            export class MyModule { }
+            `
+          }
+        };
+
+        const ContentQueryComponentDefinition = `
+          static ngComponentDef = $r3$.ɵdefineComponent({
+            type: ContentQueryComponent,
+            tag: 'content-query-component',
+            factory: function ContentQueryComponent_Factory() {
+              return [new ContentQueryComponent(), $r3$.ɵQ(null, SomeDirective, true)];
+            },
+            hostBindings: function ContentQueryComponent_HostBindings(
+                dirIndex: $number$, elIndex: $number$) {
+              var $tmp$: $any$;
+              ($r3$.ɵqR(($tmp$ = $r3$.ɵld(dirIndex)[1])) && ($r3$.ɵld(dirIndex)[0].someDir = $tmp$[0]));
+            },
+            template: function ContentQueryComponent_Template(
+                ctx: $ContentQueryComponent$, cm: $boolean$) {
+              if (cm) {
+                $r3$.ɵpD(0);
+                $r3$.ɵE(1, 'div');
+                $r3$.ɵP(2, 0);
+                $r3$.ɵe();
+              }
+            }
+          });`;
+
+        const result = compile(files, angularFiles);
+
+        const source = result.source;
+        expectEmit(source, ContentQueryComponentDefinition, 'Invalid ContentQuery declaration');
+      });
+    });
+
     describe('pipes', () => {
 
       const files = {