angular-docs-cn/modules/@angular/compiler/src/view_compiler/property_binder.ts

/**
 * @license
 * Copyright Google Inc. 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 {SecurityContext} from '@angular/core';

import {createCheckBindingField, createCheckBindingStmt} from '../compiler_util/binding_util';
import {ConvertPropertyBindingResult, convertPropertyBinding} from '../compiler_util/expression_converter';
import {createEnumExpression} from '../compiler_util/identifier_util';
import {triggerAnimation, writeToRenderer} from '../compiler_util/render_util';
import {DirectiveWrapperExpressions} from '../directive_wrapper_compiler';
import * as cdAst from '../expression_parser/ast';
import {isPresent} from '../facade/lang';
import {Identifiers, resolveIdentifier} from '../identifiers';
import * as o from '../output/output_ast';
import {EMPTY_STATE as EMPTY_ANIMATION_STATE, LifecycleHooks, isDefaultChangeDetectionStrategy} from '../private_import_core';
import {ElementSchemaRegistry} from '../schema/element_schema_registry';
import {BoundElementPropertyAst, BoundEventAst, BoundTextAst, DirectiveAst, PropertyBindingType} from '../template_parser/template_ast';
import {camelCaseToDashCase} from '../util';

import {CompileElement, CompileNode} from './compile_element';
import {CompileMethod} from './compile_method';
import {CompileView} from './compile_view';
import {DetectChangesVars, ViewProperties} from './constants';
import {getHandleEventMethodName} from './util';

export function bindRenderText(
    boundText: BoundTextAst, compileNode: CompileNode, view: CompileView): void {
  const valueField = createCheckBindingField(view);
  const evalResult = convertPropertyBinding(
      view, view, view.componentContext, boundText.value, valueField.bindingId);
  if (!evalResult) {
    return null;
  }

  view.detectChangesRenderPropertiesMethod.resetDebugInfo(compileNode.nodeIndex, boundText);
  view.detectChangesRenderPropertiesMethod.addStmts(createCheckBindingStmt(
      evalResult, valueField.expression, DetectChangesVars.throwOnChange,
      [o.THIS_EXPR.prop('renderer')
           .callMethod('setText', [compileNode.renderNode, evalResult.currValExpr])
           .toStmt()]));
}

export function bindRenderInputs(
    boundProps: BoundElementPropertyAst[], hasEvents: boolean, compileElement: CompileElement) {
  var view = compileElement.view;
  var renderNode = compileElement.renderNode;
  boundProps.forEach((boundProp) => {
    const bindingField = createCheckBindingField(view);
    view.detectChangesRenderPropertiesMethod.resetDebugInfo(compileElement.nodeIndex, boundProp);
    const evalResult = convertPropertyBinding(
        view, view, compileElement.view.componentContext, boundProp.value, bindingField.bindingId);
    if (!evalResult) {
      return;
    }
    var checkBindingStmts: o.Statement[] = [];
    var compileMethod = view.detectChangesRenderPropertiesMethod;
    switch (boundProp.type) {
      case PropertyBindingType.Property:
      case PropertyBindingType.Attribute:
      case PropertyBindingType.Class:
      case PropertyBindingType.Style:
        checkBindingStmts.push(...writeToRenderer(
            o.THIS_EXPR, boundProp, renderNode, evalResult.currValExpr,
            view.genConfig.logBindingUpdate));
        break;
      case PropertyBindingType.Animation:
        compileMethod = view.animationBindingsMethod;
        const {updateStmts, detachStmts} = triggerAnimation(
            o.THIS_EXPR, o.THIS_EXPR, boundProp,
            (hasEvents ? o.THIS_EXPR.prop(getHandleEventMethodName(compileElement.nodeIndex)) :
                         o.importExpr(resolveIdentifier(Identifiers.noop)))
                .callMethod(o.BuiltinMethod.Bind, [o.THIS_EXPR]),
            compileElement.renderNode, evalResult.currValExpr, bindingField.expression);
        checkBindingStmts.push(...updateStmts);
        view.detachMethod.addStmts(detachStmts);
        break;
    }
    compileMethod.addStmts(createCheckBindingStmt(
        evalResult, bindingField.expression, DetectChangesVars.throwOnChange, checkBindingStmts));
  });
}

export function bindDirectiveHostProps(
    directiveAst: DirectiveAst, directiveWrapperInstance: o.Expression,
    compileElement: CompileElement, elementName: string,
    schemaRegistry: ElementSchemaRegistry): void {
  // We need to provide the SecurityContext for properties that could need sanitization.
  const runtimeSecurityCtxExprs =
      directiveAst.hostProperties.filter(boundProp => boundProp.needsRuntimeSecurityContext)
          .map((boundProp) => {
            let ctx: SecurityContext;
            switch (boundProp.type) {
              case PropertyBindingType.Property:
                ctx = schemaRegistry.securityContext(elementName, boundProp.name, false);
                break;
              case PropertyBindingType.Attribute:
                ctx = schemaRegistry.securityContext(elementName, boundProp.name, true);
                break;
              default:
                throw new Error(
                    `Illegal state: Only property / attribute bindings can have an unknown security context! Binding ${boundProp.name}`);
            }
            return createEnumExpression(Identifiers.SecurityContext, ctx);
          });
  compileElement.view.detectChangesRenderPropertiesMethod.addStmts(
      DirectiveWrapperExpressions.checkHost(
          directiveAst.hostProperties, directiveWrapperInstance, o.THIS_EXPR,
          compileElement.component ? compileElement.appElement.prop('componentView') : o.THIS_EXPR,
          compileElement.renderNode, DetectChangesVars.throwOnChange, runtimeSecurityCtxExprs));
}

export function bindDirectiveInputs(
    directiveAst: DirectiveAst, directiveWrapperInstance: o.Expression, dirIndex: number,
    compileElement: CompileElement) {
  var view = compileElement.view;
  var detectChangesInInputsMethod = view.detectChangesInInputsMethod;
  detectChangesInInputsMethod.resetDebugInfo(compileElement.nodeIndex, compileElement.sourceAst);

  directiveAst.inputs.forEach((input, inputIdx) => {
    // Note: We can't use `fields.length` here, as we are not adding a field!
    const bindingId = `${compileElement.nodeIndex}_${dirIndex}_${inputIdx}`;
    detectChangesInInputsMethod.resetDebugInfo(compileElement.nodeIndex, input);
    const evalResult =
        convertPropertyBinding(view, view, view.componentContext, input.value, bindingId);
    if (!evalResult) {
      return;
    }
    detectChangesInInputsMethod.addStmts(evalResult.stmts);
    detectChangesInInputsMethod.addStmt(
        directiveWrapperInstance
            .callMethod(
                `check_${input.directiveName}`,
                [
                  evalResult.currValExpr, DetectChangesVars.throwOnChange,
                  evalResult.forceUpdate || o.literal(false)
                ])
            .toStmt());
  });
  var isOnPushComp = directiveAst.directive.isComponent &&
      !isDefaultChangeDetectionStrategy(directiveAst.directive.changeDetection);
  let directiveDetectChangesExpr = DirectiveWrapperExpressions.ngDoCheck(
      directiveWrapperInstance, o.THIS_EXPR, compileElement.renderNode,
      DetectChangesVars.throwOnChange);
  const directiveDetectChangesStmt = isOnPushComp ?
      new o.IfStmt(directiveDetectChangesExpr, [compileElement.appElement.prop('componentView')
                                                    .callMethod('markAsCheckOnce', [])
                                                    .toStmt()]) :
      directiveDetectChangesExpr.toStmt();
  detectChangesInInputsMethod.addStmt(directiveDetectChangesStmt);
}