angular-cn/modules/@angular/compiler/src/compiler_util/binding_util.ts

31 lines
1.1 KiB
TypeScript

/**
* @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 {ClassBuilder} from '../output/class_builder';
import * as o from '../output/output_ast';
export class CheckBindingField {
constructor(public expression: o.ReadPropExpr, public bindingId: string) {}
}
export function createCheckBindingField(builder: ClassBuilder): CheckBindingField {
const bindingId = `${builder.fields.length}`;
const fieldExpr = createBindFieldExpr(bindingId);
// private is fine here as no child view will reference the cached value...
builder.fields.push(new o.ClassField(fieldExpr.name, null, [o.StmtModifier.Private]));
builder.ctorStmts.push(o.THIS_EXPR.prop(fieldExpr.name).set(o.literal(undefined)).toStmt());
return new CheckBindingField(fieldExpr, bindingId);
}
function createBindFieldExpr(bindingId: string): o.ReadPropExpr {
return o.THIS_EXPR.prop(`_expr_${bindingId}`);
}
export function isFirstViewCheck(view: o.Expression): o.Expression {
return o.not(view.prop('numberOfChecks'));
}