angular-cn/packages/compiler/test/render3/view/util.ts

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/**
* @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 * as e from '../../../src/expression_parser/ast';
import * as a from '../../../src/render3/r3_ast';
export function findExpression(tmpl: a.Node[], expr: string): e.AST|null {
const res = tmpl.reduce((found, node) => {
if (found !== null) {
return found;
} else {
return findExpressionInNode(node, expr);
}
}, null as e.AST | null);
if (res instanceof e.ASTWithSource) {
return res.ast;
}
return res;
}
function findExpressionInNode(node: a.Node, expr: string): e.AST|null {
if (node instanceof a.Element || node instanceof a.Template) {
return findExpression(
[
...node.inputs,
...node.outputs,
...node.children,
],
expr);
} else if (node instanceof a.BoundAttribute || node instanceof a.BoundText) {
const ts = toStringExpression(node.value);
return toStringExpression(node.value) === expr ? node.value : null;
} else if (node instanceof a.BoundEvent) {
return toStringExpression(node.handler) === expr ? node.handler : null;
} else {
return null;
}
}
export function toStringExpression(expr: e.AST): string {
while (expr instanceof e.ASTWithSource) {
expr = expr.ast;
}
if (expr instanceof e.PropertyRead) {
if (expr.receiver instanceof e.ImplicitReceiver) {
return expr.name;
} else {
return `${toStringExpression(expr.receiver)}.${expr.name}`;
}
} else if (expr instanceof e.ImplicitReceiver) {
return '';
} else if (expr instanceof e.Interpolation) {
let str = '{{';
for (let i = 0; i < expr.expressions.length; i++) {
str += expr.strings[i] + toStringExpression(expr.expressions[i]);
}
str += expr.strings[expr.strings.length - 1] + '}}';
return str;
} else {
throw new Error(`Unsupported type: ${(expr as any).constructor.name}`);
}
}