2016-10-10 09:20:58 -07:00

81 lines
2.8 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 {isBlank, isPresent} from '../facade/lang';
import {EmitterVisitorContext, OutputEmitter} from './abstract_emitter';
import {AbstractJsEmitterVisitor} from './abstract_js_emitter';
import * as o from './output_ast';
import {ImportGenerator} from './path_util';
export class JavaScriptEmitter implements OutputEmitter {
constructor(private _importGenerator: ImportGenerator) {}
emitStatements(moduleUrl: string, stmts: o.Statement[], exportedVars: string[]): string {
var converter = new JsEmitterVisitor(moduleUrl);
var ctx = EmitterVisitorContext.createRoot(exportedVars);
converter.visitAllStatements(stmts, ctx);
var srcParts: string[] = [];
converter.importsWithPrefixes.forEach((prefix, importedModuleUrl) => {
// Note: can't write the real word for import as it screws up system.js auto detection...
srcParts.push(
`var ${prefix} = req` +
`uire('${this._importGenerator.getImportPath(moduleUrl, importedModuleUrl)}');`);
});
srcParts.push(ctx.toSource());
return srcParts.join('\n');
}
}
class JsEmitterVisitor extends AbstractJsEmitterVisitor {
importsWithPrefixes = new Map<string, string>();
constructor(private _moduleUrl: string) { super(); }
visitExternalExpr(ast: o.ExternalExpr, ctx: EmitterVisitorContext): any {
if (isBlank(ast.value.name)) {
throw new Error(`Internal error: unknown identifier ${ast.value}`);
}
if (isPresent(ast.value.moduleUrl) && ast.value.moduleUrl != this._moduleUrl) {
var prefix = this.importsWithPrefixes.get(ast.value.moduleUrl);
if (isBlank(prefix)) {
prefix = `import${this.importsWithPrefixes.size}`;
this.importsWithPrefixes.set(ast.value.moduleUrl, prefix);
}
ctx.print(`${prefix}.`);
}
ctx.print(ast.value.name);
return null;
}
visitDeclareVarStmt(stmt: o.DeclareVarStmt, ctx: EmitterVisitorContext): any {
super.visitDeclareVarStmt(stmt, ctx);
if (ctx.isExportedVar(stmt.name)) {
ctx.println(exportVar(stmt.name));
}
return null;
}
visitDeclareFunctionStmt(stmt: o.DeclareFunctionStmt, ctx: EmitterVisitorContext): any {
super.visitDeclareFunctionStmt(stmt, ctx);
if (ctx.isExportedVar(stmt.name)) {
ctx.println(exportVar(stmt.name));
}
return null;
}
visitDeclareClassStmt(stmt: o.ClassStmt, ctx: EmitterVisitorContext): any {
super.visitDeclareClassStmt(stmt, ctx);
if (ctx.isExportedVar(stmt.name)) {
ctx.println(exportVar(stmt.name));
}
return null;
}
}
function exportVar(varName: string): string {
return `Object.defineProperty(exports, '${varName}', { get: function() { return ${varName}; }});`;
}