在构建使用Firebase的角应用程序时如何处理所有可观测到的
在构建使用Firebase的角应用程序时如何处理所有可观测到的
提问于 2017-05-02 07:29:43
我已经建立了一些应用程序的角度和Firebase，我刚刚开始一个新的。我感兴趣的是其他人如何处理使用可观测数据获取数据的问题。在我的特定应用程序中，我需要使用一个可观察的程序从URL获取参数，检查用户是否经过身份验证，并从firebase获取两个不同的对象。我需要首先检查auth，然后从URL中获取参数，这样我就可以找到firebase对象的位置。在过去，我只是做了一窝可观察到的订阅，像这样。
ngOnInit() {
this.af.auth.subscribe(auth => {
if (auth) {
this.uid = auth.uid;
this.af.database.list('objectives', {
query: {
orderByChild: 'AuthorID',
equalTo: auth.uid
}
}).subscribe(objectives => {
console.log(objectives);
this.allObjectives = objectives;
})
} else {
this.router.navigate(['login'])
}
})
}现在，我必须添加参数和对firebase的另一个调用。我尝试过使用rxjs的combineLatest，但看起来我无法使用从一个可观察到的数据返回到另一个中的数据。我的问题是，有没有人在没有嵌套订阅的情况下解决了类似的问题？
下面是我的package.json文件
{
"name": "wdw-hunt",
"version": "0.0.0",
"license": "MIT",
"scripts": {
"ng": "ng",
"start": "ng serve",
"build": "ng build",
"test": "ng test",
"lint": "ng lint",
"e2e": "ng e2e"
},
"private": true,
"dependencies": {
"@angular/common": "^2.4.0",
"@angular/compiler": "^2.4.0",
"@angular/core": "^2.4.0",
"@angular/forms": "^2.4.0",
"@angular/http": "^2.4.0",
"@angular/platform-browser": "^2.4.0",
"@angular/platform-browser-dynamic": "^2.4.0",
"@angular/router": "^3.4.0",
"angular2-cookie": "^1.2.6",
"angularfire2": "^2.0.0-beta.8",
"bootstrap": "^3.3.7",
"core-js": "^2.4.1",
"firebase": "^3.9.0",
"hammer-timejs": "^1.1.0",
"hammerjs": "^2.0.8",
"ng2-bootstrap": "^1.4.2",
"ng2-simple-page-scroll": "^2.0.0",
"rxjs": "^5.1.0",
"zone.js": "^0.7.6"
},
"devDependencies": {
"@angular/cli": "1.0.0-rc.2",
"@angular/compiler-cli": "^2.4.0",
"@types/jasmine": "2.5.38",
"@types/node": "~6.0.60",
"codelyzer": "~2.0.0",
"firebase-cli": "^1.2.0",
"firebase-tools": "^3.5.0",
"jasmine-core": "~2.5.2",
"jasmine-spec-reporter": "~3.2.0",
"karma": "~1.4.1",
"karma-chrome-launcher": "~2.0.0",
"karma-cli": "~1.0.1",
"karma-coverage-istanbul-reporter": "^0.2.0",
"karma-jasmine": "~1.1.0",
"karma-jasmine-html-reporter": "^0.2.2",
"protractor": "~5.1.0",
"ts-node": "~2.0.0",
"tslint": "~4.5.0",
"typescript": "^2.3.2"
}
}下面是我的tsconfig
{
"compilerOptions": {
"sourceMap": true,
"declaration": false,
"moduleResolution": "node",
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"target": "es5",
"lib": [
"es2016",
"dom"
],
"outDir": "../out-tsc/app",
"module": "es2015",
"baseUrl": "",
"types": []
},
"exclude": [
"test.ts",
"**/*.spec.ts"
]
}回答 1
Stack Overflow用户
回答已采纳
发布于 2017-05-02 09:22:29
我就是这样做的
警卫：
import {Injectable} from '@angular/core';
import {ActivatedRouteSnapshot, CanActivate, Router, RouterStateSnapshot} from '@angular/router';
import {Observable} from 'rxjs/Observable';
import {AngularFire} from 'angularfire2';
import {isNullOrUndefined} from 'util';
@Injectable()
export class OverviewGuard implements CanActivate {
constructor(private af: AngularFire, private router: Router) {
}
canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
return this.af.auth.map(auth => {
if (isNullOrUndefined(auth)) {
this.router.navigate(['/login']);
return false;
} else {
return true;
}
});
}
}一些提供者：
import {Injectable} from '@angular/core';
import {AngularFire} from 'angularfire2';
import {Observable} from 'rxjs/Observable';
@Injectable()
export class JobProvider {
constructor(private af: AngularFire) {
}
public getSomething(): Observable<Something> {
return this.getUserDb()
.switchMap(path => this.af.database.object(`${path}/something`));
}
private getUserDb(): Observable<string> {
return this.af.auth
.map(auth => `/debug/users/${auth.uid}`);
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/43741790
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