我正在尝试从API获取用户列表,但是我收到以下错误:
/project/svn/log/*.log { # path changed
...
create 644 svn svn # corrected group and made world-readable
...
我有一个调用homeService.getUsers()的登录组件,该组件使用HttpClient检索用户,但http请求永远不会到达服务器。
login.component.ts:
sudo mkdir /project/svn
sudo chmod 755 /project/svn
sudo mkdir /project/svn/repos /project/svn/log
sudo chown -R svn:svn /project/svn
sudo semanage fcontext -add --type svnserve_content_t "/project/svn(/.*)?"
sudo restorecon -Rv /project/svn
Home.service:
TypeError: Cannot read property 'toLowerCase' of undefined
at HttpXsrfInterceptor.intercept (http.js:2482)
at HttpInterceptorHandler.handle (http.js:1796)
at HttpInterceptingHandler.handle (http.js:2547)
at MergeMapSubscriber.eval [as project] (http.js:1466)
at MergeMapSubscriber._tryNext (mergeMap.js:128)
at MergeMapSubscriber._next (mergeMap.js:118)
at MergeMapSubscriber.Subscriber.next (Subscriber.js:92)
at ScalarObservable._subscribe (ScalarObservable.js:51)
at ScalarObservable.Observable._trySubscribe (Observable.js:172)
at ScalarObservable.Observable.subscribe (Observable.js:160)
和app.module:
import { Component, OnInit } from '@angular/core';
import { HomeService } from '../service/home.service';
import { User } from '../domain/user';
@Component({
selector: 'app-login',
templateUrl: './login.component.html',
styleUrls: ['./login.component.scss']
})
export class LoginComponent implements OnInit {
user: User = {
id: undefined,
userName: undefined,
password: undefined
};
users: User[];
constructor(
private homeService: HomeService
) { }
ngOnInit() {
this.getUsers();
}
getUsers(): void {
this.homeService.getUsers()
.subscribe(users => this.users = users);
}
}
我可以看到日志记录中显示的错误消息,所以它似乎是来自HttpClient的错误。但是在将Http请求发送到服务器之前,我无法弄清楚它为什么会失败。
答案 0 :(得分:7)
我遇到了同样的问题。问题是我已经声明了url,但是在做httpget时,我意识到url没有被分配任何值:
可能案例: 例: private yourUrl:string;
并在你的http电话中: 返回this.http.get(this.yourUrl,{headers:this.headers})
答案 1 :(得分:5)
似乎您错误地声明了一个变量,从而使它未定义: 试试这个
用于简洁编码
interface User = {
id: number;
userName: string;
password: string;
}
user: User;
也请改正此行
private usersUrl: 'http://localhost:8080/users';
收件人
private usersUrl = 'http://localhost:8080/users';
这可能是问题所在
答案 2 :(得分:1)
问题与您传递的URL有关:
private usersUrl: http://localhost:8080/users';
。
应为:
private usersUrl: string='http://localhost:8080/users';
答案 3 :(得分:0)
我遇到了同样的问题。 正如@Canlla所说,有必要将url变量的可见性从public更改为private。
奇怪,但有些东西正在改变它的价值!无论如何,它一定是 私有,因为我们不需要在模板上访问它。
就我而言,我需要添加NgIf / NgElse以避免在加载完成之前绑定数据:
<mat-list *ngIf="transactions | async; let transactions;else loading">
<div *ngFor="let transaction of transactions">
<h3 mat-subheader>{{ transaction.dueDate }}</h3>
<mat-list-item>
<img matListAvatar src="https://source.unsplash.com/random/100x100" alt="...">
<span matLine class="mat-body-2"> {{transaction.description}} </span>
<p matLine class="col col-6 left-align">
<span class="mat-body-1"> {{transaction.categoryName}} </span>
<br>
<span class="mat-caption"> {{transaction.accountName}} </span>
</p>
<p class="col col-6 right-align">
<span class="mat-subheading">{{ transaction.amount | currency:'BRL':'symbol' }}</span>
</p>
</mat-list-item>
</div>
</mat-list>
<ng-template #loading>Loading...</ng-template>
所以这里:
<mat-list *ngIf="transactions | async; let transactions;else loading">
如果async
已加载,我有{ngIf与mat-list
管道显示transactions
。
Next let user
语句如果为true,则创建一个Angular从Observable中分配值的本地模板变量。
否则else loading
告诉Angular是否满足条件以显示加载模板。
查看来自@coryrylan的这篇优秀帖子:https://coryrylan.com/blog/angular-async-data-binding-with-ng-if-and-ng-else
答案 4 :(得分:0)
我认为您的网址声明不正确 请尝试以下方式:
private usersUrl = 'http://localhost:8080/users';
答案 5 :(得分:0)
我也遇到了类似的错误,为了解决这个问题,我抬起头来发现自己错误地声明了URL。
声明应该像这样
private urlVariable = 'http://sampleurl.com';