在JSON文档中使用JavaScript读取多行字符串

这个问题已经在这里得到答案了:

JSON中允许使用多行字符串吗？

我有一个JSON文档，其中一些数据是多行字符串

我尝试了以下选项，但似乎都不起作用

例如

[
  {
    "someString" : "A rather long string of English text, an error message \
               actually that just keeps going and going -- an error \
               message to make the Energizer bunny blush (right through \
               those Schwarzenegger shades)! Where was I? Oh yes, \
               you've got an error and all the extraneous whitespace is \
               just gravy.  Have a nice day."
  }
]

或

[
  {
    "someString" : `A rather long string of English text, an error message` +
               `actually that just keeps going and going -- an error` +
               `message to make the Energizer bunny blush (right through` +
               `those Schwarzenegger shades)! Where was I? Oh yes,` +
               `you've got an error and all the extraneous whitespace is` +
               `just gravy.  Have a nice day.`
  }
]

或

[
  {
    "someString" : 'A rather long string of English text, an error message' +
               'actually that just keeps going and going -- an error' +
               'message to make the Energizer bunny blush (right through' +
               'those Schwarzenegger shades)! Where was I? Oh yes,' +
               'you've got an error and all the extraneous whitespace is' +
               'just gravy.  Have a nice day.'
  }
]

或这个组合与评论中建议的\\n，但这也没有起作用。

[
  {
"shortStory": "A rather long string of English text, an error message\n
           actually that just keeps going and going -- an error \n
           message to make the Energizer bunny blush (right through\n
           those Schwarzenegger shades)! Where was I? Oh yes,\n
           you've got an error and all the extraneous whitespace is\n
           just gravy.  Have a nice day."
  }
]

还有各种组合。只要有换行，代码就不起作用。

以下是读取JSON文件的代码（Angular 2/Javascript）

   import {
        Injectable
    } from '@angular/core';
    import {
        Http,
        Headers,
        RequestOptions,
        Response
    } from '@angular/http';
    import {
        Observable,
        Subject
    } from 'rxjs/Rx';
    import 'rxjs/Rx'; //get everything from Rx
    import 'rxjs/add/operator/toPromise';
    import {
        IArticle
    } from './article';
    @Injectable()
    export class ArticleService {
        private jsonFileURL: string = "./assets/data/article-data.json";
        constructor(private http: Http) {}
        //
        getArticles(): Observable < IArticle[] > {
            return this.http.get(this.jsonFileURL).map((response: Response) => {
                return <IArticle[] > response.json()
            }).catch(this.handleError);
        }
        //
        private handleError(errorResponse: Response) {
            //console.log(errorResponse.statusText);
            return Observable.throw(errorResponse.json().error || "Server error");
        }
    }