Interpolation not working in angular2

Question

import {Component} from 'angular2/core';
import {Observable} from 'rxjs/Observable';
import {Http} from 'angular2/http';
import {SpsheetService} from './spsheet.service';
import 'rxjs/Rx';


@Component({
 selector: 'my-spsheet',
 template: `
             <button id="fetch" (click)="reloadData()">Reload Data</button>
            <table class="table">
            <thead>
                <tr>
                    <th *ngFor="#head of heads">
                        {{head | async}}
                    </th>
                </tr>
            </thead>
            <tbody>
                <tr *ngFor="#dat of data">
                    <td *ngFor="#head of heads" contenteditable="true">
                        {{dat.head | async}}
                    </td>
                </tr>
            </tbody>
        </table>
        `,
providers: [SpsheetService]
 })

export class SpsheetComponent {
    data:any[];
    heads:string[];
    otherdata:string[];
    constructor(private _http:Http,private _spservice:SpsheetService){}

    reloadData(){
        this._spservice.fetchData()
            .subscribe(function(data) 
            {
                var me =this;
                me.data =[];
                me.data = data;
                me.heads = Object.keys(data[0]);
                var len = me.heads.length;
                console.log(me.heads);

            },
            err => console.log(err),
            () => console.log('Completed'));
    }


 }

I am loading data from a JSON file and structuring it into an HTML table. I am able to fetch the data and also structure it but the problem is it wont reflect as an HTML table, ie interpolation isn't working. Although the variables are carrying there respective values.

Answer 1

use arrow functions instead to keep the context of 'this' intact.

reloadData() {
            this._spservice.fetchData()
                .subscribe((data) => {
                    this.data = [];
                    this.data = data;
                    this.heads = Object.keys(data[0]);
                    var len = this.heads.length;
                    console.log(this.heads);
                },
                err => console.log(err),
                () => console.log('Completed'));
        }

Answer 2

I have worked around it, it was actually an issue with 'this' instance of the subscriber.

The actual correct code is:

import {Component} from 'angular2/core';
import {Observable} from 'rxjs/Observable';
import {Http} from 'angular2/http';
import {SpsheetService} from './spsheet.service';
import 'rxjs/Rx';


@Component({
 selector: 'my-spsheet',
 template: `
             <button id="fetch" (click)="reloadData()">Reload Data</button>
            <table class="table">
            <thead>
                <tr>
                    <th *ngFor="#head of heads">
                        {{head}}
                    </th>
                </tr>
            </thead>
            <tbody>
                <tr *ngFor="#dat of data">
                    <td *ngFor="#head of heads" contenteditable="true">
                        {{dat[head]}}
                    </td>
                </tr>
            </tbody>
        </table>
        `,
providers: [SpsheetService]
 })

export class SpsheetComponent {
    data:any[];
    heads:string[];
    otherdata:string[];
    constructor(private _http:Http,private _spservice:SpsheetService){}

    reloadData(){
        var me =this;
        me._spservice.fetchData()
            .subscribe(function(data) 
            {
                me.data =[];
                me.data = data;
                me.heads = Object.keys(data[0]);
                var len = me.heads.length;
                console.log(me.heads);

            },
            err => console.log(err),
            () => console.log('Completed'));
    }


 }

Answer 3

You have got an Extra BackTick that is causing the entire code to be a string. Just remove that. Copy paste this code below:-

import {Component} from 'angular2/core';
import {Observable} from 'rxjs/Observable';
import {Http} from 'angular2/http';
import {SpsheetService} from './spsheet.service';
import 'rxjs/Rx';


@Component({
 selector: 'my-spsheet',
 template: `
             <button id="fetch" (click)="reloadData()">Reload Data</button>
            <table class="table">
            <thead>
                <tr>
                    <th *ngFor="#head of heads">
                        {{head | async}}
                    </th>
                </tr>
            </thead>
            <tbody>
                <tr *ngFor="#dat of data">
                    <td *ngFor="#head of heads" contenteditable="true">
                        {{dat.head | async}}
                    </td>
                </tr>
            </tbody>
        </table>
        `,
],
providers: [SpsheetService]
 })

export class SpsheetComponent {
    data:any[];
    heads:string[];
    otherdata:string[];
    constructor(private _http:Http,private _spservice:SpsheetService){}

    reloadData(){
        this._spservice.fetchData()
            .subscribe(function(data) 
            {
                var me =this;
                me.data =[];
                me.data = data;
                me.heads = Object.keys(data[0]);
                var len = me.heads.length;
                console.log(me.heads);

            },
            err => console.log(err),
            () => console.log('Completed'));
    }


 }