Angular 2+ - Parse JSON as number - json

I want to place a marker on Google Maps using Angular Google Maps my coordinates are from JSON file which when parses in Angular it's become a string.
Angular Google Maps does not support string for coordinates number. So It needs to be number.
marker.json
[
{
"id":"1",
"lat":"13.751814",
"lon":"100.501060"
},
{
"id":"2",
"lat":"13.738445",
"lon":"100.516805"
},
{
"id":"3",
"lat":"13.730209",
"lon":"100.779991"
}
]
maps.componenet.ts
import { Component, OnInit } from '#angular/core';
import {Http, Response} from '#angular/http';
#Component({
selector: 'app-maps',
templateUrl: './maps.component.html',
styleUrls: ['./maps.component.css']
})
export class MapsComponent implements OnInit {
private data;
constructor(private http:Http){
}
ngOnInit(){
this.getData();
}
getData(){
this.http.get('/localhost/marker.json')
.subscribe(res => this.data = res.json());
}
}
maps.component.html
<agm-map [latitude]="13.359665" [longitude]="101.035913" [zoom]="6">
<ng-container *ngFor="let list of data">
<agm-marker [latitude]="list.lat" [longitude]="list.lon"></agm-marker>
</ng-container>
</agm-map>
I have tried using parseFloat like this (Yes it's not working)
<agm-marker [latitude]="parseFloat(list.lat)" [longitude]="parseFloat(list.lon)"></agm-marker>
I'm thinking of using parseInt inside maps.component.ts file but I'm not sure where to put this.
May someone helps me or guide me how to solve this.And please let me know that am I providing sufficient information or not.
Thanks!

A cleaner and more performant way is to process data once and provide it in view in a way that doesn't need any other preparations:
getData(){
this.http.get('/localhost/marker.json')
.map(res => res.json())
.map((data: any[]) => data.map(
({ lon, lat, ...props }) => ({ lon: +lon, lat: +lat, ...props })
))
.subscribe(data => {
this.data = data;
});
}
If marker.json doesn't have other props except listed ones, ...props can be replaced with known id property.

Global functions like parseFloat are not allowed in Angular templates (see the Angular documentation).
You can convert strings to numbers with the + operator:
<agm-marker [latitude]="+list.lat" [longitude]="+list.lon"></agm-marker>
or define a method in your component:
convertCoordinate(str: string): number {
return parseFloat(str);
}
and call it in the template:
<agm-marker [latitude]="convertCoordinate(list.lat)" [longitude]="convertCoordinate(list.lon)"></agm-marker>

+lat won't work in Angular template, it's invalid syntax and will throw an error, as well as parseFloat or parseInt, in here you can parse the JSON in the request like #estus pointed out OR you can multiply the string by 1:
<agm-marker [latitude]="list.lat * 1" [longitude]="list.lon * 1"></agm-marker>
This will transform the string into a number but beware that if it's NOT a number there will be error and you won't be able to catch it.

Related

How to fetch and use data from a JSON file in Angular7

I am trying to fetch data from a JSON file and display that data in the form
JSON FILE Link:
https://raw.githubusercontent.com/datameet/railways/master/trains.json
I am trying with the below code. But it returns following error in fetchdata.component.ts file:
Property 'json' does not exist on type 'Object'.
fetchdata.component.ts
import { Component, OnInit } from '#angular/core';
import { HttpClient } from '#angular/common/http';
#Component({
selector: 'app-fetchdata',
templateUrl: './fetchdata.component.html',
styleUrls: ['./fetchdata.component.css']
})
export class FetchdataComponent implements OnInit {
private _trainUrl = "https://raw.githubusercontent.com/datameet/railways/master/trains.json
";
items : any;
constructor(private http:HttpClient) {
this.http.get( this._trainUrl)
.subscribe(res => this.items = res.json());
console.log(this.items);
}
ngOnInit() {
}
}
fetchdata.component.html
<select>
<option *ngFor="let item of items" [value]="item.properties.from_station_name">{{item.properties.from_station_name}}</option>
</select>
Please help.
The response probably isn't what you think. I suggest you console.log() the response of your query to see what it actually looks like:
items : any;
constructor(private http:HttpClient) {
this.http.get( this._trainUrl)
.subscribe(res => {
this.items = res.features;
console.log("Response", res);
console.log(res.features)
});
}
You'll see that you actually get something like this in your console:
{type: "FeatureCollection", features: Array(5208)}
features: (5208) [{…}, …]
type: "FeatureCollection"
__proto__: Object
So you can assign your items to the features key as that's what you really need:
constructor(private http:HttpClient) {
this.http.get( this._trainUrl)
.subscribe(res => {
this.items = res["features"];
});
}
Then your select options should show up.
Just letting you know, this isn't the perfect way to do it but it works fine for a small example like this.
I suggest you look into creating a service for any request in the future (doing it in the constructor isn't the best way) and have a look at the RxJS library
There is a difference between Angular's Http and HttpClient module and they are also exported differently.
Http -> is the core module which requires the user to call res.json(). This was common prior to Angular version 4.0.
HttpClient -> is new module since version 4.0. It defaults the communication to json and hence you don't need to call res.json() explicitly.
In short, changing from res.json() to just res will fix the issue
for you.
i.e this.items = res; should be fine.
Also, as a good practice use the ngOnInit lifecycle method instead of the constructor to make any Http calls.
Why do you do this.items = res.json()? Why not just this.items = res? res should already hold the JSON object returned from the GET request. If it is indeed a string try this.items = JSON.parse(res).
Can you try :
private _trainUrl = "https://raw.githubusercontent.com/datameet/railways/master/trains.json";
items : any;
constructor(private http:HttpClient) {}
ngOnInit() {
this.http.get( this._trainUrl).subscribe(res => {
this.items = res;
console.log(this.items);
});
}
You don't need to call .json() function in case you doing plain this.http.get. Angular does that for you. Simply do this.items = res. That will do the trick.
UPD: your JSON object is not an array itself. You as well need to update your template in the following way:
<select>
<option *ngFor="let item of items.features" [value]="item.properties.from_station_name">{{item.properties.from_station_name}}</option>
</select>

Loading data from a json file with an Interface

I'm writing a little ionic app for learning purposes and I would like to load data from a json file and assign it to an Interface that describes the data. But I'm struggling with getting it the right way:
import { Component } from "#angular/core";
import { HttpClient} from "#angular/common/http";
export interface PhonebookEntry {
name: string,
telephone: string,
description: string
}
#Component({
selector: 'page-phonebook',
templateUrl: 'phonebook.html'
})
export class PhonebookPage {
entries: Array<PhonebookEntry>;
constructor(public http: HttpClient) {
this.load_entries('assets/json/phonebook.json');
};
load_entries(filePath: string) {
return this.http.get(filePath)
.subscribe(
data => this.entries = data
);
};
}
I think only the line data => this.entries = data is wrong (also the IDE is telling me that), but I don't know to do this right and can't find documentation describing the correct way. If there actually is some I would be glad to know where I can find ressources about this.
subscribe return the response as an object, not as an array. So entries type should be changed.
entries: PhonebookEntry;
In the subscribe, need to assign a type for response data.
load_entries(filePath: string) {
return this.http.get(filePath)
.subscribe(
(data: PhonebookEntry) => this.entries = data // or use any type
);
};
Demo

Getting [Object Object] in angular2 application

I have developed angular2 application using ngrx/effects for making http calls. I have used GIT as reference application. Once the response come from http, i am not able to display it on screen. Its showing [object Object]. Here is my code.
HTML page linked to component.html
<div class="container">
<div class="left-container cf">
<mat-tab-group>
<mat-tab label="Configuration">{{jsons}}</mat-tab>
<mat-tab label="Captured Output">
</mat-tab>
</mat-tab-group>
</div>
</div>
Component.ts
export class ExperimentDetailsComponent implements OnInit {
jsons: Observable<any>;
isLoading: Observable<any>;
constructor(
private store: Store<fromStore.State>
) {
this.isLoading = store.select(fromStore.getIsLoading);
this.jsons = store.select(fromStore.getJson);
console.log(this.jsons)
}
ngOnInit() {
this.store.dispatch(new jsonAction.GetJson());
// this.jsons = this.store.select(fromStore.getJson);
}
}
Effects.ts
export class GetJsonEffects {
#Effect() json$ = this.actions$.ofType(Act.GET_JSON)
.map(toPayload)
.withLatestFrom(this.store$)
.mergeMap(([ payload, store ]) => {
return this.http$
.get(`http://localhost:4000/data/`)
.map(data => {
return new Act.GetJsonSuccess({ data: data })
})
.catch((error) => {
return Observable.of(
new Act.GetJsonFailed({ error: error })
);
})
});
constructor(
private actions$: Actions,
private http$: HttpClient,
private store$: Store<fromStore.State>
) {}
}
As you see, the result of store.select() is an observable. You cannot data bind to it directly.
You can either:
Use the async pipe to make the UI subscribe to the observable for you and extract the data, like:
<mat-tab label="Configuration">{{jsons | async}}</mat-tab>
Or subscribe yourself to the observable.
export class ExperimentDetailsComponent implements OnInit {
jsonSubscription = store.select(fromStore.getJson)
.subscribe(jsons => this.jsons = jsons);
ngOnDestroy() {
this.jsonSubscription.unsubscribe();
}
jsons: any;
// ...
}
That's one thing:
If you are using Http service (from #angular/http module):
The other thing is that you are returning the Response object not the JSON extracted from it. The map() in your effect needs to call data.json(). Like:
return this.http$
.get(`http://localhost:4000/data/`)
.map(data => {
return new Act.GetJsonSuccess({ data: data.json() })
})
Or, as I like, add another map() to make things clear:
return this.http$
.get(`http://localhost:4000/data/`)
// You could also create an interface and do:
// `response.json() as MyInterfaceName`
// to get intellisense, error checking, etc
.map(response => response.json())
.map(data => {
return new Act.GetJsonSuccess({ data: data })
})
If you are using HttpClient service (from #angular/common/http module):
(Available in Angular v4.3+)
In this case you don't need to call .json() yourself, it does it for you, so you don't need that first .map() I suggested.
You can also tell TypeScript about the type you expect the JSON to match by calling the get() like this:
return this.http$
.get<MyInterfaceName>(`http://localhost:4000/data/`)
.map(data => {
return new Act.GetJsonSuccess({ data: data.json() })
})
The get<MyInterfaceName>() bit will make Angular tell TypeScript that the JSON object matches the MyInterfaceName, so you'll get intellisense and error checking based on this (at compile time only, none of this affects runtime in anyway).
HttpClient Documentation

http observable<any> - Angular 4

I need to display the data on html that I get from web service. I am able to see the data in a format that I want, but I can't display properly on html. I think -any- in http.get is the problem. I can read data in console without -any- but it works fine with . When it works with it, it still does not print in html properly. Can anyone provide advice on this?
html
<div>{{this.res}}</div>
app.component.ts
import { Component, OnInit } from '#angular/core';
//import { IMovie } from './movie';
import { AppService } from './app.service';
#Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
res: any[] ;
errorMessage: string;
constructor(private _appService: AppService) { }
ngOnInit(): void { this.getData(); }
getData(): void {
this._appService.getData()
.subscribe(
(res: any []) => this.res = res,
(error: any) => this.errorMessage = <any>error);
}
}
app.service.ts :
Injectable()
export class AppService {
private urlNorth = '';
constructor(private http: HttpClient) { }
getData(): Observable<any> {
const headers = new HttpHeaders();
headers.set('Content-Type', 'text/sml');
headers.set('Accept', 'text/xml');
headers.set('Content-Type', 'text/xml');
return this.http.get<any>(this.urlNorth,{responseType:'text', headers: headers})
.do(data => {
// console.log(data)
var dataParsed = data.replace('<string xmlns="service">', '').replace('</string>', '').replace(/</g, '<').replace(/>/g, '>');
// console.log(dataParsed);
parseString(dataParsed, (err, res) => {
if (err) {
return console.dir('invalid XML');
}
else {
console.log(res);
console.log(res.NewDataSet.Table[0].DataPointName[0]);
}
})
})
.catch(this.handleError);
}
**data in console w/o any **
{{this.res}} in html
I'm pretty sure you don't have to put any at this line in app.service.ts
return this.http.get<any>(this.urlNorth,{responseType:'text', headers: headers})
because get method expects 0 type arguments.
Type any is not the problem. It's just TypeScript annotation to organise your code. The problem is you are refering to the res in inline template as this.res, but you should just res. However it won't work as you think. Looking at your data structure You will have to iterate throught this data due to Table is an array. Additionaly I Highly suggest to always represnt your data as class
export class Apps {
public Table: Array<any>; //here should be another type instead of "any"
/* rest of data if any */
}
Back to your question you should have in your html file <div>{{res}}</div> but that's just print your object as string if I good remember. So to properly access your data you should iterate through table using *ngFor
<div *ngFor="let el of res.NewDataSet.Table">
<span>{{el.BackColor}}</span>
<!-- all other data -->
</div>
It looks as though the data is coming back. I'll answer your initial question first (since you added a few issues in comments):
My guess is when you get data back, it's not showing because it's HTML, and angular doesn't like injecting html.
Add this to your TS:
import { DomSanitizer, SafeHtml } from '#angular/platform-browser';
res[]: safeHTML;
And change your html to this:
<div [innerHTML]="res"></div>
As mentioned in a previous answer, this is a solution for a single return of res, not an array of different htmls. If it's an array, you'll have to handle it accordingly. for instance:
<ng-container *ngFor="let r of res">
<div [innerHTML]="r">
</ng-container>

How to iterate API data using ngFor in Angular 2

I am new in Angular 2 and I want to display all the API data in tabular form.
Here is my working code:
http://plnkr.co/edit/CB3oGppm4fvoEExfDSRc?p=preview
But when I am using this code in my files, I am having an error:
Type 'Response' is not assignable to type 'any[]'
test.component.html:
<h1>{{getData[0]?.name}}</h1>
<h1>{{getData[0]?.time}}</h1>
<div *ngFor="let item of getData">
<span>{{item?.name}}</span>
</div>
app.component.ts
import { Component } from '#angular/core';
import { ConfigurationService } from './ConfigurationService';
#Component({
selector: 'app-root',
templateUrl: './app.component.html'
})
export class AppComponent {
getData = [];
constructor(private _ConfigurationService: ConfigurationService)
{
console.log("Reading _ConfigurationService ");
//console.log(_ConfigurationService.getConfiguration());
this._ConfigurationService.getConfiguration()
.subscribe(
(data)=> {
this.getData = data;
console.log(this.getData);
},
(error) => console.log("error : " + error)
);
}
}
This code is working in Plunkr but having error when I try it in my project. Please help to iterate the API values in my project. Thank you.
That's because you haven't assigned type to your getData variable. If you change getData = []; to getData: any = [];, your code should work. Other solution is to change compiler options in your tsconfig.json file:
"compilerOptions": {
"noImplicitAny": false
}
If you set noImplicitAny to false, you don't have to assign type to variables, if you don't implicitly set variable's type, it will be set to any automatically.
The signature of your service method getConfiguration is
(): Observable<Response>
But the return type is not correct, it should be the type that the Observable will materialize. Example:
(): Observable<any[]>
You can make any a specific type.