I have this JSON: (this.url)
{
"user": [
{
"id": "1",
"name": "root",
"password": "root"
},
{
"id": "2",
"name": "clienttest",
"password": "123456"
}
]
}
and I have this service:
findUsers(id: number) : boolean {
return this.http.get(this.url)
.map((res: Response) => res.json());
.someOperator(to assert the id exist)...
}
I want to return true if the user was found.
Is there some operator like filter that can make this assert for me?
try to use Array.some() method:
findUsers(id: number) : boolean {
return this.http
.get(this.url)
.map((res: Response) => {
let result = res.json();
return result.user.some(user => parseInt(user.id) === id)
})
}
Inline simulation:
const data = {
"user": [
{
"id": "1",
"name": "root",
"password": "root"
},
{
"id": "2",
"name": "clienttest",
"password": "123456"
}
]
}
// this will simulate http get resolve being processed by res.json()
const httpGet = Rx.Observable.of(data);
const findUsers = id =>
httpGet.map(data => data.user.some(user => parseInt(user.id) === id))
;
findUsers(1).subscribe(result => console.log(result));
findUsers(3).subscribe(result => console.log(result));
<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/5.5.5/Rx.min.js"></script>
Related
typegraphql, typeorm, Mysql with master slave replication.
I have configured mysql with master and slave databases with separate instances and its working fine. I have encounter an error
while connecting via typeorm. Here's my ormconfig.json
{
"type": "mysql",
"logging": true,
"replication": {
"master":
{
"host": "192.168.0.250",
"port": 3306,
"username": "root",
"password": "test#123",
"database": "master",
"synchronize": true,
"extra": {
"connectionLimit": 5
}
}
,
"slaves": [
{
"host": "192.168.0.175",
"port": 3306,
"username": "root",
"password": "test#123",
"database": "master",
"synchronize": true,
"extra": {
"connectionLimit": 5
}
}
]
},
"entities": [
"src/entity/**/*.ts"
],
"migrations": [
"src/migration/**/*.ts"
],
"subscribers": [
"src/subscriber/**/*.ts"
],
"cli": {
"entitiesDir": "src/entity",
"migrationsDir": "src/migration",
"subscribersDir": "src/subscriber"
}
}
My index.ts file with database connection as
import { gqSchema } from './schema';
import "reflect-metadata";
import { createConnection } from "typeorm";
import { ApolloServer } from "apollo-server";
async function main() {
await createConnection().then(async(res) => {
console.log(res)
console.log("Database Connected")
const schema = await gqSchema()
const server = new ApolloServer({
schema,
context: ({ req }: any) => ({ req })
})
await server.listen(4000)
console.log("Server has started!")
}).catch(err => {
console.log("err", err)
})
}
main();
And my resolver.ts file
#Resolver()
export class UserResolver {
/**
* query
*/
#Authorized()
#Query(() => User)
async hello(
#Arg("firstName") firstName: string,
): Promise<User | undefined > {
const slaveQueryRunner = getConnection().createQueryRunner("slave");
try {
const connection = getConnection().getRepository(User);
const usersList = await connection.createQueryBuilder()
.from(User, "user")
.setQueryRunner(slaveQueryRunner)
.where("user.firstName = ", {firstName})
.getOne();
console.log(usersList)
} finally {
slaveQueryRunner.release();
}
}
}
Is there anyway to get a value in an object from a json array. I need to get a value from an object based on another value.
I have my code like:
export default class StandardComp extends Component {
constructor(props) {
super(props)
this.state = {
id: '',
email: 'abc#gmail.com',
dataSource: []
};
}
componentDidMount(){
fetch(someURL, {
method: 'GET',
headers: {
'Content-Type': 'application/json'
}
})
.then((response) => response.json())
.then((responseJson) => {
this.setState({dataSource: responseJson})
//dunno what to do here
})
.catch((error) => {
console.error(error);
})
}
}
My "responseJson" is something like this. Then providing the key value (abc#gmail.com), how could I get the string "abcdef"?
[
{
"id": "qwerty",
"email": "cat#gmail.com",
"name": "cat"
},
{
"id": "abcdef",
"email": "abc#gmail.com",
"name": "abc"
}
{
"id": "owowao",
"email": "dog#gmail.com",
"name": "dog"
},
]
Thank you in advance.
Find the element that matches email and return the id.
array::find
const data = [
{
"id": "qwerty",
"email": "cat#gmail.com",
"name": "cat"
},
{
"id": "abcdef",
"email": "abc#gmail.com",
"name": "abc"
},
{
"id": "owowao",
"email": "dog#gmail.com",
"name": "dog"
},
];
const findIdByEmail = (data, email) => {
const el = data.find(el => el.email === email); // Possibly returns `undefined`
return el && el.id; // so check result is truthy and extract `id`
}
console.log(findIdByEmail(data, 'cat#gmail.com'));
console.log(findIdByEmail(data, 'abc#gmail.com'));
console.log(findIdByEmail(data, 'gibberish'));
The code will depend on how you get the value abc#gmail.com.
You'll probably need to pass it in as an argument to componentDidMount via a prop? Or extract it to a separate function. It just depends.
Something like this is the most basic way I'd say.
const value = responseJson.filter(obj => obj.email === 'abc#gmail.com')[0].id
Here it is implemented in your class.
export default class StandardComp extends Component {
...
componentDidMount(){
fetch(someURL, {
method: 'GET',
headers: {
'Content-Type': 'application/json'
}
})
.then((response) => response.json())
.then((responseJson) => {
this.setState({ dataSource: responseJson })
const { email } = this.state
const value = responseJson.filter(obj => obj.email === email)[0].id
})
.catch((error) => {
console.error(error);
})
}
}
I want to retrieve all the key values from a JSON file. For example in :
{
"total_count": 6,
"incomplete_results": false,
"items": [
{
"url": "https://api.github.com/repos/Samhot/GenIHM/issues/6",
"id": 293237635,
"number": 6,
"title": "Rechercher des documents",
"user": {
"login": "Samhot",
"id": 7148311
]
}
I would like to get :
["total_count", "incomplete_results", "items", "url", "url", "number", "title", "user", "login", "id"]
I have a function which return the content of my JSON in an observable :
getConfig(): Observable<any> {
return this.http.get<any>(this.myURL);
}
After that the data are reformated with .map to get only the keys with the Object.keys() function :
merge()
.pipe(
startWith({}),
switchMap(() => {
return this.getConfig();
}),
map(data => {
return Object.keys(data.items[0]);
}
)
)
.subscribe(data => {
this.dispo = data;
});
My problem is that i get only the keys that are in the level of the JSON I told
(data.items[0]) and not the ascendants or the descendants.
Of course I can create multiple requests but it asks to know in advance the structure of the JSON, what I want is to make it generic ...
How can I do to have an array with with all of my keys regardless of the structure of the JSON ?
Thanks in advance !
You would need to do a recursive function like:
function getDeepKeys(obj) {
const keys = Object.keys(obj);
const childKeys = keys
.map(key => obj[key])
.map(
value =>
Array.isArray(value)
? getDeepKeys(value[0])
: typeof value === "object"
? getDeepKeys(value)
: []
)
.reduce((acc, keys) => [...acc, ...keys], []);
return [...keys, ...childKeys];
}
const obj = {
total_count: 6,
incomplete_results: false,
items: [
{
url: "https://api.github.com/repos/Samhot/GenIHM/issues/6",
id: 293237635,
number: 6,
title: "Rechercher des documents",
user: {
login: "Samhot",
id: 7148311
}
},
{
url: "https://api.github.com/repos/Samhot/GenIHM/issues/6",
id: 293237635,
number: 6,
title: "Rechercher des documents",
user: {
login: "Samhot",
id: 7148311
}
}
]
};
console.log(getDeepKeys(obj));
Which then you would use like map(getDeepKeys). Note that this function assumes all the items in your array have the same schema.
On one hand, I have a RESTful HAL HATEOAS collection which looks like this :
{
"page": 1,
"limit": 10,
"pages": 18,
"total": 174,
"_links": {
"self": { "href": "/users?page=1&limit=10" },
"first": { "href": "/users?page=1&limit=10" },
"last": { "href": "/users?page=18&limit=10" },
"next": { "href": "/users?page=2&limit=10" }
},
"_embedded": {
"users": [
{
"name": "bob",
"_links": { "self": { "href": "/users/1" } }
},
...
]
}
}
On the other hand, I have an Angular 2 app.
public getUsers(uri: string = this.baseURI): Observable<User> {
return this.http.get(uri)
.map(res => res.json()._embedded.users as User[])
.flatMap(d => d) // Transform the flux of arrays in flux of users
.catch(this.handleError);
} // Get only the 10th first users
What I'm trying to do have an observable of Users which will append data while _links.next != null
Modified service
public getUsers(uri: string = this.baseURI): Observable<User> {
return this.http.get(uri)
.do(res => {
const uri = JSON.parse(res._body)._links.next.href;
this.nextUri = uri ? uri : null;
})
.map(res => res.json()._embedded.users as User[])
.flatMap(d => d) // Transform the flux of arrays in flux of users
.catch(this.handleError);
}
Recursive function
loadAll(uri: string) {
read(uri)
.subscribe(
user => {
this.stockedUsers.push(user);
},
error => console.log(error),
() => {
if (this.nextUri) {
this.loadAll(this.nextUri);
}
}
);
}
Does someone know how to achieve this properly ?
I want to keep thes advantages of the RxJS flux.
UPDATE/ANSWER
Silly me ! I think I answered myself. Maybe this will help others :
public read(uri: string = this.baseURI): Observable<User> {
return Observable.create(observer => this.iteratePages(observer, uri));
}
private iteratePages(observer: Observer<User>, uri): void {
if (uri == null) { return observer.complete(); }
this.http.get(uri).subscribe(res => {
const data = res.json();
for (const user of data._embedded.users) {
observer.next(user as User);
}
const nextUri = (data._links && data._links.next) ? data._links.next.href : null;
this.iteratePages(observer, nextUri);
});
}
I'm triyng to get data from json file by a id, by I'm getting all the content.
Here the JSON:
[
{ "id": "1", "name": "Carlos", "apellidos":"López", "edad":"30", "ciudad":"Hospitalet" },
{ "id": "2", "name": "Arantxa", "apellidos":"Pavia", "edad":"24", "ciudad":"Barcelona" },
{ "id": "3", "name": "Didac" , "apellidos":"Pedra", "edad":"muchos", "ciudad":"Cornellà" },
{ "id": "4", "name": "Daniel" , "apellidos":"Farnos", "edad":"nolose", "ciudad":"Barcelona" }
]
Service:
private usersUrl = 'app/users.json';
getUser(id: String): Observable<User>{
let body = JSON.stringify(
{
"token": "test",
"content": {
"id": id
}
}
);
let headers = new Headers({ 'Content-Type': 'application/json' });
let options = new RequestOptions({
headers: headers,
body : body
});
return this.http.get(this.usersUrl, options)
.map(res => res.json()).catch(this.handleError);
}
Angular Component:
ngOnInit(){
this.route.params.subscribe(params => {
let id = +params['id'];
this.apiService.getUser(id).subscribe( (res) => { console.log(res); } );
})
}
Console.log:
Array[4]0: Object1: Object2: Object3: Objectlength: 4__proto__: Array[0]
Is the JSON bad?
Thanks.
Because you didn't filter the result by id.
.map(res => res.json())
.map(x > x.find(x => x.id == id) // filter by selected id
.catch(this.handleError);