Ionic 4 POST to PHP backend - php

Question

I'm trying to POST data to a PHP backend and receive back the values and push it into an array. Hence, I created a function to do just that. However, I'm not to change the API on the backend (written in PHP). So I cannot change it to suit my normal methods of using POST.
This is my function
test() {
let data = "method=getThis" + "&db=myDatabase"
this.http.post("API URL", data).subscribe(data => {
this.result = data; // get data in result variable
this.items = JSON.stringify(this.result); // then convert data to json string
// console.log(this.items);
this.allData = JSON.parse(this.items); // parse json data and pass json string
// console.log(this.allData.length); // got result of particular string
this.array = [];
for (var i = 0; i < this.allData.length; i++) {
this.array.push({
data1: this.allData[i].data1,
data2: this.allData[i].data2,
})
}
console.log(this.array[0])
})
}
And this is an example function on the backend
else if($_POST['method']=="getThis"){
global $conn;
mysqli_select_db($conn, $_POST['db']);
$name="";
$result=array();
$r=mysqli_query($conn,"select data1,data2 from table");
while ($rs = mysqli_fetch_array($r,MYSQLI_ASSOC)){
array_push($result,$rs);
}
echo json_encode(array("result"=>$result));
}
So how do I actually get it to post? I'm stuck here. I usually post with JSON and then decode the JSON on the backend. But this time around I'm not developing the backend and not changing it so gotta use the one provided.
Posting using POSTMAN with this
method=getThis&db=myDatabase
works well. Not sending JSON just a text. So how do I actually achieve this in Ionic.

Answer 1

You could try it that way. It works for me:
First import:
import { map } from "rxjs/operators/map";
Your function:
test() {
let data = "method=getThis" + "&db=myDatabase"
this.http.post("API URL", data).pipe(
map(res => res.json())
).subscribe(response => {
//Here your code
// 'response' is json
});
}

Answer 2

Since the data you are sending is in plain text, you will need to add a header mentioning the content type.
import { HttpHeaders } from '#angular/common/http';
const httpOptions = {
headers: new HttpHeaders({
'Content-Type': 'text/html'
})
};
this.http.post("API URL", data, httpOptions).subscribe()

Answer 3

PHP side should be return JSON and told browser content type is application/json, please test your code base on one simple page.
//demo.php
<?php
$data = ['message' => 'Hello world.'];
header("Content-Type: application/json; charset=UTF-8");
//If allow cross domain and not configration in Ngix/Apache
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS");
header("Access-Control-Allow-Headers: Accept-Encoding, X-Requested-With, Content-Type, Origin, Accept, Authenticationtoken");
echo json_encode($data);
And please try http access demo.php again.