Unable to post variable through http.post() in angular 4

Question

I'm getting issue in angular 4 .... I am building hybrid app using ionic 3.

I have to use php as server side language for APIs, I am having issue in posting variables to http.post() request ...

variables are not passed to php file.

Method I'm using to call API from home.ts is:

var json = {var1: 'test'};

var params = 'json='+json;

let headers = new Headers();

headers.append('Content-Type', 'application/json');

http.post("http://example.com/infoarray.php", params, headers ).subscribe (re => {
console.log(re)
})

I'm able to get response from API just fine but the problem is I can't pass the value of variable 'var1' to my API on infoarray.php I'm encoding the request to json ... but didn't get variables

Answer 1

1. Check your PHP code, may be you are missing to get JSON content from Post.

    $data = json_decode(file_get_contents('php://input'), true); print_r($data); echo $data["param"]; 

2. Otherwise try to add params in form data

    let headers = new Headers({ 'Content-Type': 'application/x-www-form-urlencoded' }); let options = new RequestOptions({ headers: headers }); // Create a request option let url = "SERVER_URL"; let body = 'param1='+value1+'&param2=' +value2; this.http.post(url, body, options) 

Answer 2

Use JSON.stringify() method while processing the params:

var json = {var1: 'test'};

var params = 'json='+JSON.stringify(json);

Answer 3

Your params = 'json='+json will actually result to this: "json=[object Object]". That's because you didn't stringify the object first, which is done as so:

var params = 'json=' + JSON.stringify(json); // "json={"var1":"test"}"

Answer 4

Use JSON.stringify() and put your headers in RequestOptions class

let headers = new Headers();
    headers.append('Content-Type', 'application/json');
let requestOpt = new RequestOptions({ headers: headers });
    const bodyStr = JSON.stringify({var: value});

this.http
    .post(this.vocabularyPostUrl, bodyStr, requestOpt)

Answer 5

You have to stringify the object. Otherwise you will end in getting "[object][object]" rather than "{var1: 'test'}" .

JSON.stringify(json);