description

# postFormData method Null safety

Future<HttpRequest> postFormData (

1. String url,
2. Map<String, String> data,
3. {bool? withCredentials,
4. String? responseType,
5. Map<String, String>? requestHeaders,
6. void onProgress(
   1. ProgressEvent e
   )}

)

Makes a server POST request with the specified data encoded as form data.

This is roughly the POST equivalent of getString. This method is similar to sending a FormData object with broader browser support but limited to String values.

If `data` is supplied, the key/value pairs are URI encoded with Uri.encodeQueryComponent and converted into an HTTP query string.

Unless otherwise specified, this method appends the following header:

    Content-Type: application/x-www-form-urlencoded; charset=UTF-8

Here's an example of using this method:

    var data = { 'firstName' : 'John', 'lastName' : 'Doe' };
    HttpRequest.postFormData('/send', data).then((HttpRequest resp) {
      // Do something with the response.
    });

See also:

- request

## Implementation

    static Future<HttpRequest> postFormData(String url, Map<String, String> data,
        {bool? withCredentials,
        String? responseType,
        Map<String, String>? requestHeaders,
        void onProgress(ProgressEvent e)?}) {
      var parts = [];
      data.forEach((key, value) {
        parts.add('${Uri.encodeQueryComponent(key)}='
            '${Uri.encodeQueryComponent(value)}');
      });
      var formData = parts.join('&');

      if (requestHeaders == null) {
        requestHeaders = <String, String>{};
      }
      requestHeaders.putIfAbsent('Content-Type',
          () => 'application/x-www-form-urlencoded; charset=UTF-8');

      return request(url,
          method: 'POST',
          withCredentials: withCredentials,
          responseType: responseType,
          requestHeaders: requestHeaders,
          sendData: formData,
          onProgress: onProgress);
    }