Read and write locale file with WebGl (via php)

Unity Engine
,
1

I am trying to store data locally and retrieve local data via a WebGl application. It does not work via System IO for some security reasons (I have read). I have tried with WWW. It works without problems to write a local file via a php page/file that I call. In Unity editor it works to write and also read the local file using this code. But in WebGl only writing works. However, I can not read the file in webGL.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Networking;
using System.Text.RegularExpressions;
using UnityEditor;

public class Writetofile : MonoBehaviour
{
    public Text Test;

    private void OnGUI()
    {
        GUIStyle buttonStyle = new GUIStyle(GUI.skin.button);
        buttonStyle.fontSize = 25;
        if (GUI.Button(new Rect(10, 10, 450, 80), "Send Information To File", buttonStyle))
        {
            Test.text = "test";
            StartCoroutine(sendTextToFile());
        }
        if (GUI.Button(new Rect(10, 100, 450, 80), "Send Information To File", buttonStyle))
        {
            StartCoroutine(getTextFromFile());
        }
    }

    IEnumerator sendTextToFile()
    {
        bool successfull = true;

        WWWForm form = new WWWForm();
        form.AddField("name", "Joe Bloggs");
        form.AddField("age", "32");
        form.AddField("score", "125");
        WWW www = new WWW("http://localhost:9000/fromunity.php", form);

        yield return www;
        if (www.error != null)
        {
            successfull = false;
        }
        else
        {
            Debug.Log(www.text);
            successfull = true;
        }
    }

    IEnumerator getTextFromFile()
    {
        bool successfull = true;
        WWWForm form = new WWWForm();
        WWW www = new WWW("http://localhost:9000/tounity.php", form);
        yield return www;
        if (www.error != null)
        {
            successfull = false;
        }
        else
        {
            Test.text = "" + www.text;
           Debug.Log(www.text);
            successfull = true;
        }
    }
}
2

What is the error you are having? Try using UnityWebRequest instead of the WWW class if that helps?