Problem downloading an XML file in webgl

Hi

I hope I'm posting this in the right place...if not, please let me know.

The overview:
I'm making an editor that will run online and loads xml files from the same server.
Each instance needs it's own XML file (like a save game).

The details:
I'm using an editor framework, and within that I need to load the XML file and show the content to the user.
The framework doesn't have built in support for loading file automatically, nor from a server.
So I found this script to download the file:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.Networking;
5.  
6. public class SaveLoadOnline : MonoBehaviour
7. {
8.     public string LoadURL = "";
9.     public string XMLDoc;
10.  
11.     private float progress;
12.  
13.     // Start is called before the first frame update
14.     public void BeginLoad()
15.     {
16.         Debug.Log("SaveLoadOnline starting");
17.         Debug.Log("LoadURL: " + LoadURL);
18.         StartCoroutine(WWWRutine());
19.     }
20.  
21.     private IEnumerator WWWRutine()
22.     {
23.         UnityWebRequest www = UnityWebRequest.Get(LoadURL);
24.         var asyncOperation = www.SendWebRequest();
25.      
26.  
27.         while (!www.isDone)
28.         {
29.             progress = asyncOperation.progress;
30.             yield return null;
31.         }
32.  
33.         progress = 1f;
34.  
35.         if (!string.IsNullOrEmpty(www.error))
36.         {
37.             Debug.Log(www.error);
38.         }
39.  
40.         XMLDoc = www.downloadHandler.text;
41.  
42.         yield break;
43.     }
44.  
45.     // Update is called once per frame
46.     void Update()
47.     {
48.        
49.     }

And I start it using this code (in another class):

Code (CSharp):

1. var parameters = URLParameters.GetSearchParameters();
2.             string MXID;
3.             if (parameters.TryGetValue("MXID", out MXID))
4.             {
5.                 // use "MXID" here
6.                 if (MXID.Length > 0)
7.                 {
8.                     Debug.Log("URLParameter: " + MXID);
9.                     LoadFile = new SaveLoadOnline();
10.                     LoadFile.LoadURL = "http://jamsatest.dk/GC3/user/getXML.php?MXID=" + MXID;
11.                     LoadFile.BeginLoad();
12.                     Debug.Log("After BeginLoad");
13.                     var XMLDoc = LoadFile.XMLDoc;
14.                     Debug.Log("XMLDoc: " + XMLDoc.ToString());
15.                 }
16.                 else
17.                 {
18.                     Debug.Log("Empty URLParameter!");
19.                 }
20.             }
21.             else
22.             {
23.                 // no parameter with name "MXID" found
24.                 Debug.Log("NO URLParameter!");
25.             }

But just after the "LoadURL" debug message, I get this error:
NullReferenceException: Object reference not set to an instance of an object.

I've tried googling it, but I can't seem to find a solution.

But since I'm just a casual Unity-dev, I'm hoping you guys know exactly what I need to do!

 

Thanks for your reply.

The url isn't empty, and the file (getXML.php) does exist. And the xml file is in the output.

Hmm, could you point me to an example on how to do it right?

 

Thanks, I'll have a look and see if it helps me.

"too custom"? Lol, is that a polite way to say "ur code sucks"?

 

Fair enough.

I guess this isn't SO.

 

So, I've changed the code to this:

Code (CSharp):

1. public void BeginLoad()
2.     {
3.         Debug.Log("SaveLoadOnline starting");
4.         Debug.Log("LoadURL: " + LoadURL);
5.         StartCoroutine(WWWRutine(LoadURL));
6.     }
7.  
8.     private IEnumerator WWWRutine(string LoadURL)
9.     {
10.         Debug.Log("WWWRutine starting");
11.         UnityWebRequest webRequest = UnityWebRequest.Get(LoadURL);
12.         Debug.Log("After Get");
13.  
14.         // Request and wait for the desired page.
15.         yield return webRequest.SendWebRequest();
16.         Debug.Log("After SendWebRequest");
17.  
18.         string[] pages = LoadURL.Split('/');
19.         int page = pages.Length - 1;
20.  
21.         if (webRequest.isNetworkError)
22.         {
23.             Debug.Log(pages[page] + ": Error: " + webRequest.error);
24.         }
25.         else
26.         {
27.             Debug.Log(pages[page] + ":\nReceived: " + webRequest.downloadHandler.text);
28.         }
29.     }

But I still get the same error, the same place.

This entry doesn't even get shown: Debug.Log("WWWRutine starting");

Debug.Log("LoadURL: " + LoadURL); output this:
LoadURL: http://jamsatest.dk/GC3/user/getXML.php?MXID=9

And if you go to the page with a browser, you get the xml file. So what's wrong??

 

Good suggestion!

But, no dice.

The error only goes away when I disable the coroutine. And even with the error, everything else works just fine.

Soo, I move the code out, and tadaa! it works! Well, sort of work.

First it complained about CORS, so I added these headers to my .php file:

Code (CSharp):

1. header('Access-Control-Allow-Credentials: true');
2. header('Access-Control-Allow-Methods: GET, POST, PUT, OPTIONS');
3. header('Access-Control-Allow-Headers: Accept, Content-Type, X-Access-Token, X-Application-Name, X-Request-Sent-Time');
4. header('Access-Control-Allow-Origin: *');

The complete file now looks like this:

Code (CSharp):

1. <?php
2. header('Access-Control-Allow-Credentials: true');
3. header('Access-Control-Allow-Methods: GET, POST, PUT, OPTIONS');
4. header('Access-Control-Allow-Headers: Accept, Content-Type, X-Access-Token, X-Application-Name, X-Request-Sent-Time');
5. header('Access-Control-Allow-Origin: *');
6. header('Content-type: text/xml');
7. header('Content-Disposition: attachment; filename="text9.xml"');
8.  
9. echo $xml_contents;
10. exit();
11. ?>

But now it complains about ETag?? How do I get that to work?

 

Any chance of a reply today?

 

Umm, the line last contains the problem:
"But now it complains about ETag?? How do I get that to work?"

 

Well, ok. You're the expert - I just assumed that WAS the problem..

(Btw. any changes to .htaccess on the server doesn't change that error)

The REAL problem is that I still don't get the xml file.
Even though the url works fine when I try it in the browser.

My current code:

Code (CSharp):

1. Debug.Log("SaveLoadOnline starting");
2.         Debug.Log("LoadURL: " + LoadURL);
3. UnityWebRequest request = new UnityWebRequest();
4.         Debug.Log("After new");
5.  
6.         request = UnityWebRequest.Get(LoadURL);
7.         Debug.Log("After Get");
8.  
9.         // yield return request.SendWebRequest();
10.         request.SendWebRequest();
11.         Debug.Log("After SendWebRequest");
12.  
13.         if (request.isNetworkError || request.isHttpError)
14.         {
15.             Debug.Log("Error " + request.error);
16.         }
17.         else
18.         {
19.             // Show results as text
20.             Debug.Log("Success " + request.downloadHandler.text);
21.             XMLDoc = request.downloadHandler.text;
22.         }
23.         Debug.Log("After Success");
24.         return XMLDoc;

All correct debug logs are shown, only request.downloadHandler.text is empty <- do I need to use something else here to get the file??

 

Ah, of cause. Old habits die hard.

I've just checked with chrome and the browser does see the file and the content.

The response headers look like this (if that's of any help?):

Code (CSharp):

1. Access-Control-Allow-Credentials: true
2. Access-Control-Allow-Headers: Accept, Content-Type, X-Access-Token, X-Application-Name, X-Request-Sent-Time
3. Access-Control-Allow-Methods: GET, POST, PUT, OPTIONS
4. Access-Control-Allow-Origin: *
5. Cache-Control: max-age=420, private, must-revalidate
6. Connection: Keep-Alive
7. Content-Disposition: attachment; filename="text9.xml"
8. Content-Type: text/html; charset=utf-8
9. Date: Mon, 29 Jun 2020 10:38:24 GMT
10. Keep-Alive: timeout=5, max=100
11. Server: Apache
12. Transfer-Encoding: chunked
13. X-Powered-By: PHP/5.5.38

 

Ok, so I tried this:
Debug.Log("Success " + request.downloadedBytes);
XMLDoc = request.downloadHandler.data.LongLength.ToString();
Debug.Log("XMLDoc: " + XMLDoc);

And got a big fat 0 on both.

 

Code (CSharp):

1. Request URL: http://jamsatest.dk/GC3/user/getXML.php?MXID=1
2. Request Method: GET
3. Status Code: 200 OK
4. Remote Address: 185.21.40.94:80
5. Referrer Policy: no-referrer-when-downgrade

 

Ah, sneaky.

Huh, wierd. This says 0:
Debug.Log("responseCode " + request.responseCode);

 

Arg. Then we're back at beginning.

I tried putting this code in the Update function, but it doesn't fire.

Code (CSharp):

1. Debug.Log("responseCode " + request.responseCode.ToString());
2.             Debug.Log("Success " + request.downloadedBytes);
3.             XMLDoc = request.downloadHandler.data.LongLength.ToString();
4.             Debug.Log("After Success");

Sorry for being such a n00b, but how do I make Update() fire? Do I need Start()? If so, how do I get that to take a parameter(MXID) as input?

 

..and as I said, those conflicts with the rest of my code.

I may be n00bish, but not THAT n00bish.

Code (CSharp):

1.  
2. void Update()
3.     {
4.         if (request.isDone)
5.         {
6.             Debug.Log("responseCode " + request.responseCode.ToString());
7.             Debug.Log("Success " + request.downloadedBytes);
8.             XMLDoc = request.downloadHandler.data.LongLength.ToString();
9.             Debug.Log("After Success");
10.         }
11.     }

 

Ok, I've talked with the guy who has made the framework I'm using, and he says that it's not a problem with his framework.

So, I REALLY need your help.

My current code in the main thread:

Code (CSharp):

1. private void Start ()
2.         {
3.             string strMXID;
4.             strMXID = "1";
5.             Debug.Log("Before new SaveLoadOnline");
6.             LoadFile = new SaveLoadOnline();
7.             Debug.Log("after new SaveLoadOnline");
8.             LoadFile.LoadURL = "http://jamsatest.dk/GC3/user/getXML.php?MXID=" + strMXID;
9.             Debug.Log("after LoadURL");
10.             LoadFile.BeginLoad();
11.             Debug.Log("after BeginLoad");
12.             string XMLDoc = LoadFile.XMLDoc;
13.             Debug.Log("XMLDoc: " + XMLDoc);
14.             NormalReInit();
15.         }

My save/load script:

Code (CSharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5. using UnityEngine.Networking;
6. using System;
7. using MySql.Data.MySqlClient;
8. using System.Data;
9.  
10. public class SaveLoadOnline : MonoBehaviour
11. {
12.     public string LoadURL = "";
13.     public string XMLDoc;
14.  
15.     private float progress;
16.     UnityWebRequest request;
17.  
18. public void BeginLoad()
19.     {
20.         Debug.Log("SaveLoadOnline starting");
21.         Debug.Log("LoadURL: " + LoadURL);
22.         StartCoroutine(WWWRutine(LoadURL));
23.         Debug.Log("after StartCoroutine");
24.        }
25. public IEnumerator WWWRutine(string LoadURL)
26.     {
27.         Debug.Log("WWWRutine starting");
28.         request = UnityWebRequest.Get(LoadURL);
29.         Debug.Log("After Get");
30.         yield return request.SendWebRequest();
31.         Debug.Log("After SendWebRequest");
32.         if (request.isNetworkError || request.isHttpError)
33.         {
34.             Debug.Log("Error " + request.error);
35.         }
36.         else
37.         {
38.             // Show results as text
39.             Debug.Log("responseCode " + request.responseCode.ToString());
40.             Debug.Log("Success " + request.downloadedBytes);
41.             XMLDoc = request.downloadHandler.data.LongLength.ToString();
42.         }
43.         Debug.Log("After Success");
44.     }
45. }

And the output I get:


As you can see, the error stops execution just when it hits the StartCoroutine(WWWRutine(LoadURL)); line.

 

Aha.

So if I do this, it should work?

SaveLoadOnline LoadFile = gameObject.AddComponent<SaveLoadOnline>() as SaveLoadOnline;

 

Awesome! It worked!

So now I just need to pass the file back to the main script/make the main script wait until the file is ready.

I tried with this, but it doesn't stop or make it wait:

Main script

Code (CSharp):

1. private void Start ()
2.         {
3.             string strMXID;
4.             strMXID = "1";
5.             Debug.Log("Before new SaveLoadOnline");
6.             //LoadFile = new SaveLoadOnline();
7.             SaveLoadOnline LoadFile = gameObject.AddComponent<SaveLoadOnline>() as SaveLoadOnline;
8.             Debug.Log("after new SaveLoadOnline");
9.             LoadFile.LoadURL = "http://jamsatest.dk/GC3/user/getXML.php?MXID=" + strMXID;
10.             Debug.Log("after LoadURL");
11.             LoadFile.BeginLoad();
12.             Debug.Log("after BeginLoad");
13.             NormalReInit();
14.             Debug.Log("after NormalReInit");
15.             byte[] XMLDoc = LoadFile.XMLDoc;
16.             Debug.Log("RT XMLDoc: " + XMLDoc.ToString());
17.             LoadFile.StopLoad();
18.         }

My save/load script:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.Networking;
5. using System;
6. using MySql.Data.MySqlClient;
7. using System.Data;
8.  
9. public class SaveLoadOnline : MonoBehaviour
10. {
11.     public string LoadURL = "";
12.     public string XMLDocLength;
13.     public byte[] XMLDoc;
14.     public bool Stop;
15.  
16.     private float progress;
17.     UnityWebRequest request;
18.    
19.  
20.     public void BeginLoad()
21.     {
22.         Stop = false;
23.         Debug.Log("SaveLoadOnline starting");
24.         Debug.Log("LoadURL: " + LoadURL);
25.         StartCoroutine(WWWRutine(LoadURL));
26.         Debug.Log("after StartCoroutine");
27.     }
28.  
29.     public void StopLoad()
30.     {
31.         Stop = true;
32.     }
33.  
34.     public IEnumerator WWWRutine(string LoadURL)
35.     {
36.         Debug.Log("WWWRutine starting");
37.         request = UnityWebRequest.Get(LoadURL);
38.         Debug.Log("After Get");
39.  
40.         yield return request.SendWebRequest();
41.  
42.         Debug.Log("After SendWebRequest");
43.  
44.         if (request.isNetworkError || request.isHttpError)
45.         {
46.             Debug.Log("Error " + request.error);
47.         }
48.         else
49.         {
50.             // Show results as text
51.             Debug.Log("responseCode " + request.responseCode.ToString());
52.             Debug.Log("Success " + request.downloadedBytes);
53.             XMLDocLength = request.downloadHandler.data.LongLength.ToString();
54.         }
55.         Debug.Log("After Success");
56.  
57.         if (Stop == true)
58.         {
59.             yield break;
60.         }
61.     }
62.    
63.     // Update is called once per frame
64.     void Update()
65.     {
66.         if (request.isDone)
67.         {
68.             Debug.Log("responseCode " + request.responseCode.ToString());
69.             Debug.Log("Success " + request.downloadedBytes);
70.             XMLDoc = request.downloadHandler.data;
71.             Debug.Log("After Success");
72.         }
73.     }
74. }