B4R Question Simple Web Server - AStream_Error always triggered, why?

[miker2069]

I'm trying to implement a simple web-server using NodeMCU. It's very simple, one connection at any time. I'm porting a project from regular arduino C to B4R. So right now just a simple, receive some data and send a response. With the following code, it all seems to work with the exception that AStream_Error event is always triggered for every connection. I can get data and respond okay but every time AStream_Error is triggered. I figured I could use LastException but that doesn't seem like it's availble in B4R - I am using v2.2. What am I missing?

I cobbled together this example from the forum and examples...thank you for any insight.

Private Sub AppStart
    Dim ssid As String
    Dim password As String
   
    ssid = "xxx"
    password = "xxx"
   
   
   Serial1.Initialize(115200)
   Log("AppStart")
   pin5.Initialize(14, pin5.MODE_OUTPUT)
  
    If wifi.Connect2(ssid,password) Then 'change to your network SSID (use Connect2 if a password is required).
        Log("Connected to wireless network."  + ssid)
        Log("My ip: ", wifi.LocalIp)
    Else
        Log("Failed to connect.")
        Return
    End If
   
    server.Initialize(80, "server_NewConnection")
    server.Listen
   
   'Timer1.Initialize("Timer1_Tick", 1000) '1000ms = 1 second
   'Timer1.Enabled = True
End Sub

Sub Server_NewConnection (NewSocket As WiFiSocket)
    Log("Client connected")
    astream.Initialize(NewSocket.Stream, "astream_NewData", "astream_Error")

End Sub

Sub AStream_NewData (Buffer() As Byte)
    Log("Received from server: ", Buffer)
   
    'astream.Write("HTTP/1.1 200 OK").write(CRLF)
    'astream.Write("Content-Type: text/html").Write(CRLF).Write(CRLF)
    'astream.Write("<b>Hello World</b><br/><a href=""https://www.b4x.com"">B4X</a>")
   
    Dim bc As ByteConverter
    Dim s As String
    s = "HTTP/1.1 200 OK\r\n"
       
    Dim bytesa() As Byte
       
    bytesa = bc.ObjectToBytes(s,s.Length)
    astream.Write(bytesa)
       
    s = "Content-Type: text/html\r\n"
    bytesa = bc.ObjectToBytes(s,s.Length)
    astream.Write(bytesa)
       
    CallSubPlus("CloseConnection", 100, 0)
   
'    Dim bc As ByteConverter
   
    'Dim data As String
   
    'data = bc.StringFromBytes(Buffer)
   
    'Dim be(10) As Object
    'Dim data() As Object = ser.ConvertBytesToArray(Buffer,be)
   
    'Log("-------->Received:" + data)
    'For Each o As Object In data
    '    Log(o)
    'Next
   
End Sub

Sub CloseConnection(u As Byte)
    Log("writing")
    server.Socket.Stream.Flush
    server.Socket.Close
End Sub

Sub AStream_Error
    Log("Error")

    server.Listen
End Sub

 

[Erel]

1. You don't need to use bc.ObjectTypeBytes to convert a string to an array of bytes.
2. There is no \r\n in B4R. Use CRLF instead.

AStream_Error will be raised when the connection is closed.

Why are you building a web server? Do you want to access it from the browser?

 

[miker2069]

1. You don't need to use bc.ObjectTypeBytes to convert a string to an array of bytes.
2. There is no \r\n in B4R. Use CRLF instead.

AStream_Error will be raised when the connection is closed.

Why are you building a web server? Do you want to access it from the browser?

I was also using:

astream.Write("HTTP/1.1 200 OK").write(CRLF)
astream.Write("Content-Type: text/html").Write(CRLF).Write(CRLF)

As well - my main question is that Astream_Error seemed to get triggered all the time. Which you answered it's called on closing the connection, which is fine, I can just ignore it

I'm not trying to necessarily communicate with a browser (I know that's problematic since browsers can make multiple simultaneous connections to the ESP8266 which would cause issues). It was more proof of concept as I am porting over a couple Arduino projects to B4R and wanted to reproduce the current http connection approach I was using. I'm definitely going to use something much lighter since I really don't need it to use the http protocol.

Thank You for your help!

 

[Erel]

I'm definitely going to use something much lighter since I really don't need it to use the http protocol.

Check this example: https://www.b4x.com/android/forum/threads/esp-configurator-based-on-b4rserializator.81452/#content

 

[miker2069]

Check this example: https://www.b4x.com/android/forum/threads/esp-configurator-based-on-b4rserializator.81452/#content

I just fired this up, and a tear ran down my cheek - this is a work of art! So simple and powerful....I'm giddy with the possibilities!