B4J Question How to display in a webview images stored into MySql DB

[lucdrb]

HI,

I've a MySql database where I store images in blob format. The images are from different users.
I've to mix text and images in the final result, for this purpose I thinking of using a webview.

The text should be create with an HTMLEditor.
But for the images from the database, I don't have any idea to display it in the webview.

Your help should be welcome.

Luc

 

[EnriqueGonzalez]

Hello!

to store the images in mysql

private Sub ImageToBlob(dir As String, f As String) As String
        Dim InputStream1 As InputStream
        InputStream1 = File.OpenInput(dir,f)
      
        Dim su As StringUtils
      
        Dim OutputStream1 As OutputStream
        OutputStream1.InitializeToBytesArray(1000)
        File.Copy2(InputStream1, OutputStream1)
        Dim Buffer() As Byte 'declares an empty array
        Buffer = OutputStream1.ToBytesArray
        Return su.EncodeBase64(Buffer)
End Sub

'use it like this:
SQLInterno.ExecNonQuery2("INSERT INTO table (text, image) VALUES (?,?)",Array("test",ImageToBlob(File.DirApp,"name")))

and retrieve them like this:

public Sub blobToIO(bySt As String) As InputStream
    Dim su As StringUtils
    Dim by() As Byte = su.DecodeBase64(bySt)
  
    Dim InputStream1 As InputStream
    InputStream1.InitializeFromBytesArray(by, 0, by.Length)
'    InputStream1.Close  
    Return InputStream1
End Sub

'and use it like this:
    Dim r As Image
    r.Initialize2(sql1.execquerysingleresult("SELECT image FROM table WHERE text = 1")

 

[Erel]

Why are you using base64 strings???

Use BytesToFile and FileToBytes: https://www.b4x.com/android/forum/threads/b4x-bytes-to-file.70111/#content

Assuming that this is a UI application then you should avoid using synchronous SQL methods with remote databases.
The best way is to use ConnectionPool from jServer library.

 

[lucdrb]

Thanks Enrique
But I'm interrested in the next step:

Display the image in a webview.

Luc

 

[Erel]

Save the image to a file and then show it like you show any image file.

Sub Process_Globals
   Private fx As JFX
   Private MainForm As Form
   Private WebView1 As WebView
End Sub

Sub AppStart (Form1 As Form, Args() As String)
   MainForm = Form1
   MainForm.RootPane.LoadLayout("1") 'Load the layout file.
   MainForm.Show
   WebView1.LoadHtml($"
   <h1>Title</h1>
   <img src="${File.GetUri("c:\temp", "1.JPG")}"/>
   
"$)
   
End Sub

 

[lucdrb]

Thank you

Luc