Webview not working

[Brad]

The webview is a no-brainer but for some reason I can't get it to display any web pages. I was messing around with it and trying to load google but nothing loads.

I have a button that loads the url then displays the url in a label. For some reason the first time I click the button, the url is NULL.. Not till I click it the 2nd time will the url display correctly. :BangHead:

 

[alfcen]

Please post the code for all to see.

 

[Brad]

Pretty basic code.

Sub Globals
   Dim Button1 As Button
   Dim WebView1 As WebView
   Dim Label1 As Label
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("main")
   WebView1.Initialize("WebView")

End Sub

Sub Button1_Click
   WebView1.LoadUrl("http://www.google.com")
   label1.Text = "URL: " & WebView1.Url
End Sub

 

[alfcen]

If you have placed the WebView in the Designer, then you do not need
WebView1.Initialize("WebView")

If not, then change it to:
WebView1.Initialize("WebView1")

 

[Brad]

:sign0161: Thanks..still new to B4A :sign0104:

The url property still shows NULL after the first click..Not until the 2nd click will the page load and the url field displays correctly.

 

[Erel]

The Url property returns the current url displayed. It will be available when the page finishes loading.

 

[alfcen]

Confirmed. It appears as if WebView.Url is not available until a page is fully loaded. I can't find any event that is raised as a page is loaded, such as

Sub WebView1_Ready
Label1.text = WebView1.Url
End Sub

 

[Erel]

Such an event will be added in the next update.

 

[alfcen]

This is certainly not a critical issue.
You could use a timer, however, one doesn't know in advance how long it takes a page to load:

Sub Globals
   Dim Button1 As Button
   Dim WebView1 As WebView
   Dim Label1 As Label
   Dim Timer1 As Timer
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("layout_main")
   Timer1.Initialize("Timer1",2000)
End Sub

Sub Button1_Click
   WebView1.LoadUrl("http://www.google.com")
   Timer1.Enabled = True
End Sub

Sub Timer1_Tick
   Label1.Text = "URL: " & WebView1.Url
   Timer1.Enabled = False
End Sub

 

[Erel]

You can check if the URL is null and keep waiting:

Sub Timer1_Tick
    If WebView1.Url = Null Then Return

Also note that timers should be declared as process global variables and be initialized when FirstTime is true (in Activity_Create).
Otherwise a new timer will be created each time the activity is recreated.

Sub Process_Globals
    Dim Timer1 As Timer
End Sub

Sub Globals
    Dim WebView1 As WebView
End Sub

Sub Activity_Create(FirstTime As Boolean)
    If FirstTime Then
        Timer1.Initialize("Timer1", 500)
    End If
  ...

 

[alfcen]

That is elegant, Erel, thanks a lot!

 

[Brad]

A timer would be good at setting a timeout so if the page won't load in say 30 seconds, the timer event could display a message saying that the server wasn't responding instead of having the user wait. Now, what happens if the url isn't valid?

 

[Erel]

The user will see the default "page not available" page. Unfortunately it is very difficult to get such errors with the WebView API (which behaves differently than documented in this case).