Bug 20539 - WebView delegate methods not called in custom renderer
Summary: WebView delegate methods not called in custom renderer
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 1.0.6188
Hardware: PC Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2014-06-11 15:23 UTC by John Miller [MSFT]
Modified: 2015-01-19 04:34 UTC (History)
5 users (show)

Is this bug a regression?: ---
Last known good build:

Test Case Project (2.52 MB, application/zip)
2014-06-11 15:23 UTC, John Miller [MSFT]

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Description John Miller [MSFT] 2014-06-11 15:23:36 UTC
Created attachment 7045 [details]
Test Case Project

## Overview: 

    When implementing a WebViewRenderer, overridden delegate methods are not called. 

## Steps to Reproduce: 

    1. Run the attached sample on iOS.

## Actual Results: 

    The overridden ShouldStartLoad method is not called.

## Expected Results: 

    Method should be called to have a way to implement similar functionality to native APIs with ShouldStartLoad, etc. 

## Build Date & Platform: 

    Xamarin.Forms 1.0.6186

## Additional Information: 

   There are also a number of Events available in UIWebView (LoadStarted, LoadFinished, etc) which are not called. This might be by design, but it is unclear why it does not work.
Comment 3 Udham Singh 2014-08-08 08:44:32 UTC
I have checked this issue with the steps provided in bug description and observed that overridden 'ShouldStartLoad' method is not called, when we run the iOS application.

Screencast : http://screencast.com/t/IaEiaxCbdtw

Enviroment Info :

=== Xamarin Studio ===

Version 5.2 (build 386)
Installation UUID: 011d70a5-dede-428b-ab04-ef451c2e539d
	Mono 3.6.0 ((no/f540f8a)
	GTK+ 2.24.23 (Raleigh theme)

	Package version: 306000039

=== Xamarin.Android ===

Version: 4.14.0 (Enterprise Edition)
Android SDK: /Users/MM/Desktop/android-sdk-macosx
	Supported Android versions:
		2.1   (API level 7)
		2.2   (API level 8)
		2.3   (API level 10)
		3.1   (API level 12)
		3.2   (API level 13)
		4.0   (API level 14)
		4.0.3 (API level 15)
		4.1   (API level 16)
		4.2   (API level 17)
		4.3   (API level 18)
		4.4   (API level 19)
Java SDK: /usr
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode)

=== Apple Developer Tools ===

Xcode 5.1 (5084)
Build 5B130a

=== Xamarin.iOS ===

Version: (Enterprise Edition)
Hash: 606f31a
Build date: 2014-08-01 15:27:48-0400

=== Xamarin.Mac ===

Version: (Enterprise Edition)

=== Build Information ===

Release ID: 502000386
Git revision: e6a54dee5376e6e7a2d9982695b060fddc09e65d
Build date: 2014-08-04 14:03:28-04
Xamarin addins: 2b5a5c26ac2ee74c6e91a8d24ef44d0ca9cb74d0

=== Operating System ===

Mac OS X 10.9.2
Darwin MacMini.local 13.1.0 Darwin Kernel Version 13.1.0
    Thu Jan 16 19:40:37 PST 2014
    root:xnu-2422.90.20~2/RELEASE_X86_64 x86_64
Comment 4 christine.blanda 2014-08-08 10:37:25 UTC
There are two changes that need to be made to the sample code to get this to work.  First, the code in the CustomWebViewRenderer should be in the OnElementChanged event, not in the constructor (and base.OnElementChanged should be called first).  Second, you need to remove the LoadStarted code because you can only use events or delegates, not both, so the definition of LoadStarted disables the Delegate. and of course un-comment delegate assignment. the  After making those changes ShouldStartLoad will be called.
Comment 5 Jason Smith [MSFT] 2015-01-19 04:34:30 UTC
If you need to change how the delegate works a custom renderer is suggested.