Check if httpImageSouce has loaded

How-to Discussions
1

I have a list of 50+ images in a catalog. I recieve a json with the image URLs and then load them with this.


									<StackPanel Orientation="Horizontal">
										<Each Items="{contents}" Limit="99">
											<Rectangle Height="140" Margin="0,0,10,0" Width="103" Clicked="{OpenDetails}" Background="Black">
												<Each Items="{posters}" Limit="1">
													<Image Height="140" Width="103" StretchMode="UniformToFill" MemoryPolicy="QuickUnload">
														<HttpImageSource Error="{errorHandler}" Density="1" Url="{xxsmall}" Policy="QuickUnload"/> 
													</Image>
												</Each>
											</Rectangle>
										</Each>
									</StackPanel>

Now some items don’t load, and since this is random I suppose that it’s a timeout for fireing so many requests.
I thought that not loading would fire the Error event, but it doesn’t. Is there any way I can check if the image has loaded successfuly?

2

There’s no reason the the Error handler wouldn’t be called if an error occurs. We don’t use that much directly in UX though, instead we tend to use the WhileFailed trigger. Try that and see if you can at least detect that they’ve failed that way.

It’s possible the request is somehow hanging instead of failing. I’m not sure what the timeout policy is at the moment. I’ll file an issue to investigate this.

3

What platform(s) does the issue occur on?

4

Both android and iphone have this.

About the WhileFailed trigger… I can’t put it inside the HttpImageSource tag, so where would it go?

5

I’m also a developer in this project, if you have GitHub users I can add you to the private repo so you can check the source.
How do we catch the error with the WhileFailed?
I tried adding

 <WhileFailed>								    
                <Change testText.Value="Error" />
</WhileFailed>

Inside the Image and

 <Text ux:Name="testText" Color="White" Alignment="Center" />

as the example provided in the docs https://www.fusetools.com/docs/fuse/triggers/whilefailed but we receive a “cannot be accessed from this scope.”

6

That error is typically emitted when you attempt to access a ux:Name object outside of the current ux:Class being defined.

Unfortunately with WhileFailed there is no way to get at the error message. It goes on the Image, not the ImageSource. As long as Error isn’t working correctly there is no way to get at the error message.