I have a web page with a WebCanvas on it that I draw a string into using the paint event. It works as expected in OS X but in Linux it flickers and then disappears when the page is shown. If I use a WebDialog on the same page as the WebCanvas in Linux the app becomes unresponsive once the WebDialog is shown. Any idea what is causing this behavior?
Offhand, no. What distro/version of Linux and what browser are you using?
I didn’t have the problem in Firefox so it’s looking like this is a problem specifically with Safari.
But Safari isn’t available on Linux.
The web app is running on a Linux server. The problem occurs when it is viewed in Safari on a Mac. The problem does not occur if the web app is running on an OS X server. I haven’t yet isolated the problem but it appears to be either a cache or cookie problem that affects Safari when it is accessing a web app running on a Linux server.
This is like saying that you saw someone driving a car with four wheels. What distro? 32 or 64 bits? shared hosting?
It would also be helpful to know if it was running as CGI or Standalone on both systems.
It’s running as CGI. It’s hard to figure what might be causing the problem. It doesn’t happen in Chrome or Firefox, only Safari. Clearing the Safari cache will sometimes clear the problem but not consistently. The web app is here if you want to take a look:
https://www.capaho.com/cgi-bin/ContactCapaho/contactcapaho.cgi
I can’t get to that URL at all.
[quote=126110:@Carl Hogue]It’s running as CGI. It’s hard to figure what might be causing the problem. It doesn’t happen in Chrome or Firefox, only Safari. Clearing the Safari cache will sometimes clear the problem but not consistently. The web app is here if you want to take a look:
https://www.capaho.com/cgi-bin/ContactCapaho/contactcapaho.cgi[/quote]
Chrome 36 and Safari 7.1 display identically. Where is supposed to be the disappearing string ?
Well I can see the error this morning. I’m losing connection to the server almost immediately after connecting. I can’t even make the dialog disappear.
Yes, that’s exactly the problem. The canvas flickers and disappears and the app hangs with the dialog window open but I’m only seeing the problem in Safari with the app running on a Linux server.
There is a canvas above the cancel button that displays an 8-digit number. The problem is somewhat intermittent but when it occurs that canvas flickers and disappears and the app hangs with the dialog window open, then the app becomes unresponsive until it times out.
Well, I’m not going to be able to debug this without seeing your code. What I can tell you is that the browser thinks that the responses are getting out of order and is requesting a refresh, over and over and over.
That’s helpful. I’ll take a look at my code with that in mind and see if I can find anything. If not, I’ll post the code.
You can attach your project to a private Feedback case if you’d prefer. That would be best for us.
I get it. It is the captcha one has to copy. Amazingly enough, I just tried this morning and now the bug manifests. But I do not have the app hanging. If I click send the window appears asking for a subject category, but I can dismiss it.
Just an idea : could an Image Well be used instead and have a chance to mitigate the bug until it is fixed by Xojo ?
First of all, I’m still not convinced this is our bug. If it were, I’d expect it to be doing this for everyone who uses a WebCanvas, so I still need to see that code, even if it’s just for the captcha control.
As far as an image well, don’t know. It probably depends on your requirements.
Sorry, I assumed without thinking it through.
I went back to the page which exhibits the issue, then went to Safari developer web console, and click “Inspect”. Seems the canvas is there indeed :
in /DOM Tree/html/body/div#XojoContainer/div#XojoPages/div#SVJPTIH.Style1/div#Zwn3kyVh/canvas#Zwn3kyVh_canvas
[code]
But it contains no picture. Could it be that the bug lies in the generation of the picture, as it seems the control is indeed part of the page code ?
Then the issue would manifest whatever the control used to display it.
[quote=126407:@Michel Bujardet]But it contains no picture. Could it be that the bug lies in the generation of the picture, as it seems the control is indeed part of the page code ?
Then the issue would manifest whatever the control used to display it.[/quote]
Just because there’s no tag for it doesn’t mean there’s no picture. Canvases don’t draw that way.