Hi All...
I've tried both Ken and Gerry's suggestions for downloading images in the
background via a URL.
In Ken's example, I was able to get the an images downloaded to a img object,
however when navigating to another card LiveCode started behaving strangely and
it would lock up for a minute, or two, and then proceed to give me an
assortment of URL Errors about exceeding the 4000 limit etc., etc. ending with
a ForceQuit.
In Gerry's example I managed to download a single image to a folder, but could
not loop through my list of image URLs in order to download each one.
I attempted to combine both Ken and Gerry's examples, in order to prevent the
error messages I was receiving in Ken's first example. However, it is not
working...yet.
Here is what I have:
on mouseUp
send "downloadImage 1" to me in 0 milliseconds
end mouseUp
on downloadImage idx
if idx <= the number of lines in cd fld "imageURLs" then
set the itemDel to tab
put item 1 of line idx of cd fld "imageURLs" into tURL
set the itemDel to "/"
put the last item of tURL into tImagename
libUrlDownloadToFile tURL, specialfolderpath ("Documents") & "/WhaleImages/"
& tImagename
send "downloadImage "&(idx+1) to me in 0 milliseconds
end if
end downloadImage
Any suggestions welcome...
Thank you!
John Patten
SUSD
On Feb 21, 2012, at 4:20 AM, Ken Corey wrote:
> Sure, why not? Let's assume that this is all kicked off from a button press:
>
> -- I assume you have your URLs in a list
>
> on mouseUp
> -- send in 0 milliseconds means call downloadImage as soon
> -- as this handler is done
> -- I'd create placeholder graphics where the images might
> -- go once downloaded, and then you can put them into a list
> send "downloadImage 1" to me in 0 milliseconds
> end openCard
>
> on downloadImage idx
> -- check to see if we've fallen off the end of the list.
> if idx <= the number of lines of listOfURLs then
> get URL "http://blah.com/image.gif";
> -- do something terribly clever to display them to the user.
> -- e.g. replace the placeholder images above for item idx
> --
> -- queue up the next image for download
> send "downloadImage "&(idx+1) to me in 0 milliseconds
> end if
> end downloadImage
>
> So, your app interface should be happily trundling along responding to user
> input, while the images are being downloaded. Increase the '0 milliseconds'
> for more responsiveness.
>
> This assumes you want the images to come down one at a time. You /could/
> queue up more than one at a time by sending 'downloadImage' to yourself
> multiple times, but then you'd have to get fancier managing the index.
>
> You probably don't want to issue all the sends at the same time, because
> unless you have a monster fat pipe none of them will come down at any
> rational rate of speed.
>
> You might also want to think about caching the image somehow. Check for its
> existance before the get, and avoid hitting the net at all. (Of course, that
> means you have to let the user clear the cache, limit the size to which it
> grows, etc.)
>
> -Ken
>
>
>
> On 19/02/2012 05:40, johnpat...@me.com wrote:
>> I'm looking to use the Flickr API search routine to return the latest
>> images for a specific tag. I will probably limit it to the 10 or 20 most
>> recent images. I can create the resulting URL to the images from the
>> resulting XML, and set the file name of an image to that URL, looping
>> through the list of images, but I'm curious as to what would be best
>> practice would be to download these images in the background? Ideally I
>> would like the user to be able to use the simulated swipe routines
>> between the images.
>>
>> The only thing I can think of is downloading the images in the
>> background as soon as the iOS app is launched. Could a script like this
>> be launched at openStack and run in the background?
>
> _______________________________________________
> use-livecode mailing list
> use-livecode@lists.runrev.com
> Please visit this url to subscribe, unsubscribe and manage your subscription
> preferences:
> http://lists.runrev.com/mailman/listinfo/use-livecode
_______________________________________________
use-livecode mailing list
use-livecode@lists.runrev.com
Please visit this url to subscribe, unsubscribe and manage your subscription
preferences:
http://lists.runrev.com/mailman/listinfo/use-livecode
![http://blah.com/image.gif"](http://blah.com/image.gif"){kind=link}