Sharing a screenshot to a developer defined URL
In Layar, users can share screenshot on Facebook and Twitter. It is also possible to have users share a screenshot to a URL of a developer's choosing.
Key Steps to Implement
Configuration on the publishing site
The URL to which the screenshot will be posted is configurable on the Layar publishing site, in the same tab as the API endpoint URL.
If a URL is entered there, a new sharing option will appear on the "screenshot sharing dialog" in the Layar client after a screenshot is taken, next to the Facebook and Twitter options.
How does it work ?
When selected by the user, Layar will upload the screenshot file to the specified URL as if it were a file uploaded through a web form. In other words, the request will be an HTTP POST with MIME type multipart/form-data. Most web platforms/frameworks will handle this automatically. For example, in PHP uploaded files will be placed in the $_FILES array.
The following parameters are included in the call to the developer supplied URL:
|message||string||The message that the user entered to go with the screenshot|
|screenshot||file||The screenshot the user took|
The latitude and longitude where the screenshot was taken are included as EXIF data in the screenshot file. There are EXIF libraries for PHP, Python and other languages.
If you need to manually decode the HTTP request, an example body of a screenshot POST call would look like this:
------------ThIs_Is_tHe_bouNdaRY_$ Content-Disposition: form-data; name="message" This screenshot was taken with the Layar Reality Browser! ------------ThIs_Is_tHe_bouNdaRY_$ Content-Disposition: form-data; name="screenshot"; filename="filename.jpg" Content-Type: image/jpeg <binary screenshot data>------------ThIs_Is_tHe_bouNdaRY_$--