Services
Callback agent
Snipshot has two ways of sending pictures to a site. Either the Snipshot server makes a request, or the user's browser makes a request. This is determined by setting the parameter snipshot_callback_agent to either "snipshot" or "user". The different properties of each are listed below. By default, the callback agent is set to "snipshot".
| snipshot | user | |
|---|---|---|
| HTTP method | POST | GET |
| Output type | image data | URL to image |
| Passthru data | hidden from client | visible to client |
| snipshot_callback_redirect | valid | not valid |
| Maintains user session | no | yes |
Each callback agent is best for different situations. For sites where a user edits an image inside a private account, the user is the best agent to initiate the callback, because any session cookies will be passed along with the callback request. In this situation, you can rely on a site's existing authentication procedure to validate the request. For sites where there is a public upload form or where identification info can be passed into Snipshot with the image, the best callback agent is the Snipshot server, because it is easier to implement and it is more flexible.
If you have any questions about the two ways of making a callback, email us at help@snipshot.com.