Google Calendar allows client applications to view and update calendar events in the form of Google Data Protocol feeds. Your client application can use the Google Calendar Data API to create new events, edit or delete existing events, share calendar and query for events that match particular criteria.
To request, add, delete or share data, your application needs an authentication token. You should use OAuth as your application’s authentication method.
This blog describes, how to modify Google Calendar Access Control Lists (ACLs) using the raw protocol. An access control list identifies the set of users with whom a given calendar is shared, and the level of access for each user (such as read-only access, full access, and so on).
Specifically, an ACL is a list of access rules. Each access rule specifies a “scope” (a person or set of people) and then associates a “role” (an access level) with that scope. The ACL for each calendar is available as a Data API feed. Each entry in the feed defines a single access rule.
Google Calendar does not support query parameters on requests for ACL feeds.
A requester with permission to modify the access control list can add a new ACL rule by posting a new entry to the ACL feed’s POST URI. The entry should contain the following elements or properties:
You could send a POST request to the following URI, after authentication:
Following, is the example to share the Google calendar to another outside the domain:
If the specified <gAcl:scope> does not already have a role defined (or, equivalently, if the role for that scope is currently none), then Calendar creates a new ACL rule, and returns the corresponding ACL entry in the response. The returned entry includes several new elements or properties provided by the server.
If there is already a rule in the access control list with a scope whose type and value match that in the request, and whose role is anything other than none, then the POST operation fails with error code 409 Conflict.Thats why, try-catch block is used to skip conflict problem.
Now, you can see the calendar is shared with the person whose email_id is given to the scope’s value attribute.
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