# Group Activities

## Local Properties
| Property    | Description      | Type                 | Constraints | Supported operations |
| :---------: | -------------    | ----                 | ----------- | -------------------- |
| id          | Activity id      | Integer              | x > 0       | READ                 |
| version     | Activity version | Integer              | x > 0       | READ                 |
| comment     |                  | Formattable          |             | READ / WRITE         |
| details     |                  | Array of Formattable |             | READ                 |
| createdAt   | Time of creation | DateTime             |             | READ                 |

Activity can be either _type Activity or _type Activity::Comment.

## Activity [/api/v3/activities/{id}]

+ Model
    + Body

            {
                "_type": "Activity::Comment",
                "_links": {
                    "self": {
                        "href": "/api/v3/activity/1",
                        "title": "Priority changed from High to Low"
                    },
                    "workPackage": {
                        "href": "/api/v3/work_packages/1",
                        "title": "quis numquam qui voluptatum quia praesentium blanditiis nisi"
                    },
                    "user": {
                        "href": "/api/v3/users/1",
                        "title": "John Sheppard - admin"
                    }
                },
                "id": 1,
                "details": [
                    {
                        "format": "textile",
                        "raw": "Lorem ipsum dolor sit amet.",
                        "html": "<p>Lorem ipsum dolor sit amet.</p>"
                    }
                ],
                "comment": {
                    "format": "textile",
                    "raw": "Lorem ipsum dolor sit amet.",
                    "html": "<p>Lorem ipsum dolor sit amet.</p>"
                },
                "createdAt": "2014-05-21T08:51:20Z",
                "version": 31
            }

## View activity [GET]

+ Parameters
    + id (required, integer, `1`) ... Activity id

+ Response 200 (application/hal+json)

    [Activity][]

## Update activity [PATCH]

Updates an activity's comment and, on success, returns the updated activity.

+ Parameters
    + id (required, integer, `1`) ... Activity id

+ Request (application/json)

        {
          "comment": { "raw": "The updated comment" }
        }

+ Response 200 (application/hal+json)

    [Activity][]

+ Response 400 (application/hal+json)

    Occurs when the client did not send a valid JSON object in the request body.

    + Body

            {
                "_type": "Error",
                "errorIdentifier": "urn:openproject-org:api:v3:errors:InvalidRequestBody",
                "message": "The request body was not a single JSON object."
            }

+ Response 403 (application/hal+json)

    Returned if the client does not have sufficient permissions.

    **Required permission:** edit journals

    + Body

            {
                "_type": "Error",
                "errorIdentifier": "urn:openproject-org:api:v3:errors:MissingPermission",
                "message": "You are not allowed to edit the comment of this journal entry."
            }


+ Response 422 (application/hal+json)

    Returned if the client tries to modify a read-only property.

    + Body

            {
                "_type": "Error",
                "errorIdentifier": "urn:openproject-org:api:v3:errors:PropertyIsReadOnly",
                "message": "The ID of an activity can't be changed."
            }