Accessing Tasks from Community Portal with out ownership

Hi,

We had a requirement to update task from community portal.But tasks are not visible to Community portal if he is not owner of that task.

So if we want to do some update on such type of task from Community Portal we have to update a field "IsVisibleInSelfService" on Task to true.

Task taskObj = new Task(id='00Tsdfadere324',IsVisibleInSelfService=true);
update taskObj;

We can update this from Workflow rule also. But in the field Update it will be with the name "Public".

The Field "IsVisibleInSelfService" Indicates whether a task associated with an object can be viewed in the Customer Portal (true) or not (false).

If your organization has enabled Communities, tasks marked IsVisibleInSelfService are visible to any external user in the community, as long as the user has access to the record the task was created on.
This field is available when Customer Portal or partner portal are enabled OR Communities is enabled and you have Customer Portal or partner portal licenses.

Reference:https://www.salesforce.com/developer/docs/api/Content/sforce_api_objects_task.htm