Sprint Service Enhancement

[DanielQuick]

• [x] Join Sprint
• [x] Leave Sprint
• [x] Create team lead post

[taracell]

Join Sprint and Leave Sprint can be accomplished by adding or subtracting members within the sprint object using Enum Update.addMember, Update.deleteMember when you call the Sprint object, it returns a property labeled members which is a list of strings of members stored as an array in Firebase Firestore.

[taracell]

Examples/use cases: Join/Leave call parameters are Sprint, UpdateSprint enum, String Join button:

_sprint = await _sprintService.update(_sprint, UpdateSprint.addMember, 'member4');

Leave button:

 _sprint = await _sprintService.update(_sprint, UpdateSprint.deleteMember, 'member4');

Please remember that the sprint post are stored as List\<SprintPost> within the Sprint object Create team lead post call parameters are Sprint, SprintPost where a SprintPost object is defined like this:

    SprintPost _post0 = new SprintPost(
        id: \<Define your own and follow it\>
        title: 'Sprint Post 0',
        content: 'Content 0',
        createdAt: DateTime.now().millisecondsSinceEpoch);

Create Post:

_sprint = await _sprintService.updatePost(_sprint, UpdatePost.create,  _post0);

The number 1 below is the index of the list that the sprint post is in. Once you delete a post the next post if any moves up into that space.
Delete Post:

 _sprint = await _sprintService.updatePost(_sprint, UpdatePost.delete, _sprint.posts[1]);

***Since these posts are members of the Sprint Object as a List to update the post get the list index and remove then create a new post from that SprintPost...Use delete then create for update.