Add TaskGroup to help schedule async tasks

[google]

Add TaskGroup to help schedule async tasks

[nikgraf]

I think its useful if I describe our use-case:

We see our Web Application as a standalone client, where client-side models are created even though the requests haven't finished yet. This allows people to already interact with an entity. Sometimes actions depend on each other. For example you only can mark a todo item as done when it has been created on the server.

So far I built a task queue which solve the specific use case of adding/removing collaborators from a ticket. https://github.com/blossom/task-queue-dart

Example Usage:

TaskQueue queue = new TaskQueue();

Future future1 = queue.schedule(addCollaboratorFunction, ['user1-id']);
Future future2 = queue.schedule(removeCollaboratorFunction, ['user1-id']);

Right now I'm thinking about a different design where the received data can affect the parameters of the following tasks. For example when you update a todo you probably need the ID you got from previous request which created the todo.

Hmmmm it's starting to get complicated. Probably I should take a different approach of syncing changes …