🎁 seed inside IFrame

[idanilt]

General description

Right now we assume the seed inside the main thread and the IFrame contain only services.
Some times the entire application will be inside the IFrame, in this case, the service won't find the seed because it sends messages to the top window

example: https://codesandbox.io/s/scalecube-js-tutorial-bwtl7

API

Design description

A clear and concise description of the design proposition.

1. Is it a breaking change (not backward compatible)? no
2. Is it adds a new API? no
3. Is it changes existing API? no
4. Is it removes existing API? no

Changes

Provide a link to a PR or code snippet of old and new API.

Selected solution

Create micro lib for addressable post messages and use it in cluster and transport
Advantages

• Simplify cluster and transport
• Robust
• Support more use cases
• Testable

Downside

• Lot of work

Alternative solutions:

Self & Top

In this approach, we will try sending events on self and top
Advantages

• Simple to implement
• It will work out of the box
  Downside
• Hacky and not working properly

Manual piping

In this approach, we won't assume the seed is in the to and we use a utility to pipe event to the top
Advantages

• Simple to implement

Downside

• the developers need to do something active to make it work
• Break existing applications

Addressing

In this approach, we send messages according to the seed address
Downside

• not simple to implement
• Creating a convention that isn't standard
• The user needs to know how to config it

Behavior

Consideration

We should still support seed on main thread and services on IFrame

• this change will affect cluster-browser and affect only browsers

Current behavior (should be maintained)

Given seed on the main thread
When ServiceA added on IFrame
Then it should connect seed

Desired behavior

Given seed on IFrame
When ServiceA added on IFrame
Then it should connect seed

Test cases

Scenario: seed on the main thread service on IFrame
Scenario: seed on IFrame service on IFrame
Scenario: nested IFrames

RoadMap

• Addressable package (Addressable post messages. #259)
• Cluster (Refactor cluster to use addressable #261)
• Transport (transport browser rewrite #263)

[katzIdo]

LGTM