8bdbbf4510
This commit introduces 2 new features into DevTools. Directive level dependency inspection: Users can now view which dependencies their directives have injected in the property viewer tab. This view displays not only the dependency but also the resolution path that was used to service the injection. Injector graph inspection: Users can now view a visualization of the element and environment hierarchies in their application. These trees are displayed separately but on the same page in the Injector Tree tab. User can click on individual injectors to view a list of all the providers configured in that injector, as well as highlight the resolution path from that injector to the root (with the corresponding environment injector connection highlighted as well). PR Close #51719 |
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Angular DevTools Communication Protocol
Angular DevTools injects scripts in the user application page that interact with the framework debugging APIs. The injected scripts interact with the extension via message passing using a statically typed protocol.
This subdirectory contains:
- Declaration of a statically typed message bus
- Implementation of priority aware message bus
- Interfaces that declare the messages exchanged between the extension and the page
We use the PriorityAwareMessageBus to ensure that certain messages have higher priority than others. Because of the asynchronous nature of the property exchange there's a risk that a message response may overwrite the result from a more recent response.
An example is:
- We request the state of the component tree
- We update the state
- We request the state of the properties of a particular component
We don't have guarantees that the response of 1. will arrive before the response of 3. Often the response of 1. is larger and might be delivered after 3. In such a case, it may contain the application state prior to the update and override the state update we received from 3.