24 lines
1.5 KiB
Markdown
24 lines
1.5 KiB
Markdown
# :core:navigation
|
|
|
|
## package app.pachli.core.navigation
|
|
|
|
Intents for starting activities to break circular dependencies.
|
|
|
|
A common approach for surfacing type-safe (ish) intents to start activities is for the activity-to-be-launched to provide a method in a companion object that returns the relevant intent, possibly taking additional parameters that will be included in the intent as extras.
|
|
|
|
E.g., if A wants to start B, B provides the method that returns the intent.
|
|
|
|
This introduces a dependency between A and B.
|
|
|
|
This is worse if B also wants to start A.
|
|
|
|
For example, if A is `TimelineActivity` and B is`ViewThreadActivity`. The user might click a status in `TimelineActivity` to view the thread, starting `ViewThreadActivity`. But from the thread they might click a hashtag to view the list of statuses with that hashtag. Now `TimelineActivity` and `ViewThreadActivity` have a circular dependency.
|
|
|
|
Even if that doesn't happen the dependency means that any changes to B will trigger a rebuild of A, even if the changes to B are not relevant.
|
|
|
|
This package contains `Intent` subclasses that should be used instead. The `quadrant` plugin is used to generate constants that can be used to launch activities by name instead of by class, breaking the dependency chain.
|
|
|
|
If the activity's intent requires specific extras those are passed via the constructor, with companion object methods to extract them from the intent.
|
|
|
|
Using the intent classes from this package is enforced by a lint `IntentDetector` which will warn if any intents are created using a class literal.
|