24 lines
1.5 KiB
Markdown
24 lines
1.5 KiB
Markdown
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# :core:navigation
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## package app.pachli.core.navigation
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Intents for starting activities to break circular dependencies.
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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.
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E.g., if A wants to start B, B provides the method that returns the intent.
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This introduces a dependency between A and B.
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This is worse if B also wants to start A.
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For example, if A is `StatusListActivity` and B is`ViewThreadActivity`. The user might click a status in `StatusListActivity` 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 `StatusListActivity` and `ViewThreadActivity` have a circular dependency.
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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.
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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.
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If the activity's intent requires specific extras those are passed via the constructor, with companion object methods to extract them from the intent.
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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.
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