Create a Lint warning to replace <fragment> with FragmentContainerView [139830056]

Fixed

Feature Request

Status Update

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Description

il...@google.com

created issue #1

Aug 21, 2019 11:14PM

Component used: Fragment
Version used: 1.2.0-alpha02

Once FragmentContainerView supports android:name (from

https://issuetracker.google.com/issues/139830628), it would be nice to have a Lint warning that would ask developers to replace the old <fragment> tag with <androidx.fragment.app.FragmentContainerView> in order to get the unified lifecycle.

Comments

jb...@google.com <jb...@google.com> Oct 2, 2019 03:48AM

Reassigned to fr...@google.com.

ap...@google.com <ap...@google.com> #2Oct 3, 2019 04:34PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 4707481aa6e0c03da63c1839694a4251a6788bd8
Author: Matthew Fraschilla <fraschilla@google.com>
Date: Tue Oct 01 13:27:07 2019

Create lint warning for fragment tag

The <fragment> tag has a number of short comings:
- You are not allowed to do FragmenTransactions on that ID later
- The fragments are not available until the layout is inflated

This change introduces a lint check to warn developers that they should replace
the fragment tag with FragmentContainerView

Test: new FragmentTagDetectorTest
Bug: 139830056
Change-Id: I0d27070ac773ea17528a75c99dcea99f2f7e1404

A fragment/fragment-lint/src/main/java/androidx/fragment/lint/FragmentIssueRegistry.kt
A fragment/fragment-lint/src/main/java/androidx/fragment/lint/FragmentTagDetector.kt
A fragment/fragment-lint/src/test/java/androidx/fragment/lint/ApiLintVersionsTest.kt
A fragment/fragment-lint/src/test/java/androidx/fragment/lint/FragmentTagDetectorTest.kt

https://android-review.googlesource.com/1131677

https://goto.google.com/android-sha1/4707481aa6e0c03da63c1839694a4251a6788bd8

il...@google.com <il...@google.com> #3Oct 7, 2019 07:27PM

Marked as fixed.

This Lint rule will ship as part of Fragments 1.2.0-beta01 (there's no additional steps you need to enable this Lint rule, just upgrade the Fragment library).

b9...@gmail.com <b9...@gmail.com> #4Oct 9, 2019 08:20PM

Sorry, what should I do when inflate NavHostFragment via xml? In the document it use <fragment> tag to inflate NavHostFragment.

https://developer.android.com/guide/navigation/navigation-getting-started#add-navhostfragment

il...@google.com <il...@google.com> #5Oct 9, 2019 08:22PM

Replace <fragment> with FragmentContainerView. As per this tweet (

https://twitter.com/ianhlake/status/1182006577261268993), we'll be updating documentation across

d.android.com after this release goes stable.

11...@gmail.com <11...@gmail.com> #6Oct 9, 2019 09:37PM

I've tried this fix and failed; Got it working after replacing `android:name="androidx.navigation.fragment.NavHostFragment"` with my start destination fragments' name.

Is this the intended way of using `FragmentContainerView` with navigation? Or am I confused(as per usu...)?

Thanks,
Jon.

11...@gmail.com <11...@gmail.com> #7Oct 9, 2019 10:08PM

Scratch my comment.

Changing the name attr only "works" for a single fragment activity. Sorry.

I ended up reverting back to <fragment/> for now.

il...@google.com <il...@google.com> #8Oct 9, 2019 10:58PM

We're tracking a bug with FragmentContainerView with parsing attributes not working, something that NavHostFragment in particular requires.

Feel free to star

https://issuetracker.google.com/issues/142421837 to track progress on the fix (and for now just continue to use <fragment> for those cases).

bi...@mail.de <bi...@mail.de> #9Oct 24, 2020 02:56PM

Please only suggest the lint fix if the <fragment> is inside a FrameLayout and/xor is the only child of the parent layout.

In my case I want to inflate a Fragment provided by some lib in my in some nested LinearLayout and the replacement doesn't make sense at all in this case.

il...@google.com <il...@google.com> #10Oct 25, 2020 10:40PM

Re #9 - You should always, always inflate a fragment into a FragmentContainerView. There is no exception where you should continue to use <fragment>. You can, of course, put your FragmentContainerView in any layout you want, LinearLayout or otherwise.