Description
Is this a regression?
- Yes, this behavior used to work in the previous version
The previous version in which this bug was not present was
No response
Description
We have an application with multiple layer of tabs combined with custom route reuse strategy. Most of the tabs are detached and reattached until the tab is closed.
The active tab is determined from the currently active route on each navigation end event. This way if the application is loaded with a specific url, the appropriate tab is selected.
Consider the following routes:
- /tab1
- /tab2
- /tab2/sub1
- /tab2/sub2
On the /tab2 route, another tab group is present with links to the sub routes (and of course a sub router-outlet as well).
If we load the app with the /tabs2/sub2 route, the components of /tab2 and /tab2/sub2 are loaded, which also means that the tab2's ink is initialized to the second tab in the header.
Now, if we navigate to /tab1, these components are not destroyed, however the tab link active flags are set to false because neither /tab2/sub1 nor /tab2/sub2 is active after the navigation ends.
Then if we navigate back to /tab2/sub2, the components are not reinitialized (because of the reuse strategy). but the active flag is changed for the /tab2/sub2 tab link (because it is now active after navigation end).
Reproduction
StackBlitz link: https://stackblitz.com/edit/stackblitz-starters-nckgfk?file=src%2Ftab-active-tracker.directive.ts
Steps to reproduce:
- Click on Tab 1 -> Tab 1 highlighted [OK]
- Click on Tab 2 -> Tab 2 highlighted [OK], inner tab group loaded [OK]
- Click on Sub-Tab 1 -> upper Sub-Tab 1 highlighted [OK], inner Sub-Tab 1 highlighted [OK]
- Click on Sub-Tab 2 -> upper Sub-Tab 2 highlighted [OK], inner Sub-Tab 2 highlighted [OK]
- Click on Tab 1 -> Tab 1 highlighted [OK]
- Click on Sub-Tab 2 -> Tab 2 highlighted [OK], inner Sub 2 is NOT highlighted [NOK]
Expected Behavior
After the step 6 the ink should be re-initialized even if set to the same value.
Actual Behavior
As you can see, the active status is properly set (font is bold on the inner Sub-Tab 2 header element) but the ink is missing.
However, I think I found the root cause of the problem.
When we navigate from the /tab2/sub2 back to /tab1, neither the /tab2/sub1 nor the /tab2/sub2 routes are active so the selectedIndex is set to -1 and the ink's hide() is called. However, the index just set is not processed until the next ngAfterContentChecked call.
Now, when we navigate back to /tab2/sub2 (which was the last active inner tab) the ink handler thinks that despite the selection index is changed (from -1 ro 1), the selection itself is not changed.
I think that in the hide() function of MatInkBar the this._currentItem should be set to null. Because next time when alignToElement is called, the correspondingItem === currentItem check will be true (but the index was changed from 1 -> -1 -> 1 but it was not processed due to a missing ngAfterContentChecked call)
components/src/material/tabs/ink-bar.ts
Line 40 in 0762d69
Environment
Angular CLI: 17.0.5
Node: 18.18.0
Package Manager: npm 9.8.1
OS: win32 x64
Angular: 17.0.5
... animations, cli, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router
Package Version
---------------------------------------------------------
@angular-devkit/architect 0.1700.5
@angular-devkit/build-angular 17.0.5
@angular-devkit/core 17.0.5
@angular-devkit/schematics 17.0.5
@angular/cdk 17.0.2
@angular/material 17.0.2
@schematics/angular 17.0.5
rxjs 7.8.1
typescript 5.2.2
zone.js 0.14.2