Components: [Table] When predicate should evaluate on each data emit

[andrewseguin]

The table uses the row when predicate to determine which row template to use for a piece of data, but only once when inserting a new row.

This should be evaluated on each emit to confirm that data objects match to the right row template.

https://stackblitz.com/edit/angular-bgzmrf-tbx3dm?file=app%2Ftable-basic-example.ts

[steve-todorov]

OH MY GOD!!!! I cannot believe I wasted 2 hours debugging this case which turns out to be a bug. Are there any plans to fix this or maybe there's a workaround to the issue which I haven't thought of?

In our case, we have an edit button inside the table row. When clicked, the button calls a function which sets the index of the row being edited and that should in theory open the details row, but in practice doesn't (like with your stackblitz example).

[drakir]

Any progress on this one? As a workaround I re-assign my datasource

[lterfloth]

Would like to know this as well. Currently experiencing that bug

[sl3dg3hamm3r]

Any update on this one? It might be an idea to either let the when - function return a boolean (which is not re-evaluated, as it is implemented right now), or return an observable, which will trigger changes in the table if the observable emits a boolean change, maybe even marked with | async ?

[rhythmnewt]

Is this to be resolved in the upcoming version 8?

[philip-firstorder]

In my case I wanted to implement an infinite scroll, adding new rows at the bottom, but because because of this bug the new rows get broken indexes.

Apart from the missing id="index" attribute I also get the missing class="ng-star-inserted", which means the new rows were ignored my material.

[alexDevBR]

A workaround for this issue is to declare:
@ViewChild(MatTable, {static: false} table: MatTable<any>;

And then use:
this.table.renderRows()
whenever you update the property that when depends on.