fix(table): gracefully handle undefined/null columns

[andrewseguin]

Seeing errors in tables that define their columns after the table's content has been initialized. Column input to row definitions should default to an empty array.

Workaround for issue: Initialize column input as an empty array.

Fixes #6831

[jelbourn]

LGTM

[leibale]

@andrewseguin @jelbourn How can i use this PR now (without waiting for merge)? Thanks

[andrewseguin]

@leibale In the meantime, be sure to initialize your columns to an empty array. This error appears when columns are set to null or undefined when provided to the table.

This will error:

export class MyTable {
  myColumns: string[];
}

To fix, initialize myColumns as an empty array.

export class MyTable {
  myColumns: string[] = [];
}

[leibale]

@andrewseguin I thought your PR resolving my issue (#6980) but it isn't the same issue at all..

[angular-automatic-lock-bot]

This issue has been automatically locked due to inactivity.
Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}