Ensure that a selection exists before attempting to execCommand

[BoardJames]

In normal TinyMCE the table toolbar is not shown unless a table is selected. For the table block we want to always show the toolbar even when the editor does not have a table selected so we have to check if a selection is present and supply a default selection when one is not available.

• Fixes Table block causes errors when no table elements are selected #1751
• Fixes Regression: placeholder remains visible after typing #1795
• Closes Prevent TinyMCE table block from breaking placeholders in other blocks #1798
• Fixes Table block: row/column controls don't do anything if a table cell isn't previously focused #2077

[codecov]

Codecov Report

Merging #2143 into master will decrease coverage by 0.02%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #2143      +/-   ##
==========================================
- Coverage   24.23%   24.21%   -0.03%     
==========================================
  Files         142      142              
  Lines        4460     4465       +5     
  Branches      756      758       +2     
==========================================
  Hits         1081     1081              
- Misses       2854     2857       +3     
- Partials      525      527       +2

Impacted Files	Coverage Δ
blocks/library/table/table-block.js	8% <0%> (-2%)	⬇️

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[aduth]

Do we know in this case that the table ancestor here is from this table block, and not another table on the page?

[BoardJames]

Good point. DomUtils.getParent can take a root node as the third parameter so I'll set it to the editor container.

[BoardJames]

Turned out that it needed to be the parent of the editor body otherwise it would not consider the table. Otherwise I think this issue is fixed.

[nylen]

Thanks for the fix. It works well for me.

I added the table back to the demo content (#1806).

This PR should close a few other issues; I've edited them into the original post. Let's wait until after today's release to merge it though, so we get some testing ahead of a release.