What Exactly Is an Insertion Marker Block?

[Amber B]

I just updated our local Blockly branch from the master branch after a few months, and I noticed a lot of new references to something called insertion marker blocks. I checked the API documentation online, but all it says is that setInsertionMarker controls whether a block is an insertion marker block or not, not what it is. I googled around to see what an insertion marker block was, but couldn't find anything. What exactly does this new feature do?

[Abby Schmiedt]

Hi Amber, 

If you pick up a block and drag it around insertion markers display a grayed-out block where the block would end up if you dropped it at that point. To see more go here: https://rachel-fenichel.github.io/blockly/tests/playground.html and try connecting any of the blocks. 

We have landed all of the code for insertion markers, but are not going to turn them on yet.  Please see https://github.com/google/blockly/pull/1987#issuecomment-408497702 for more discussion. 

Thanks,

Abby

[Amber B]

Thank you for the explanation!