Reproduction: SVG Yield vs Return / Mario Delgado / Observable
Please explain why:
- svg1 is re-rendered when referenced again in a cell
- svg2 is not re-rendered when referenced again in a cell
Not sure why, but if you make an HTML cell it updates the SVG element
${svg2}
In short, when you write a variable in a cell, you’re not just defining or referencing it like in plain linear JavaScript or Python, you are attaching it to the DOM. So when a variable is already attached and you make a cell with it a second time, Observable does not try to reattach the var or duplicate it. It invokes Inspector to show var type and content.
This is a dynamic Observable feature that I don’t think is explained anywhere except in this notebook by @mootari.
Maybe the inspector should also hint at the bottom of its output that “the variable is already attached (here), see (docs)”. That would make this feature more self-discoverable.
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Very helpful discussion in the notebook. It’s share-able and not officially published yet, so I’ve added comments suggesting that @mootari publish it so it will show up in searches.