[hdom] - iterators disappear after initial render about umbrella HOT 2 CLOSED

Iterators can of course only be consumed once, but they do make sense in many situations also in hdom. It all really depends on how your components are setup/created.

1. This will FAIL after first render:

start(["ul", tx.map((i) => ["li", i], tx.range(5))]);

The reason this fails is because the value passed to start() is the array ["ul", iterator], but then the iterator can only be consumed once... hence in the second frame the ul element will have no more children and so they'll be diffed away.

2. This WORKS:

start(["ul", ...tx.map((i) => ["li", i], tx.range(5))]);

Here the spread operator forces the iterator to be realized before the array is passed to start(), so the array is really now a static piece of data ["ul", ["li", 0], ["li", 1], ....]

3. This WORKS too:

start(()=> ["ul", tx.map((i) => ["li", i], tx.range(5))]);

Here the value passed to start is a function which will be re-executed every single time, so works too...

Hope that clears things up!

from umbrella.

It does! Thanks @postspectacular !

from umbrella.