The SubtreeRetainer class keeps track of a number of pieces of data,
comparing the values of these pieces at every iteration.
This is useful for preventing redraws to relatively static (or huge)
components whose VDOM only depends on very few values, when none of them
have changed.
Example
// Check two callbacks for changes on each update this.subtree = newSubtreeRetainer( () =>this.attrs.post.freshness, () =>this.showing );
// Add more callbacks to be checked for updates this.subtree.check(() =>this.attrs.user.freshness);
// In a component's onbeforeupdate() method: returnthis.subtree.needsRebuild()
The
SubtreeRetainerclass keeps track of a number of pieces of data, comparing the values of these pieces at every iteration.This is useful for preventing redraws to relatively static (or huge) components whose VDOM only depends on very few values, when none of them have changed.
Example
See
https://mithril.js.org/lifecycle-methods.html#onbeforeupdate