Modifying treeData in state does not trigger an onChange or other event. about react-sortable-tree HOT 5 CLOSED

Hm.. I designed it so that it would update to reflect any changes in the state, without having to explicitly trigger anything. Are you modifying the object in-place?
e.g.,

this.state.myTree[3].bar = "foo";
this.setState({ myTree: this.state.myTree });

Every data operation I did in the library (and in the tree data APIs) did something more like

const index = 3;
this.setState({ myTree: [
    ...this.state.myTree.slice(0, index),
    { ...this.state.myTree[index], bar: "foo" },
    ...this.state.myTree.slice(index + 1),
] });

I forget, but I think that's called a pure function, or treating objects as immutable.

If this doesn't help, do you mind posting the relevant parts of your code?

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Thanks for the expedient reply. Revised what I posted prior. Did it your way, worked. Still grokking why and immutability... :)

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Glad to hear!
More so than my library, I think it might have something to do with how React detects changes in state. Assigning new values to an object without recreating it makes it so the previous reference is unchanged, and objects are passed around by reference (I think).

Here's a little proof-of-concept from the terminal:

$ node
> a = {b: 1}
{ b: 1 }
> c = a
{ b: 1 }
> c.b = 2
2
> a === c
true

from react-sortable-tree.

Hi,
How do we get index?
Can we use treeIndex to modify the tree node title?

Actually I just wanted to change the title of any node. Please suggest me how to achieve this.

@fritz-c can you please look into it. How do I update any tree node title by uisng the treeIndex for path?

Thanks

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So I should be able to use the functions like addNodeUnderParent when hosting this in a PureComponent with no issue?

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