feat(tree): enable add at location #4772
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src/textual/widgets/_tree.py
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| insert_index = self.children.index(before) | ||
| except ValueError: | ||
| raise AddNodeError( | ||
| "Request to add before an unknown node that is not a child of this node" |
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Struggled to mentally parse the error message a bit here.
| "Request to add before an unknown node that is not a child of this node" | |
| "The node specified for 'before' does not exist in this Tree." |
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Actually on reading the code in more detail I think my suggestion isn't clear.
Maybe something like f"cannot insert before {before}, as this node only has {len(children)} children"?
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Yes I struggled a bit with how to word this error message!
The node specified for 'before' does not exist in this Tree.
Perhaps I've misunderstood, but this wording suggests the node doesn't exist in the whole Tree which might not be the case? You might just be adding to the wrong node, for example:
from textual.app import App, ComposeResult
from textual.widgets import Tree
class ExampleApp(App):
def compose(self) -> ComposeResult:
tree = Tree[None]("root")
tree.root.expand()
node_1 = tree.root.add("node 1", expand=True)
leaf_1_1 = node_1.add_leaf("node 1.1")
node_2 = tree.root.add("node 2", expand=True)
leaf_2_1 = node_2.add_leaf("node 2.1")
leaf_error = node_2.add("leaf error", after=leaf_1_1)
yield tree
if __name__ == "__main__":
app = ExampleApp()
app.run()There was a problem hiding this comment.
Haha yeah, I realised that after posting. See my other comment 😄
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f"cannot insert before {before}, as this node only has {len(children)} children"
Sorry but I'm not sure that's quite right either. The length of the children isn't relevant, rather that the TreeNode passed as the before isn't a child node of this node?
"The node specified for the before node is not a child of this node" is a bit confusing to try to express clearly!
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ah sorry, i thought we were in the isinstance(before, int) branch 🤦
how about:
| "Request to add before an unknown node that is not a child of this node" | |
| "The node specified for `before` is not a child of this node" |
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Sorry also just to clarify, if the before/after argument is an index that is out of range, this also won't raise an error (the same as Python's insert)
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Ah ok - that seems fine to me (I wasn't aware that's how insert worked)
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Thanks, that wording is much better! Updated in 04ac1ca (sorry I tried adding you as co-author but always forget that second hyphen!)
src/textual/widgets/_tree.py
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| insert_index = self.children.index(after) + 1 | ||
| except ValueError: | ||
| raise AddNodeError( | ||
| "Request to add after an unknown node that is not a child of this node" |
Co-authored by: Darren Burns <[email protected]>
|
Merged the CHANGELOG. Thanks, Tom. I think we're going to squeeze this in to 0.73.0, which I'll release at EOD. |
Add
beforeandafterparameters to theTreeNode.addandTreeNode.add_leafmethods to enable positioning a new node.Closes #4049.
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