[Bug] Tree Component: Inconsistent Parent Node Indeterminate State Behavior

[lanzosuarez]

Discussed in #1457

^{Originally posted by lanzosuarez November 26, 2024}
Hi everyone,
I've noticed an inconsistency with the indeterminate state behavior in the Tree component. The issue manifests differently depending on the selection order:

When selecting a child first:

Parent node remains unchecked, doesn't enter indeterminate state

When selecting parent first, then unselecting a child:

Parent correctly enters indeterminate state

Is this intentional?

Expected Behavior:

The parent node should enter indeterminate state in both scenarios when some (but not all) children are selected, regardless of selection order.

Has anyone encountered this issue or have insights on how to achieve consistent indeterminate state behavior?
Let me know if you need any clarification or additional information about my setup.

Here's my code:

<script setup lang="ts">
import { TreeItem, TreeRoot } from "radix-vue";
import { NRSCheckbox, NRSIcon } from "@/main";

type TreeItemData = {
  title: string;
  icon?: string;
  children?: TreeItemData[];
  value: string;
};

interface Props {
  items: TreeItemData[];
  defaultExpanded?: string[];
}

const props = withDefaults(defineProps<Props>(), {
  defaultExpanded: () => [],
});

const value = defineModel<TreeItemData[]>();

// Watch for value changes (for debugging)
watchEffect(() => {
  if (value.value) {
    console.log(
      "Selected items:",
      value.value.map((item) => item.title)
    );
  }
});
</script>

<template>
  <TreeRoot
    v-model="value"
    v-slot="{ flattenItems }"
    class="nrs-tree"
    :items="items"
    :get-key="(item) => item.title"
    :default-expanded="props.defaultExpanded"
    multiple
    propagate-select
  >
    <slot name="header">
      <h2 class="nrs-tree-header">Directory Structure</h2>
    </slot>

    <TreeItem
      v-for="item in flattenItems"
      :key="item._id"
      v-bind="item.bind"
      v-slot="{ isSelected, isIndeterminate, isExpanded, handleSelect }"
      
      :style="{ '--item-level': `${item.level - 1}` }"
      class="nrs-tree-item"
    >
      <template v-if="item.hasChildren">
        <button @click="item.bind.onToggle">
          <NRSIcon
            class="nrs-tree-toggle-icon"
            :name="!isExpanded ? 'chevron-right' : 'chevron-down'"
          />
        </button>
      </template>
      <button
        tabindex="-1"
        @click="
          () => {
            handleSelect();
          }
        "
        @click.stop
      >
        <NRSCheckbox
          :checked="isSelected"
          :id="item._id"
          :indeterminate="isIndeterminate"
          :text="item.value.title"
        />
      </button>
    </TreeItem>
  </TreeRoot>
</template>
<style lang="scss" scoped>
.nrs-tree {
  list-style-type: none;
  user-select: none;
  width: 14rem;
  background-color: var(--nrs-white);
  border-radius: 0.5rem;
  padding: 0.5rem;
  font-size: 0.875rem;
  font-weight: 500;
}

.nrs-tree-header {
  font-weight: 600;
  font-size: 1rem;
  color: var(--nrs-gray-900);
  padding: 0.5rem;
  margin-top: 0.25rem;
}

.nrs-tree-item {
  display: flex;
  align-items: center;
  padding: 0.25rem 0.5rem;
  margin: 0.125rem 0;
  border-radius: 0.25rem;
  outline: none;
  padding-left: calc(var(--item-level) * 2.375rem);

  .nrs-tree-toggle-icon {
    margin-right: 0.25rem;
  }

  &:focus {
    outline: 1px solid red;
  }

  &[data-selected="true"] {
    background-color: var(--nrs-gray-100);
  }
}

.nrs-tree-icon {
  height: 1rem;
  width: 1rem;
  color: var(--nrs-gray-500);
}

.nrs-tree-content {
  padding-left: 0.5rem;
  color: var(--nrs-gray-900);
}

// Reset button styles
button {
  all: unset;
  cursor: pointer;
  display: flex;
  align-items: center;

  &:focus-visible {
    outline: 2px solid var(--nrs-primary-500);
    outline-offset: -2px;
  }
}
</style>


```</div>

[zernonia]

This is intended behavior. However I think we can implement a bubbleSelect props to allow selecting children will set parent item to indeterminate or checked 😁