javascript - Create parent and child relationship using lodash

Javascript - Create parent and child relationship using lodash

To create a parent-child relationship using lodash in JavaScript, you can use the groupBy function. Here's an example:

const _ = require('lodash'); const data = [ { id: 1, name: 'Parent A', parentId: null }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B', parentId: null }, { id: 5, name: 'Child B1', parentId: 4 }, { id: 6, name: 'Child B2', parentId: 4 }, ]; // Group the data by parentId const groupedData = _.groupBy(data, 'parentId'); // Create a function to recursively build the tree structure const buildTree = (parentId) => { const children = groupedData[parentId] || []; return children.map(child => ({ ...child, children: buildTree(child.id) })); }; // Build the tree starting from null (top-level parents) const tree = buildTree(null); console.log(JSON.stringify(tree, null, 2));

In this example:

  • The groupBy function from lodash is used to group the data by the parentId.
  • The buildTree function is defined to recursively build the tree structure.
  • The tree is constructed by calling buildTree(null) to start from the top-level parents.

The resulting tree will be a hierarchical structure representing the parent-child relationship. Adjust the structure of your data and the logic inside the buildTree function based on your specific use case.

Examples

  1. JavaScript code to create a parent-child relationship using lodash for flat data

    const flatData = [ { id: 1, name: 'Parent A' }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B' }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const groupedData = _.groupBy(flatData, 'parentId'); const treeData = groupedData[undefined].map(parent => ({ ...parent, children: groupedData[parent.id] || [] })); console.log(treeData);

    Description: This code uses lodash's groupBy function to group flat data by parentId and then creates a parent-child relationship for a tree structure.

  2. JavaScript code to create nested parent-child relationships using lodash

    const flatData = [ { id: 1, name: 'Parent A' }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B' }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const treeData = _.transform(flatData, (result, item) => { const parent = _.find(result, { id: item.parentId }); if (parent) { (parent.children || (parent.children = [])).push(item); } else { result.push({ ...item, children: [] }); } }, []); console.log(treeData);

    Description: This code uses lodash's transform function to create nested parent-child relationships for a tree structure.

  3. JavaScript code to create a tree structure with lodash and specific child key

    const flatData = [ { id: 1, name: 'Parent A' }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B' }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const treeData = _.reduce(flatData, (result, item) => { const parent = _.find(result, { id: item.parentId }); const newItem = { ...item, children: [] }; if (parent) { parent.children.push(newItem); } else { result.push(newItem); } return result; }, []); console.log(treeData);

    Description: This code uses lodash's reduce function to create a tree structure with a specific child key.

  4. JavaScript code to create a tree structure with lodash and custom id and parent id keys

    const flatData = [ { customId: 1, label: 'Parent A', customParentId: null }, { customId: 2, label: 'Child A1', customParentId: 1 }, { customId: 3, label: 'Child A2', customParentId: 1 }, { customId: 4, label: 'Parent B', customParentId: null }, { customId: 5, label: 'Child B1', customParentId: 4 }, ]; const treeData = _.reduce(flatData, (result, item) => { const parent = _.find(result, { customId: item.customParentId }); const newItem = { ...item, children: [] }; if (parent) { parent.children.push(newItem); } else { result.push(newItem); } return result; }, []); console.log(treeData);

    Description: This code uses lodash's reduce function to create a tree structure with custom id and parent id keys.

  5. JavaScript code to create a hierarchical structure using lodash and a recursive function

    const flatData = [ { id: 1, name: 'Parent A', parentId: null }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B', parentId: null }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const buildHierarchy = (items, parentId = null) => _.filter(items, { parentId }) .map(item => ({ ...item, children: buildHierarchy(items, item.id) })); const treeData = buildHierarchy(flatData); console.log(treeData);

    Description: This code uses a recursive function and lodash's filter to create a hierarchical structure.

  6. JavaScript code to create a tree structure with lodash and a mapping object

    const flatData = [ { id: 1, name: 'Parent A', parentId: null }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B', parentId: null }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const mapping = _.keyBy(flatData, 'id'); const treeData = _.transform(flatData, (result, item) => { if (item.parentId === null) { result.push({ ...item, children: [] }); } else { const parent = mapping[item.parentId]; (parent.children || (parent.children = [])).push(item); } }, []); console.log(treeData);

    Description: This code uses lodash's keyBy to create a mapping object and transform to create a tree structure.

  7. JavaScript code to create a parent-child relationship with lodash and map values

    const flatData = [ { id: 1, name: 'Parent A' }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B' }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const treeData = _.mapValues(_.groupBy(flatData, 'parentId'), (children, parentId) => parentId === 'undefined' ? children : children.map(child => ({ ...child, children: [] })) ); console.log(treeData.undefined);

    Description: This code uses lodash's groupBy and mapValues to create a parent-child relationship with mapped values.

  8. JavaScript code to create a tree structure using lodash and a flatMap approach

    const flatData = [ { id: 1, name: 'Parent A' }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B' }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const treeData = _.flatMap(flatData, item => item.parentId === null ? { ...item, children: [] } : [] ); console.log(treeData);

    Description: This code uses lodash's flatMap approach to create a tree structure.

  9. JavaScript code to create a tree structure using lodash and a recursive flatMap function

    const flatData = [ { id: 1, name: 'Parent A' }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B' }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const buildTree = (items, parentId = null) => _.flatMap(items, item => (item.parentId === parentId ? [{ ...item, children: buildTree(items, item.id) }] : [])); const treeData = buildTree(flatData); console.log(treeData);

    Description: This code uses a recursive buildTree function with lodash's flatMap to create a tree structure.

  10. JavaScript code to create parent-child relationships with lodash and a Map

    const flatData = [ { id: 1, name: 'Parent A' }, { id: 2, name: 'Child A1', parentId: 1 }, { id: 3, name: 'Child A2', parentId: 1 }, { id: 4, name: 'Parent B' }, { id: 5, name: 'Child B1', parentId: 4 }, ]; const parentMap = new Map(); flatData.forEach(item => { if (!item.parentId) { parentMap.set(item.id, { ...item, children: [] }); } else { const parent = parentMap.get(item.parentId); parent.children.push({ ...item, children: [] }); } }); const treeData = [...parentMap.values()]; console.log(treeData);

    Description: This code uses a Map to efficiently create parent-child relationships and construct a tree structure.

More Tags

kml pass-by-reference jquery-effects flutter-appbar compression satellite-image android-contentprovider pdflatex uigesturerecognizer spiral

More Programming Questions

More Investment Calculators

More Fitness-Health Calculators

More Math Calculators

More Trees & Forestry Calculators