Revision history [back]

To extract nodes from a JSON file while keeping a part of the upper level object in line with user input, you can use a combination of techniques such as filtering, mapping, and selecting.

1. Start by reading the JSON file and parsing it into a JavaScript object.

2. Define the user input parameters that will determine which nodes to extract from the JSON file.

3. Use the filter method to select the objects that match the user input criteria.

4. Use the map method to extract the desired nodes and preserve the upper level object by creating a new object with only the necessary properties.

5. Finally, return the extracted nodes in the desired format, such as an array or a new JSON file.

Here is an example code snippet in JavaScript:

// Read the JSON file and parse it
const jsonData = require('./data.json');
const data = JSON.parse(jsonData);

// Define user input
const category = 'books';
const priceThreshold = 10;

// Filter and map nodes
const extractedNodes = data.products.filter((product) => {
  return product.category === category && product.price <= priceThreshold;
}).map((product) => {
  return {
    title: product.title,
    price: product.price,
    category: product.category,
    seller: product.seller
  };
});

// Return results as an array
console.log(extractedNodes);

This code will extract all products that belong to the 'books' category and have a price of $10 or less. The resulting nodes will contain only the desired properties (title, price, category, and seller) while retaining the upper level object's structure.