Filter an array based on dynamic keys in an array of nested objects

Question

I've got an array with nested objects in it. Something like this:

const results = [
    { 
        general: {
            orderID: '5567',
            created: 1548765626101,
            status: 'new'
        },

        company: {
            companyName: 'company x',
            companyEmail: 'info@companyx.com',
            companyContact: 'John Doe'
        },

        customer: {
            customerName: 'Jane Doe',
            customerEmail: 'janedoe@email.com'
        },

        products: [
            {
                productID: 4765756,
                productName: 'Product x',
                productDescription: 'Description for product x'
            },
            {
                productID: 4767839,
                productName: 'Product y',
                productDescription: 'Description for product y'
            }
        ],

        payment: {
            price: 1000,
            method: 'cash'
        }

    },
]

(To keep it a little bit structured I only inserted one result object for this question. But let's say there are 100 elements in the results array.)

A user is able to type in a search term and check/uncheck keys that will include or exclude these keys. The keys are hardcoded in a list.

So for example. A user types in 'jane' and checks customerName and customerEmail as the wanted keys to search. Or a user types in 'x' and checks productName.

How can I dynamically search into these checked keys? I'm already having the selected keys in an array.

So for the first example, I've got ['customerName', 'customerEmail'].

For the second one it's ['productName']

I have used array.filter() before for hardcoded keys but I have no clue on how to filter for these dynamic keys.

Can someone help me out with a breakdown of the different steps? I'm working with es6, without external libraries.

Answer 1

Maybe something like this? Keep in mind that 'searchTerm' is type-sensitive.

Usage : search( results, ['companyName', 'productName'], 'x' );

/**
 *  Returns an array of objects which contains at least one 'searchKey' whose value
 *  matches THE 'searchTerm'.
 */
function search( inp, searchKeys, searchTerm ) {
  let retArray = [];

  function rdp( inp, searchKeys, searchTerm ) {

    if ( Array.isArray(inp) ) {
      if (inp.length > 0) {
        inp.forEach(elem => {
            rdp( elem, searchKeys, searchTerm );
        });
      }
    }
    else {
      Object.keys( inp ).forEach( prop => {
          if ( Array.isArray( inp[ prop ] ) || ( typeof inp[ prop ] == 'object')) {
            rdp( inp[ prop ], searchKeys, searchTerm );
          }
          else {
            searchKeys.forEach( key => {
                if (( prop == key ) &&  //  key match
                    ( prop in inp)) {  //  search term found

                  switch ( typeof inp[prop] ) {
                    case 'string' : if (inp[ prop ].indexOf( searchTerm ) > -1) { retArray.push( inp ); } break;
                    case 'number' : if ( inp[ prop ] === searchTerm ) { retArray.push( inp ); } break;
                  }
                }
            });
          }
      });
    }
  }

  rdp( inp, searchKeys, searchTerm );

  return retArray;

}

Answer 2

You need to iterate over the results array and then deep search each object for matching items. For that you will need to

• get all the key/value pairs
• if value is object, search deeper
• if value is array search each item deeper
• otherwise (value is string or number)
  • if key is in the list of fields to search
  • if value is matched to the query return true
  • otherwise return false

Something along the lines of

const deepSearcher = (fields, query) =>
  function matcher(object) {
    const keys = Object.keys(object);

    return keys.some(key => {
      const value = object[key];
      // handle sub arrays
      if (Array.isArray(value)) return value.some(matcher);
      // handle sub objects
      if (value instanceof Object) return matcher(value);
      // handle testable values
      if (fields.includes(key)) {
        // handle strings
        if (typeof value === "string") return value.includes(query);
        // handle numbers
        return value.toString() === query.toString();
      }
      return false;
    });
  };

This function creates a matcher to be used with the .filter method.

const customerFilter = deepSearcher(['customerName', 'customerEmail'], 'jane')
const found = results.filter(customerFilter);

or you can pass it directly to the .filter

const found = results.filter(deepSearcher(['customerName', 'customerEmail'], 'jane'));

The fields you pass to deepSearcher do not have to belong to the same object. The matcher will test anything for a match (but they have to point to string/numbers for this code to work).

---

Working test cases

const results = [{
  general: {
    orderID: "5567",
    created: 1548765626101,
    status: "new"
  },
  company: {
    companyName: "company x",
    companyEmail: "info@companyx.com",
    companyContact: "John Doe"
  },
  customer: {
    customerName: "Jane Doe",
    customerEmail: "janedoe@email.com"
  },
  products: [{
      productID: 4765756,
      productName: "Product x",
      productDescription: "Description for product x"
    },
    {
      productID: 4767839,
      productName: "Product y",
      productDescription: "Description for product y"
    }
  ],
  payment: {
    price: 1000,
    method: "cash"
  }
}];

const deepSearcher = (fields, query) =>
  function matcher(object) {
    const keys = Object.keys(object);

    return keys.some(key => {
      const value = object[key];
      // handle sub arrays
      if (Array.isArray(value)) return value.some(matcher);
      // handle sub objects
      if (value instanceof Object) return matcher(value);
      // handle testable values
      if (fields.includes(key)) {
        // handle strings
        if (typeof value === "string") return value.includes(query);
        // handle numbers
        return value.toString() === query.toString();
      }
      return false;
    });
  };

const matchingCustomer = results.filter(deepSearcher(["customerName", "customerEmail"], 'jane'));
console.log('results with matching customer:', matchingCustomer.length);

const matchingProduct = results.filter(deepSearcher(["productName"], 'x'));
console.log('results with matching product:', matchingProduct.length);


const matchingPrice = results.filter(deepSearcher(["price"], '1000'));
console.log('results with matching price:', matchingPrice.length);

const nonMatchingPrice = results.filter(deepSearcher(["price"], '500'));
console.log('results with non matching price:', nonMatchingPrice.length);