CODEWITHSUNDEEP
javascript
user1177440
user1177440

Reputation:

JavaScript - Performing a recursive search, value not being retained

I am trying to perform a search on an array of vehicles to see if any match the "Make" of "BMW".

Problem: While matches are found and result is given the value true, that value is lost as the function continues the loop. I thought I would be able to break out of the function, anytime a true value is found. The break is not working.

If I cannot break out of the function and must continue looping thru the remainder of that parent node's properties, how can I retain the true value, as once true is found, I am basically done with this node (vehicle).

Thanks

Here is a truncated look at my node tree:

[
  {
    "title": "2008 BMW 650",
    "price": "30,995.00",
    "type": "Coupes",
    "details" : [{.....}],
    "features" : [
                  { ..... },
                  { "name": "Make", "value": "BMW" },
                  { ..... }
                 ]
  },
  { ..... }
]

let isPresent  = recursiveFilterSearch(node, "Make", "BMW")


function recursiveFilterSearch(node, filterObj, filterValue) {
  let result;

  for (var key in node) {

    // if the any node name & value matches, return true (on this vehicle)

    if (node.name !== undefined) {
      if (node.name === filterObj && node.value === filterValue) {
        result = true;
        break; // <-- not doing what I thought it would do
      }
    }

    // if this node property is an array recursively loop thru the array's properties

    if (result !== true && Object.prototype.hasOwnProperty.call(node, key)) {
      var isArray = Object.prototype.toString.call(node[key]) === '[object Array]';
      if (isArray) {
        var childrenNode = node[key];
        childrenNode.map(function (childNode) {
          recursiveFilterSearch(childNode, filterObj, filterValue);
        });
      }
    }
  }
  return result;
}

Upvotes: 0

Views: 44

Answers (2)

R. Oosterholt
R. Oosterholt

Reputation: 8080

You do not assign the return value of your recursive call:

if (result !== true && Object.prototype.hasOwnProperty.call(node, key)) { 
    var isArray = Object.prototype.toString.call(node[key]) === '[object Array]'; 
    if (isArray) {
        var childrenNode = node[key];             
        childrenNode.map(function (childNode) {
            // assign recursive result
            result = recursiveFilterSearch(childNode, filterObj, filterValue);
        }); 
    }
}

As a side note: Such a generic search functionality will work but if you are developing new functionality and you have full control over the json structure keep things like 'searchability' in mind. Were the structure like:

{
    features: {
        make: "Opel",
        ft2: ""
    }
}

You could loop all object and search like:

if (car.features.make == "Opel") {
    // found in one liner
}

Upvotes: 0

user1177440
user1177440

Reputation:

Struggled hard on this one, no help from those far smarter than I.

I hope this helps others.

I purposely did not do a search by features (as plalx above suggested), because I want to re-use this code on products that may not have a feature section. One can use this for any product, ie. from cars to shoes to TVs. The property names do not matter.

Make note I purposely lower-cased the respective variables, just to play it safe, as well as using indexOf on the value as my client has such values as "Automatic" & "6-speed Automatic", so index will pick up both when a search is done on "automatic".

collection-filter.js (javascript file) 

function recursiveFilterSearch(node, filterObj, filterValue) {
  let result = false;
  for (const prop in node) {
    if (node !== undefined) {
      if (node.value !== undefined) {
        node.name = (node.name).toLowerCase();
        node.value = (node.value).toLowerCase();
        if (node.name === filterObj && (node.value).indexOf(filterValue) > -1) {
          result = true;
        }
      }
      if (typeof(node[prop]) === 'object') {
          recursiveFilterSearch(node[prop], filterObj, filterValue);
      }
      if (result) {
        break;
      }
    }
  }
  return result;
}

module.exports = {
  filterCollection(coll2Filter, filterName, filterValue) {
    const results = [];
    coll2Filter.map((node) => {
      const isMatch = (recursiveFilterSearch(node, filterName.toLowerCase(), filterValue.toLowerCase()));
      if (isMatch) {
        results.push(node);
      }
    });
    return results;
  }
};
}

Inventory.js: (React.js file using alt flux)

import CollectionFilter from '../../components/forms/helpers/collection-filter.js';

  render() {
    if (!this.props.items) return <div>Loading ...</div>;
    const products = this.props.items;
    const result = CollectionFilter.filterCollection(products, 'Trans', 'Automatic');
  return (
   <div>{ result }</div>
  )
  .....

Upvotes: 1

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