Update reducedFilter.md

snippets/reducedFilter.md

@@ -1,78 +1,33 @@
 ### reducedFilter
 
-Filter an array of objects based on condition and return array with reduced objects.
+Filter an array of objects based on a condition while also filtering out unspecified keys.
 
-#### Input
-
-* Data: the data to be filtered (array of objects) 
-* Condition: will be used for filtering (string) 
-* outputProps: an array of properties that will be used to contruct new array of objects 
-
-#### Output
-
-* Filtered array with new objects. Properties of new objects are a subset of
-properties of original objects 
-
-#### Info
-
-Used ES6 Array.reduce() in order to filter an array with objects based on condition.
-If condition is met, then Array.reduce is used again to construct object with the predefined properties. Further more, in order to dynamically evaluate condition based in object properties, item must be passed through window to Function constructor. Finally, when new object is constructed then it is saved in the output array. 
+Use `Array.filter()` to filter the array based on the predicate `fn` so that it returns the objects for
+which the condition returned a truthy value. On the filtered array, use `Array.map()` to return the new object using `Array.reduce()` to filter out the keys which were not supplied as the `keys` argument.
 
 ```js
-const safeEval = (condition) => new Function('return '+condition)();
-
-const reducedFilter = (data, condition, outputProps) => 
-    data.reduce( (acc, item) => {
-    window.item = item;
-    if(safeEval(condition)) {
-      const parsedObj = outputProps.reduce( (aggr, index) => {
-        aggr[index] = item[`${index}`];
-        return aggr;
-      }, {});
-      acc[acc.length]=parsedObj; 
-    } 
-    return (acc);
-  }, []);
-  /*
-  Usage example:
-
-  Input data sample is an array of Objects
-
-  const data = [{
-  "id": 1,
-  "first_name": "Jo",
-  "last_name": "Blackstone",
-  "email": "jblackstone0@yahoo.co.jp",
-  "gender": "Male",
-  "ip_address": "255.171.18.115"
-}, ... ]
-
-const condition = `window.item.first_name[0] ==='B'`;
-
-const outputProps = ['first_name','id', 'last_name', 'ip_address'];
-
-const output = reducedFilter(data, condition, outputProps); -->
-
-Output conditionally filtered data sample. Properties of output objects are subset of 
-the properties of the original objects. 
-
-Filtered output data :
-
-[
-Object {
-  first_name: "Bertina",
-  id: 6,
-  ip_address: "33.239.93.222",
-  last_name: "Pinching"
-},
-Object {
-  first_name: "Beckie",
-  id: 13,
-  ip_address: "239.111.225.202",
-  last_name: "Thomesson"
-}, ... ]
-
-
-  */
+const reducedFilter = (data, keys, fn) =>
+  data.filter(fn).map(el =>
+    keys.reduce((acc, key) => {
+      acc[key] = el[key];
+      return acc;
+    }, {})
+  );
 ```
 
+```js
+const data = [
+  {
+    id: 1,
+    name: 'john',
+    age: 24
+  },
+  {
+    id: 2,
+    name: 'mike',
+    age: 50
+  }
+];
+
+reducedFilter(data, ['id', 'name'], item => item.age > 24); // [{ id: 2, name: 'mike'}]
+```