Merge pull request #9 from flowxo/add/limit-flatten

Add limit option to getFlattenedFields
flowxo · Feb 28, 2017 · 91eaf76 · 91eaf76
2 parents 804db8e + 5f28e75
commit 91eaf76
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Showing 2 changed files with 48 additions and 1 deletion.
diff --git a/lib/index.js b/lib/index.js
@@ -267,8 +267,9 @@ Utils.getFlattenedFields = function(data, options) {
   options = options || {};
   options.delimiter = options.delimiter || DEFAULT_FLATTENED_DELIMITER;
   options.arrayDelimiter = options.arrayDelimiter || DEFAULT_FLATTENED_ARRAY_DELIMITER;
+  options.limit = options.limit || Infinity;
 
-  var output, addOutput;
+  var output, addOutput, outputCount = 0;
 
   if(options.idx) {
     // Return a hashmap.
@@ -288,6 +289,10 @@ Utils.getFlattenedFields = function(data, options) {
   var flatten = function(o, prevKey, prevLabel, isCollection) {
     var itr = _.isArray(o) ? _.forEach : _.forOwn;
     itr(o, function(val, key) {
+      if (outputCount >= options.limit) {
+        return false;
+      }
+
       // Nest the key
       var delimiter = isCollection ? options.arrayDelimiter : options.delimiter;
       var newKey = prevKey ? prevKey + delimiter + key : key;
@@ -317,6 +322,7 @@ Utils.getFlattenedFields = function(data, options) {
         label: humanize(newLabel),
         value: val
       });
+      ++outputCount;
 
     });
   };

diff --git a/spec/specs.js b/spec/specs.js
@@ -364,6 +364,47 @@ describe('Utils', function() {
       }]);
     });
 
+    it('should return flattened fields and honor the limit option', function() {
+      var data = {
+        some: [
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'},
+          {key: 'value'}
+        ]
+      };
+
+      var actual = Utils.getFlattenedFields(data, {limit: 5});
+      expect(actual).toEqual([{
+        key: 'some_+_key',
+        label: 'Some key',
+        value: undefined
+      }, {
+        key: 'some__0__key',
+        label: 'Some 0 key',
+        value: 'value'
+      }, {
+        key: 'some__1__key',
+        label: 'Some 1 key',
+        value: 'value'
+      }, {
+        key: 'some__2__key',
+        label: 'Some 2 key',
+        value: 'value'
+      }, {
+        key: 'some__3__key',
+        label: 'Some 3 key',
+        value: 'value'
+      }]);
+    });
+
     it('should return flattened fields for an object with a custom delimiter', function() {
       var data = {
         some: {