Merge pull request #32 from litixsoft/optional_table_headers_sorting

add option `SORT_HEADER` that allows to sort the auto generated header

Author: mrodrig

README.md

@@ -36,6 +36,7 @@ var converter = require('json-2-csv');
     * `WRAP` - String - Wrap values in the delimiter of choice (e.g. wrap values in quotes). Default: `''`
   * `CHECK_SCHEMA_DIFFERENCES` - Boolean - Should we require all documents to have the same schema? Default: `true`
   * `PREPEND_HEADER` - Boolean - Should the auto-generated header be prepended as the first line in the CSV? Default: `true`
+  * `SORT_HEADER` - Boolean - Should the auto-generated header be sorted? Default: `false`
   * `EOL` - String - End of Line Delimiter. Default: `'\n'`
   * `KEYS` - Array - Specify the keys (as strings) that should be converted. Default: `null`
     * If you have a nested object (ie. {info : {name: 'Mike'}}), then set options.KEYS to ['info.name']

lib/constants.json

@@ -27,6 +27,7 @@
     },
     "EOL" : "\n",
     "PREPEND_HEADER" : true,
+    "SORT_HEADER" : false,
     "PARSE_CSV_NUMBERS" : false,
     "KEYS" : null,
     "CHECK_SCHEMA_DIFFERENCES": true

lib/json-2-csv.js

@@ -47,7 +47,14 @@ var generateHeading = function(data) {
             return Promise.reject(new Error(constants.Errors.json2csv.notSameSchema));
         }
 
-        return Promise.resolve(_.flatten(keys[0]));
+
+        var result = _.flatten(keys[0]);
+
+        if (options.SORT_HEADER) {
+            result.sort();
+        }
+
+        return Promise.resolve(result);
     }
 
     var uniqueKeys = [];
@@ -57,6 +64,10 @@ var generateHeading = function(data) {
         uniqueKeys = _.union(uniqueKeys, _.flatten(keyList));
     });
 
+    if (options.SORT_HEADER) {
+        uniqueKeys.sort();
+    }
+
     return Promise.resolve(uniqueKeys);
 };
 

test/CSV/unQuoted/regularJsonSorted.csv

@@ -0,0 +1,5 @@
+carModel,color,price
+Audi,blue,10000
+BMW,red,15000
+Mercedes,yellow,20000
+Porsche,green,30000

test/testCsvFilesList.json

@@ -9,6 +9,7 @@
       {"key": "nestedQuotes", "file": "test/CSV/unQuoted/nestedQuotes.csv"},
       {"key": "noData", "file": "test/CSV/unQuoted/noData.csv"},
       {"key": "regularJson", "file": "test/CSV/unQuoted/regularJson.csv"},
+      {"key": "regularJsonSorted", "file": "test/CSV/unQuoted/regularJsonSorted.csv"},
       {"key": "singleDoc", "file": "test/CSV/unQuoted/singleDoc.csv"},
       {"key": "differentSchemas", "file": "test/CSV/unQuoted/differentSchemas.csv"}
     ]

test/testJson2Csv.js

@@ -26,6 +26,16 @@ var json2csvTests = function () {
                 });
             });
 
+            it('should convert plain JSON to CSV and sort the header', function(done) {
+                converter.json2csv(jsonTestData.regularJson, function(err, csv) {
+                    if (err) { throw err; }
+                    true.should.equal(_.isEqual(err, null));
+                    csv.should.equal(csvTestData.unQuoted.regularJsonSorted);
+                    csv.split(options.EOL).length.should.equal(6);
+                    done();
+                }, {SORT_HEADER: true});
+            });
+
             it('should parse nested JSON to CSV - 1', function(done) {
                 converter.json2csv(jsonTestData.nestedJson, function(err, csv) {
                     if (err) { throw err; }