support multi sheet selected

example/example.js

@@ -2,7 +2,8 @@ var am_xlsx2json = require('../')
 
 am_xlsx2json({
   input: __dirname + '/place-sample.xls',
-  output: __dirname + '/output.json'
+  output: __dirname + '/output.json',
+  sheet:['Worksheet','Sheet1']
 }, function(err, result) {
   if(err) {
     console.error(err);

lib/index.js

@@ -23,7 +23,7 @@ function XLSX_json(config, callback) {
 
 function CV(config, callback) {
     var wb = this.load_xlsx(config.input)
-    var json = this.to_json(wb);
+    var json = this.to_json(wb,config);
     var output = config.output;
     if (config.output !== null) {
         var stream = fs.createWriteStream(output, {
@@ -39,13 +39,24 @@ function CV(config, callback) {
 CV.prototype.load_xlsx = function(input) {
     return xlsx.readFile(input);
 }
-CV.prototype.to_json = function(workbook) {
+CV.prototype.to_json = function(workbook,config) {
     var result = {};
-    workbook.SheetNames.forEach(function(sheetName) {
-        var roa = xlsx.utils.sheet_to_row_object_array(workbook.Sheets[sheetName]);
-        if(roa.length > 0){
-            result[sheetName] = roa;
-        }
-    });
+    var target_sheet = config.sheet;
+    if (target_sheet == null){
+        workbook.SheetNames.forEach(function(sheetName) {
+            var roa = xlsx.utils.sheet_to_row_object_array(workbook.Sheets[sheetName]);
+            if(roa.length > 0){
+                result[sheetName] = roa;
+            }
+        });
+    } else {
+        target_sheet.forEach(function(sheetName) {
+                var roa = xlsx.utils.sheet_to_row_object_array(workbook.Sheets[sheetName]);
+                    if(roa.length > 0){
+                        result[sheetName] = roa;
+                    }
+        })
+
+    }
     return result;
 }
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