fixed bug with exporting to csv when categories are null

src/modules/Exports.js

@@ -256,6 +256,11 @@ class Exports {
  }
  }
 
+ // let the caller know the current category is null. this can happen for example
+ // when dealing with line charts having inconsistent time series data
+ if (cat === null)
+ return 'nullvalue'
+
  if (Array.isArray(cat)) {
  cat = cat.join(' ')
  }
@@ -282,6 +287,11 @@ class Exports {
  columns = []
 
  let cat = getCat(i)
+
+ // current category is null, let's move on to the next one
+ if (cat === 'nullvalue')
+ continue
+
  if (!cat) {
  if (dataFormat.isFormatXY()) {
  cat = series[sI].data[i].x
@@ -296,8 +306,8 @@ class Exports {
  isTimeStamp(cat)
  ? w.config.chart.toolbar.export.csv.dateFormatter(cat)
  : Utils.isNumber(cat)
- ? cat
- : cat.split(columnDelimiter).join('')
+  ? cat
+  : cat.split(columnDelimiter).join('')
  )
 
  for (let ci = 0; ci < w.globals.series.length; ci++) {
@@ -380,8 +390,8 @@ class Exports {
  isTimeStamp(cat) && w.config.xaxis.type === 'datetime'
  ? w.config.chart.toolbar.export.csv.dateFormatter(cat)
  : Utils.isNumber(cat)
- ? cat
- : cat.split(columnDelimiter).join(''),
+  ? cat
+  : cat.split(columnDelimiter).join(''),
  data[cat].join(columnDelimiter),
  ])
  })
@@ -446,7 +456,7 @@ class Exports {
 
  this.triggerDownload(
  'data:text/csv; charset=utf-8,' +
-  encodeURIComponent(universalBOM + result),
+ encodeURIComponent(universalBOM + result),
  fileName ? fileName : w.config.chart.toolbar.export.csv.filename,
  '.csv'
  )