Merge pull request #617 from dataease/pr@dev@feat_map

frontend/src/views/chart/chart/map/map.js

@@ -33,6 +33,7 @@ export function baseMapOption(chart_option, chart) {
       }
       // visualMap
       const valueArr = chart.data.series[0].data
+      if (valueArr && valueArr.length > 0) {
         const values = []
         valueArr.forEach(function(ele) {
           values.push(ele.value)
@@ -42,7 +43,11 @@ export function baseMapOption(chart_option, chart) {
         if (chart_option.visualMap.min === chart_option.visualMap.max) {
           chart_option.visualMap.min = 0
         }
-
+      } else {
+        chart_option.visualMap.min = 0
+        chart_option.visualMap.max = 0
+      }
+      // color
       if (customAttr.color && customAttr.color.colors) {
         chart_option.visualMap.inRange.color = customAttr.color.colors
         chart_option.visualMap.inRange.colorAlpha = customAttr.color.alpha / 100