commit 7e8884b6db05142e2a585a1bd593676dc19dcfc9
author plainheart <yhen@all-my-life.cn> Tue Jul 13 10:21:46 2021 +0800
committer plainheart <yhen@all-my-life.cn> Tue Jul 13 10:24:54 2021 +0800
tree d55e5dfe9390ad9e0e68135d45dffd42c9d2ce0b
parent edc4367c8da2c8e2189971c470912ffdd62cb0ca

fix(tooltip): should clear the DOM content if user-specified content is null, resolves #14832.

Related previous commit: https://github.com/apache/echarts/pull/12947/commits/3ddb125af1870c233b5d3d8c345bdd17015851eb

src/component/tooltip/TooltipHTMLContent.ts

diff --git a/src/component/tooltip/TooltipHTMLContent.ts b/src/component/tooltip/TooltipHTMLContent.ts
index 73b5b2b..a1e2ac9 100644
--- a/src/component/tooltip/TooltipHTMLContent.ts
+++ b/src/component/tooltip/TooltipHTMLContent.ts
@@ -403,7 +403,10 @@
         borderColor?: ZRColor,
         arrowPosition?: TooltipOption['position']
     ) {
+        const el = this.el;
+
         if (content == null) {
+            el.innerHTML = '';
             return;
         }
 
@@ -412,7 +415,6 @@
             && !shouldTooltipConfine(tooltipModel)) {
             arrow = assembleArrow(tooltipModel.get('backgroundColor'), borderColor, arrowPosition);
         }
-        const el = this.el;
         if (isString(content)) {
             el.innerHTML = content + arrow;
         }