fix(formula): add mathml output config (#393)

* fix(formula): add mathml output config

* Create rare-guests-double.md

Author: cycleccc

.changeset/rare-guests-double.md

@@ -0,0 +1,5 @@
+---
+"@wangeditor-next/plugin-formula": minor
+---
+
+fix(formula): add mathml output config

packages/plugin-formula/src/module/render-elem.ts

@@ -26,6 +26,7 @@ function renderFormula(elem: SlateElement, children: VNode[] | null, editor: IDo
   const containerVnode = h(
     'div',
     {
+      className: 'w-e-textarea-formula-container',
       props: {
         contentEditable: false, // 不可编辑
       },

packages/plugin-formula/src/register-custom-elem/index.ts

@@ -19,16 +19,6 @@ class WangEditorFormulaCard extends HTMLElement {
     super()
     const shadow = this.attachShadow({ mode: 'open' })
     const document = shadow.ownerDocument
-
-    // 将样式通过 link 标签引入
-    const styleLink = document.createElement('link')
-
-    styleLink.rel = 'stylesheet'
-    styleLink.href = 'https://cdn.jsdelivr.net/npm/[email protected]/dist/katex.min.css'
-    styleLink.integrity = 'sha384-n8MVd4RsNIU0tAv4ct0nTaAbDJwPJzDEaqSD1odI+WdtXRGWt2kTvGFasHpSy3SV'
-    styleLink.crossOrigin = 'anonymous'
-    shadow.appendChild(styleLink)
-
     const span = document.createElement('span')
 
     span.style.display = 'inline-block'
@@ -58,6 +48,7 @@ class WangEditorFormulaCard extends HTMLElement {
   private render(value: string) {
     katex.render(value, this.span, {
       throwOnError: false,
+      output: 'mathml',
     })
   }
 }