From 68e5dbc523dd1f119230650e6096bd946f6e4807 Mon Sep 17 00:00:00 2001
From: Aman Harwara <amanharwara@protonmail.com>
Date: Wed, 18 Oct 2023 22:11:30 +0530
Subject: [PATCH] chore: add table markdown transformer to super

---
 .../SuperEditor/MarkdownTransformers.ts       | 166 +++++++++++++++++-
 1 file changed, 164 insertions(+), 2 deletions(-)

diff --git a/packages/web/src/javascripts/Components/SuperEditor/MarkdownTransformers.ts b/packages/web/src/javascripts/Components/SuperEditor/MarkdownTransformers.ts
index 66d10e698..0d3d4c0ba 100644
--- a/packages/web/src/javascripts/Components/SuperEditor/MarkdownTransformers.ts
+++ b/packages/web/src/javascripts/Components/SuperEditor/MarkdownTransformers.ts
@@ -5,14 +5,27 @@ import {
   TEXT_FORMAT_TRANSFORMERS,
   TEXT_MATCH_TRANSFORMERS,
   TextMatchTransformer,
+  $convertToMarkdownString,
+  $convertFromMarkdownString,
 } from '@lexical/markdown'
-
+import {
+  $createTableCellNode,
+  $createTableNode,
+  $createTableRowNode,
+  $isTableCellNode,
+  $isTableNode,
+  $isTableRowNode,
+  TableCellHeaderStates,
+  TableCellNode,
+  TableNode,
+  TableRowNode,
+} from '@lexical/table'
 import {
   HorizontalRuleNode,
   $createHorizontalRuleNode,
   $isHorizontalRuleNode,
 } from '@lexical/react/LexicalHorizontalRuleNode'
-import { LexicalNode } from 'lexical'
+import { $isParagraphNode, $isTextNode, LexicalNode } from 'lexical'
 import {
   $createRemoteImageNode,
   $isRemoteImageNode,
@@ -59,7 +72,156 @@ const IMAGE: TextMatchTransformer = {
   type: 'text-match',
 }
 
+// Table transformer, taken from Lexical Playground
+const TABLE_ROW_REG_EXP = /^(?:\|)(.+)(?:\|)\s?$/
+const TABLE_ROW_DIVIDER_REG_EXP = /^(\| ?:?-*:? ?)+\|\s?$/
+
+function getTableColumnsSize(table: TableNode) {
+  const row = table.getFirstChild()
+  return $isTableRowNode(row) ? row.getChildrenSize() : 0
+}
+
+function createTableCell(textContent: string): TableCellNode {
+  textContent = textContent.replace(/\\n/g, '\n')
+  const cell = $createTableCellNode(TableCellHeaderStates.NO_STATUS)
+  $convertFromMarkdownString(textContent, MarkdownTransformers, cell)
+  return cell
+}
+
+function mapToTableCells(textContent: string): Array<TableCellNode> | null {
+  const match = textContent.match(TABLE_ROW_REG_EXP)
+  if (!match || !match[1]) {
+    return null
+  }
+  return match[1].split('|').map((text) => createTableCell(text))
+}
+
+export const TABLE: ElementTransformer = {
+  dependencies: [TableNode, TableRowNode, TableCellNode],
+  export: (node: LexicalNode) => {
+    if (!$isTableNode(node)) {
+      return null
+    }
+
+    const output: string[] = []
+
+    for (const row of node.getChildren()) {
+      const rowOutput = []
+      if (!$isTableRowNode(row)) {
+        continue
+      }
+
+      let isHeaderRow = false
+      for (const cell of row.getChildren()) {
+        // It's TableCellNode so it's just to make flow happy
+        if ($isTableCellNode(cell)) {
+          rowOutput.push($convertToMarkdownString(MarkdownTransformers, cell).replace(/\n/g, '\\n'))
+          if (cell.__headerState === TableCellHeaderStates.ROW) {
+            isHeaderRow = true
+          }
+        }
+      }
+
+      output.push(`| ${rowOutput.join(' | ')} |`)
+      if (isHeaderRow) {
+        output.push(`| ${rowOutput.map((_) => '---').join(' | ')} |`)
+      }
+    }
+
+    return output.join('\n')
+  },
+  regExp: TABLE_ROW_REG_EXP,
+  replace: (parentNode, _1, match) => {
+    // Header row
+    if (TABLE_ROW_DIVIDER_REG_EXP.test(match[0])) {
+      const table = parentNode.getPreviousSibling()
+      if (!table || !$isTableNode(table)) {
+        return
+      }
+
+      const rows = table.getChildren()
+      const lastRow = rows[rows.length - 1]
+      if (!lastRow || !$isTableRowNode(lastRow)) {
+        return
+      }
+
+      // Add header state to row cells
+      lastRow.getChildren().forEach((cell) => {
+        if (!$isTableCellNode(cell)) {
+          return
+        }
+        cell.toggleHeaderStyle(TableCellHeaderStates.ROW)
+      })
+
+      // Remove line
+      parentNode.remove()
+      return
+    }
+
+    const matchCells = mapToTableCells(match[0])
+
+    if (matchCells == null) {
+      return
+    }
+
+    const rows = [matchCells]
+    let sibling = parentNode.getPreviousSibling()
+    let maxCells = matchCells.length
+
+    while (sibling) {
+      if (!$isParagraphNode(sibling)) {
+        break
+      }
+
+      if (sibling.getChildrenSize() !== 1) {
+        break
+      }
+
+      const firstChild = sibling.getFirstChild()
+
+      if (!$isTextNode(firstChild)) {
+        break
+      }
+
+      const cells = mapToTableCells(firstChild.getTextContent())
+
+      if (cells == null) {
+        break
+      }
+
+      maxCells = Math.max(maxCells, cells.length)
+      rows.unshift(cells)
+      const previousSibling = sibling.getPreviousSibling()
+      sibling.remove()
+      sibling = previousSibling
+    }
+
+    const table = $createTableNode()
+
+    for (const cells of rows) {
+      const tableRow = $createTableRowNode()
+      table.append(tableRow)
+
+      for (let i = 0; i < maxCells; i++) {
+        tableRow.append(i < cells.length ? cells[i] : createTableCell(''))
+      }
+    }
+
+    const previousSibling = parentNode.getPreviousSibling()
+    if ($isTableNode(previousSibling) && getTableColumnsSize(previousSibling) === maxCells) {
+      previousSibling.append(...table.getChildren())
+      parentNode.remove()
+    } else {
+      parentNode.replace(table)
+    }
+
+    table.selectEnd()
+  },
+  type: 'element',
+}
+
 export const MarkdownTransformers = [
+  TABLE,
   CHECK_LIST,
   IMAGE,
   ...ELEMENT_TRANSFORMERS,