✨ Add support for retrieving page content in Markdown

Author: Sergei Orlov

README.md

@@ -90,12 +90,16 @@ query {
 	allNotion {
 		edges {
 			node {
+				id
+				parent
+				children
+				internal
 				title
 				properties
-				archived
+				achived
 				createdAt
 				updatedAt
-				children
+				markdown
 				raw
 			}
 		}
@@ -157,6 +161,10 @@ Date of the last page update.
 
 Untouched contents of whatever Notion API returned.
 
+### `markdown` (String)
+
+Markdown contents of the page. Limited by blocks currently supported by Notion API. Unsupported blocks turn into HTML comments specifying that Notion marked this block as non-supported.
+
 ## Current state
 
 - Due to the fact that Notion API only appeared recently, and it is still in beta, some blocks are

gatsby-node.js

@@ -1,4 +1,5 @@
 const { getPages } = require("./src/notion-api/get-pages")
+const { getNotionPageMD } = require("./src/transformers/get-page-md")
 const { getNotionPageProperties } = require("./src/transformers/get-page-properties")
 const { getNotionPageTitle } = require("./src/transformers/get-page-title")
 
@@ -21,6 +22,7 @@ exports.sourceNodes = async (
 			archived: page.archived,
 			createdAt: page.created_time,
 			updatedAt: page.last_edited_time,
+			markdown: getNotionPageMD(page),
 			raw: page,
 			parent: null,
 			children: [],

src/transformers/get-page-md.js

@@ -0,0 +1,62 @@
+const { blockToString } = require("../block-to-string")
+
+const EOL_MD = "\n\n"
+
+exports.getNotionPageMD = (page) =>
+	page.children.reduce((acc, block) => {
+		let childBlocksString = ""
+
+		if (block.has_children) {
+			childBlocksString = "<div notion-nested>"
+				.concat(childBlocksString)
+				.concat(this.getNotionPageMD(block))
+				.concat("</div>")
+				.concat(EOL_MD)
+		}
+
+		if (block.type == "paragraph") {
+			return acc.concat(blockToString(block.paragraph.text)).concat(`\n\n`)
+		}
+
+		if (block.type.startsWith("heading_")) {
+			const headingLevel = Number(block.type.split("_")[1])
+
+			return acc
+				.concat("#".repeat(headingLevel))
+				.concat(" ")
+				.concat(blockToString(block[block.type].text))
+				.concat(EOL_MD)
+		}
+
+		if (block.type == "to_do") {
+			return acc
+				.concat(`- [${block.to_do.checked ? "x" : " "}] `)
+				.concat(blockToString(block.to_do.text))
+				.concat(EOL_MD)
+		}
+
+		if (block.type == "bulleted_list_item") {
+			return acc.concat("* ").concat(blockToString(block.bulleted_list_item.text)).concat(EOL_MD)
+		}
+
+		if (block.type == "numbered_list_item") {
+			return acc.concat("1. ").concat(blockToString(block.numbered_list_item.text)).concat(EOL_MD)
+		}
+
+		if (block.type == "toggle") {
+			return acc
+				.concat("<details><summary>")
+				.concat(blockToString(block.toggle.text))
+				.concat("</summary>")
+				.concat(childBlocksString)
+				.concat("</details>")
+		}
+
+		if (block.type == "unsupported") {
+			return acc
+				.concat(`<!-- Block ${block.id} is not supported by Notion API. Yet. -->`)
+				.concat(EOL_MD)
+		}
+
+		return acc
+	}, "")