enh(NcRichText): render flavored markdown

Signed-off-by: Maksim Sukharev <antreesy.web@gmail.com>

cypress/component/richtext.cy.ts

@@ -228,6 +228,59 @@ describe('NcRichText', () => {
 			})
 		})
 
+		describe('strikethrough text', () => {
+			it('strikethrough text (with single tilda syntax)', () => {
+				mount(NcRichText, {
+					propsData: {
+						text: '~strikethrough single~',
+						useExtendedMarkdown: true,
+					},
+				})
+
+				cy.get('del').should('have.text', 'strikethrough single')
+			})
+
+			it('strikethrough text (with double tilda syntax)', () => {
+				mount(NcRichText, {
+					propsData: {
+						text: '~~strikethrough double~~',
+						useExtendedMarkdown: true,
+					},
+				})
+
+				cy.get('del').should('have.text', 'strikethrough double')
+			})
+
+			it('strikethrough text (several in line with different syntax)', () => {
+				const outputs = ['strikethrough single', 'strikethrough double']
+				mount(NcRichText, {
+					propsData: {
+						text: 'normal text ~strikethrough single~ normal text ~~strikethrough double~~ normal text',
+						useExtendedMarkdown: true,
+					},
+				})
+
+				cy.get('del').should('have.length', 2)
+				cy.get('del').each((item, index) => {
+					expect(item).have.text(outputs[index])
+				})
+			})
+
+			it('strikethrough text (between normal texts with different syntax)', () => {
+				mount(NcRichText, {
+					propsData: {
+						text: 'text~strikethrough~text~~strikethrough~~text',
+						useExtendedMarkdown: true,
+					},
+				})
+
+				cy.get('del').should('have.length', 2)
+				cy.get('del').each((item) => {
+					expect(item).have.text('strikethrough')
+				})
+			})
+		})
+
 		describe('inline code', () => {
 			it('inline code (single with backticks syntax)', () => {
 				mount(NcRichText, {
@@ -515,6 +568,49 @@ describe('NcRichText', () => {
 			})
 		})
 
+		describe('task lists', () => {
+			it('task list (with `- [ ]` and `- [x]` syntax divided with space from text)', () => {
+				const testCases = [
+					{ input: '- [ ] item 1', output: 'item 1', checked: false },
+					{ input: '- [x] item 2', output: 'item 2', checked: true },
+					{ input: '- [ ] item 3', output: 'item 3', checked: false },
+				]
+
+				mount(NcRichText, {
+					propsData: {
+						text: testCases.map(i => i.input).join('\n'),
+						useExtendedMarkdown: true,
+					},
+				})
+
+				cy.get('ul').should('exist')
+				cy.get('li').should('have.length', testCases.length)
+				cy.get('li').each((item, index) => {
+					// Vue 2.7 renders three non-breaking spaces here for some reason
+					expect(item).have.text('   ' + testCases[index].output)
+				})
+				cy.get('input:checked').should('have.length', testCases.filter(test => test.checked).length)
+			})
+		})
+
+		describe('tables', () => {
+			it('table (with `-- | --` syntax)', () => {
+				mount(NcRichText, {
+					propsData: {
+						text: 'Table | Column A | Column B\n-- | -- | --\nRow 1 | Value A1 | Value B1\nRow 2 | Value A2 | Value B2',
+						useExtendedMarkdown: true,
+					},
+				})
+
+				cy.get('table').should('exist')
+				cy.get('thead').should('exist')
+				cy.get('tbody').should('exist')
+				cy.get('tr').should('have.length', 3)
+				cy.get('th').should('have.length', 3)
+				cy.get('td').should('have.length', 6)
+			})
+		})
+
 		describe('dividers', () => {
 			it('dividers (with different syntax)', () => {
 				mount(NcRichText, {

src/components/NcRichText/NcRichText.vue

@@ -79,6 +79,46 @@ textarea {
 </style>
 ```
 
+### Flavored Markdown
+
+This component can support [Github Flavored Markdown](https://github.github.com/gfm/).
+It adds such elements, as tables, task lists, strikethrough, and supports autolinks by default
+
+```vue
+<template>
+	<div>
+		<textarea v-model="text" />
+
+		<NcRichText :text="text" :use-extended-markdown="true"/>
+	</div>
+</template>
+<script>
+	export default {
+		data() {
+			return {
+				text: `## Try flavored markdown right now!
+
+~~strikethrough~~
+
+- [ ] task to be done
+- [x] task completed
+
+Table header | Column A | Column B
+-- | -- | --
+Table row | value A | value B
+`,
+			}
+		},
+	}
+</script>
+<style lang="scss">
+textarea {
+	width: 100%;
+	height: 200px;
+}
+</style>
+```
+
 ### Usage with NcRichContenteditable
 
 See [NcRichContenteditable](#/Components/NcRichContenteditable) documentation for more information
@@ -235,11 +275,13 @@ See [NcRichContenteditable](#/Components/NcRichContenteditable) documentation fo
 
 <script>
 import NcReferenceList from './NcReferenceList.vue'
+import NcCheckboxRadioSwitch from '../NcCheckboxRadioSwitch/NcCheckboxRadioSwitch.vue'
 import { remarkAutolink } from './autolink.js'
 import { remarkPlaceholder, prepareTextNode } from './placeholder.js'
 
 import { unified } from 'unified'
-import markdown from 'remark-parse'
+import remarkParse from 'remark-parse'
+import remarkGfm from 'remark-gfm'
 import breaks from 'remark-breaks'
 import remark2rehype from 'remark-rehype'
 import rehype2react from 'rehype-react'
@@ -298,6 +340,11 @@ export default {
 			type: Boolean,
 			default: false,
 		},
+		/** Provide GitHub Flavored Markdown syntax */
+		useExtendedMarkdown: {
+			type: Boolean,
+			default: false,
+		},
 		autolink: {
 			type: Boolean,
 			default: true,
@@ -338,11 +385,13 @@ export default {
 		},
 		renderMarkdown(h) {
 			const renderedMarkdown = unified()
-				.use(markdown)
+				.use(remarkParse)
 				.use(remarkAutolink, {
 					autolink: this.autolink,
 					useMarkdown: this.useMarkdown,
+					useExtendedMarkdown: this.useExtendedMarkdown,
 				})
+				.use(this.useExtendedMarkdown ? remarkGfm : undefined)
 				.use(breaks)
 				.use(remark2rehype, {
 					handlers: {
@@ -366,6 +415,17 @@ export default {
 						)
 
 						if (!tag.startsWith('#')) {
+							if (this.useExtendedMarkdown) {
+								if (tag === 'li' && Array.isArray(children)
+									&& children[0].tag === 'input'
+									&& children[0].data.attrs.type === 'checkbox') {
+									const [inputNode, , label] = children
+									const inputComponent = h(NcCheckboxRadioSwitch,
+										{ attrs: inputNode.data.attrs },
+										[label])
+									return h(tag, attrs, [inputComponent])
+								}
+							}
 							return h(tag, attrs, children)
 						}
 
@@ -409,7 +469,7 @@ export default {
 		},
 	},
 	render(h) {
-		return this.useMarkdown
+		return this.useMarkdown || this.useExtendedMarkdown
 			? this.renderMarkdown(h)
 			: this.renderPlaintext(h)
 	},

src/components/NcRichText/autolink.js

@@ -23,10 +23,11 @@ const NcLink = {
 	},
 }
 
-export const remarkAutolink = function({ autolink, useMarkdown }) {
+export const remarkAutolink = function({ autolink, useMarkdown, useExtendedMarkdown }) {
 	return function(tree) {
-
-		if (!useMarkdown || !autolink) {
+		// remark-gfm has its own autolink parser which can not be disabled
+		// and thus a local one is not needed
+		if (useExtendedMarkdown || !useMarkdown || !autolink) {
 			return
 		}
 

src/components/NcRichText/richtext.scss

@@ -135,10 +135,10 @@
 
 .rich-text--wrapper-markdown {
 	div > *:first-child,
-	blockquote > *:first-child{
+	blockquote > *:first-child {
 		margin-top: 0 !important;
 	}
-	div > *:last-child ,
+	div > *:last-child,
 	blockquote > *:last-child {
 		margin-bottom: 0 !important;
 	}
@@ -164,6 +164,37 @@
 		list-style-type: disc;
 	}
 
+	ul.contains-task-list {
+		list-style-type: none;
+		padding: 0;
+	}
+
+	table {
+		border-collapse: collapse;
+		border: 2px solid var(--color-border-maxcontrast);
+
+		th,
+		td {
+			padding: var(--default-grid-baseline);
+			border: 1px solid var(--color-border-maxcontrast);
+			&:first-child {
+				border-left: 0;
+			}
+			&:last-child {
+				border-right: 0;
+			}
+		}
+
+		tr {
+			&:first-child th {
+				border-top: 0;
+			}
+			&:last-child td {
+				border-bottom: 0;
+			}
+		}
+	}
+
 	blockquote {
 		padding-left: 13px;
 		border-left: 2px solid var(--color-border-dark);