Create checkbox.ts

Author: ksw2000

lib/checkbox.ts

@@ -0,0 +1,76 @@
+import MarkdownIt from 'markdown-it/lib'
+import Token from 'markdown-it/lib/token'
+
+// modified from https://github.com/mcecot/markdown-it-checkbox
+export function MarkdownItCheckbox(md: MarkdownIt) {
+    let lastId: number = 0
+    function createTokens(checked: boolean, label: string): Token[] {
+        const nodes: Token[] = []
+
+        const id = lastId
+        lastId++
+
+        let token = new Token('checkbox_input', 'input', 0)
+        token.attrs = [['type', 'checkbox'], ['id', id.toString()], ['class', 'task-list-item-checkbox']]
+        if (checked) {
+            token.attrPush(['checked', 'true'])
+        }
+        nodes.push(token)
+
+        token = new Token('label_open', 'label', 1)
+        token.attrs = [['for', id.toString()]]
+        nodes.push(token)
+
+        token = new Token('text', '', 0)
+        token.content = label
+        nodes.push(token)
+
+        nodes.push(new Token('label_close', 'label', -1))
+
+        return nodes
+    }
+
+    function splitTextToken(token: Token): Token[] | null {
+        let matches = token.content.match(/\[(X|\s|\_|\-)\]\s(.*)/i)
+        if (matches === null) {
+            return null
+        }
+
+        let checked = false
+        const value: string = matches[1] || ''
+        const label: string = matches[2] || ''
+        if (value == 'X' || value == 'x') {
+            checked = true
+        }
+        return createTokens(checked, label)
+    }
+
+
+    function checkbox(state: any): void {
+        let blockTokens = state.tokens
+        const l = blockTokens.length
+        let k = -1
+        for (let j = 0; j < l; j++) {
+            //
+            if (blockTokens[j].type === 'list_item_open') {
+                k = j
+            }
+            if (blockTokens[j].type !== 'inline') {
+                continue
+            }
+            let tokens = blockTokens[j].children
+            for (let i = tokens.length - 1; i >= 0; i--) {
+                const newTokens = splitTextToken(tokens[i])
+                if (newTokens !== null) {
+                    tokens = md.utils.arrayReplaceAt(tokens, i, newTokens)
+                    blockTokens[j].children = tokens
+                    if (k !== -1) {
+                        blockTokens[k].attrs = [['class', 'task-list-item']]
+                    }
+                }
+            }
+        }
+    }
+
+    md.core.ruler.push('checkbox', checkbox)
+}