feat: htmlToMarkdown (#968)

conf/lang/en-us.ini

@@ -322,6 +322,7 @@ print_text = Enable Printing
 
 [doc]
 word_to_html = Word to HTML
+html_to_markdown = HTML to Markdown
 modify_doc = Modify Document
 comparison = Comparison
 save_merge = Save Merge

conf/lang/zh-cn.ini

@@ -322,6 +322,7 @@ print_text = 开启打印
 
 [doc]
 word_to_html = Word转笔记
+html_to_markdown = HTML转Markdown
 modify_doc = 修改文档
 comparison = 文档比较
 save_merge = 保存合并

static/js/cherry_markdown.js

@@ -152,6 +152,16 @@ $(function () {
                     })
                 }
             },
+            {
+                noIcon: true,
+                name: 'Htm转Markdown',
+                onclick: ()=>{
+                    let converter = new HtmlToMarkdownConverter();
+                    converter.handleFileSelect(function (response) {
+                        window.editor.insertValue(response);
+                    })
+                }
+            }
         ]
     });
 

static/js/html-to-markdown.js

@@ -0,0 +1,29 @@
+
+class HtmlToMarkdownConverter {
+
+    handleFileSelect(callback, accept = '.html,.htm') {
+        let input = document.createElement('input');
+        input.type = 'file';
+        input.accept = accept;
+        input.onchange = (e)=>{
+            let file = e.target.files[0];
+            if (!file) {
+                return;
+            }
+            let reader = new FileReader();
+            reader.onload = (e)=>{
+                let text = e.target.result;
+                let markdown = this.convertToMarkdown(text);
+                callback(markdown);
+            };
+            reader.readAsText(file);
+        };
+        input.click();
+    }
+
+
+    convertToMarkdown(html) {
+        let turndownService = new TurndownService()
+        return turndownService.turndown(html)
+    }
+}

static/js/markdown.js

@@ -446,9 +446,16 @@ $(function () {
                     layer.msg(messages);
                 }
                 converter.replaceHtmlBase64(response.value).then((html)=>{
-                    insertAndClearToMarkdown(html);
+                    let cm = window.editor.cm;
+                    cm.replaceSelection(html);
                 });
             })
+        } else if (name === 'htmlToMarkdown') {
+            let converter = new HtmlToMarkdownConverter();
+            converter.handleFileSelect(function (response) {
+                let cm = window.editor.cm;
+                cm.replaceSelection(response);
+            })
         } else {
             var action = window.editor.toolbarHandlers[name];
 

static/turndown/turndown.js

@@ -0,0 +1,974 @@
+var TurndownService = (function () {
+    'use strict';
+
+    function extend (destination) {
+        for (var i = 1; i < arguments.length; i++) {
+            var source = arguments[i];
+            for (var key in source) {
+                if (source.hasOwnProperty(key)) destination[key] = source[key];
+            }
+        }
+        return destination
+    }
+
+    function repeat (character, count) {
+        return Array(count + 1).join(character)
+    }
+
+    function trimLeadingNewlines (string) {
+        return string.replace(/^\n*/, '')
+    }
+
+    function trimTrailingNewlines (string) {
+        // avoid match-at-end regexp bottleneck, see #370
+        var indexEnd = string.length;
+        while (indexEnd > 0 && string[indexEnd - 1] === '\n') indexEnd--;
+        return string.substring(0, indexEnd)
+    }
+
+    var blockElements = [
+        'ADDRESS', 'ARTICLE', 'ASIDE', 'AUDIO', 'BLOCKQUOTE', 'BODY', 'CANVAS',
+        'CENTER', 'DD', 'DIR', 'DIV', 'DL', 'DT', 'FIELDSET', 'FIGCAPTION', 'FIGURE',
+        'FOOTER', 'FORM', 'FRAMESET', 'H1', 'H2', 'H3', 'H4', 'H5', 'H6', 'HEADER',
+        'HGROUP', 'HR', 'HTML', 'ISINDEX', 'LI', 'MAIN', 'MENU', 'NAV', 'NOFRAMES',
+        'NOSCRIPT', 'OL', 'OUTPUT', 'P', 'PRE', 'SECTION', 'TABLE', 'TBODY', 'TD',
+        'TFOOT', 'TH', 'THEAD', 'TR', 'UL'
+    ];
+
+    function isBlock (node) {
+        return is(node, blockElements)
+    }
+
+    var voidElements = [
+        'AREA', 'BASE', 'BR', 'COL', 'COMMAND', 'EMBED', 'HR', 'IMG', 'INPUT',
+        'KEYGEN', 'LINK', 'META', 'PARAM', 'SOURCE', 'TRACK', 'WBR'
+    ];
+
+    function isVoid (node) {
+        return is(node, voidElements)
+    }
+
+    function hasVoid (node) {
+        return has(node, voidElements)
+    }
+
+    var meaningfulWhenBlankElements = [
+        'A', 'TABLE', 'THEAD', 'TBODY', 'TFOOT', 'TH', 'TD', 'IFRAME', 'SCRIPT',
+        'AUDIO', 'VIDEO'
+    ];
+
+    function isMeaningfulWhenBlank (node) {
+        return is(node, meaningfulWhenBlankElements)
+    }
+
+    function hasMeaningfulWhenBlank (node) {
+        return has(node, meaningfulWhenBlankElements)
+    }
+
+    function is (node, tagNames) {
+        return tagNames.indexOf(node.nodeName) >= 0
+    }
+
+    function has (node, tagNames) {
+        return (
+            node.getElementsByTagName &&
+            tagNames.some(function (tagName) {
+                return node.getElementsByTagName(tagName).length
+            })
+        )
+    }
+
+    var rules = {};
+
+    rules.paragraph = {
+        filter: 'p',
+
+        replacement: function (content) {
+            return '\n\n' + content + '\n\n'
+        }
+    };
+
+    rules.lineBreak = {
+        filter: 'br',
+
+        replacement: function (content, node, options) {
+            return options.br + '\n'
+        }
+    };
+
+    rules.heading = {
+        filter: ['h1', 'h2', 'h3', 'h4', 'h5', 'h6'],
+
+        replacement: function (content, node, options) {
+            var hLevel = Number(node.nodeName.charAt(1));
+
+            if (options.headingStyle === 'setext' && hLevel < 3) {
+                var underline = repeat((hLevel === 1 ? '=' : '-'), content.length);
+                return (
+                    '\n\n' + content + '\n' + underline + '\n\n'
+                )
+            } else {
+                return '\n\n' + repeat('#', hLevel) + ' ' + content + '\n\n'
+            }
+        }
+    };
+
+    rules.blockquote = {
+        filter: 'blockquote',
+
+        replacement: function (content) {
+            content = content.replace(/^\n+|\n+$/g, '');
+            content = content.replace(/^/gm, '> ');
+            return '\n\n' + content + '\n\n'
+        }
+    };
+
+    rules.list = {
+        filter: ['ul', 'ol'],
+
+        replacement: function (content, node) {
+            var parent = node.parentNode;
+            if (parent.nodeName === 'LI' && parent.lastElementChild === node) {
+                return '\n' + content
+            } else {
+                return '\n\n' + content + '\n\n'
+            }
+        }
+    };
+
+    rules.listItem = {
+        filter: 'li',
+
+        replacement: function (content, node, options) {
+            content = content
+                .replace(/^\n+/, '') // remove leading newlines
+                .replace(/\n+$/, '\n') // replace trailing newlines with just a single one
+                .replace(/\n/gm, '\n    '); // indent
+            var prefix = options.bulletListMarker + '   ';
+            var parent = node.parentNode;
+            if (parent.nodeName === 'OL') {
+                var start = parent.getAttribute('start');
+                var index = Array.prototype.indexOf.call(parent.children, node);
+                prefix = (start ? Number(start) + index : index + 1) + '.  ';
+            }
+            return (
+                prefix + content + (node.nextSibling && !/\n$/.test(content) ? '\n' : '')
+            )
+        }
+    };
+
+    rules.indentedCodeBlock = {
+        filter: function (node, options) {
+            return (
+                options.codeBlockStyle === 'indented' &&
+                node.nodeName === 'PRE' &&
+                node.firstChild &&
+                node.firstChild.nodeName === 'CODE'
+            )
+        },
+
+        replacement: function (content, node, options) {
+            return (
+                '\n\n    ' +
+                node.firstChild.textContent.replace(/\n/g, '\n    ') +
+                '\n\n'
+            )
+        }
+    };
+
+    rules.fencedCodeBlock = {
+        filter: function (node, options) {
+            return (
+                options.codeBlockStyle === 'fenced' &&
+                node.nodeName === 'PRE' &&
+                node.firstChild &&
+                node.firstChild.nodeName === 'CODE'
+            )
+        },
+
+        replacement: function (content, node, options) {
+            var className = node.firstChild.getAttribute('class') || '';
+            var language = (className.match(/language-(\S+)/) || [null, ''])[1];
+            var code = node.firstChild.textContent;
+
+            var fenceChar = options.fence.charAt(0);
+            var fenceSize = 3;
+            var fenceInCodeRegex = new RegExp('^' + fenceChar + '{3,}', 'gm');
+
+            var match;
+            while ((match = fenceInCodeRegex.exec(code))) {
+                if (match[0].length >= fenceSize) {
+                    fenceSize = match[0].length + 1;
+                }
+            }
+
+            var fence = repeat(fenceChar, fenceSize);
+
+            return (
+                '\n\n' + fence + language + '\n' +
+                code.replace(/\n$/, '') +
+                '\n' + fence + '\n\n'
+            )
+        }
+    };
+
+    rules.horizontalRule = {
+        filter: 'hr',
+
+        replacement: function (content, node, options) {
+            return '\n\n' + options.hr + '\n\n'
+        }
+    };
+
+    rules.inlineLink = {
+        filter: function (node, options) {
+            return (
+                options.linkStyle === 'inlined' &&
+                node.nodeName === 'A' &&
+                node.getAttribute('href')
+            )
+        },
+
+        replacement: function (content, node) {
+            var href = node.getAttribute('href');
+            if (href) href = href.replace(/([()])/g, '\\$1');
+            var title = cleanAttribute(node.getAttribute('title'));
+            if (title) title = ' "' + title.replace(/"/g, '\\"') + '"';
+            return '[' + content + '](' + href + title + ')'
+        }
+    };
+
+    rules.referenceLink = {
+        filter: function (node, options) {
+            return (
+                options.linkStyle === 'referenced' &&
+                node.nodeName === 'A' &&
+                node.getAttribute('href')
+            )
+        },
+
+        replacement: function (content, node, options) {
+            var href = node.getAttribute('href');
+            var title = cleanAttribute(node.getAttribute('title'));
+            if (title) title = ' "' + title + '"';
+            var replacement;
+            var reference;
+
+            switch (options.linkReferenceStyle) {
+                case 'collapsed':
+                    replacement = '[' + content + '][]';
+                    reference = '[' + content + ']: ' + href + title;
+                    break
+                case 'shortcut':
+                    replacement = '[' + content + ']';
+                    reference = '[' + content + ']: ' + href + title;
+                    break
+                default:
+                    var id = this.references.length + 1;
+                    replacement = '[' + content + '][' + id + ']';
+                    reference = '[' + id + ']: ' + href + title;
+            }
+
+            this.references.push(reference);
+            return replacement
+        },
+
+        references: [],
+
+        append: function (options) {
+            var references = '';
+            if (this.references.length) {
+                references = '\n\n' + this.references.join('\n') + '\n\n';
+                this.references = []; // Reset references
+            }
+            return references
+        }
+    };
+
+    rules.emphasis = {
+        filter: ['em', 'i'],
+
+        replacement: function (content, node, options) {
+            if (!content.trim()) return ''
+            return options.emDelimiter + content + options.emDelimiter
+        }
+    };
+
+    rules.strong = {
+        filter: ['strong', 'b'],
+
+        replacement: function (content, node, options) {
+            if (!content.trim()) return ''
+            return options.strongDelimiter + content + options.strongDelimiter
+        }
+    };
+
+    rules.code = {
+        filter: function (node) {
+            var hasSiblings = node.previousSibling || node.nextSibling;
+            var isCodeBlock = node.parentNode.nodeName === 'PRE' && !hasSiblings;
+
+            return node.nodeName === 'CODE' && !isCodeBlock
+        },
+
+        replacement: function (content) {
+            if (!content) return ''
+            content = content.replace(/\r?\n|\r/g, ' ');
+
+            var extraSpace = /^`|^ .*?[^ ].* $|`$/.test(content) ? ' ' : '';
+            var delimiter = '`';
+            var matches = content.match(/`+/gm) || [];
+            while (matches.indexOf(delimiter) !== -1) delimiter = delimiter + '`';
+
+            return delimiter + extraSpace + content + extraSpace + delimiter
+        }
+    };
+
+    rules.image = {
+        filter: 'img',
+
+        replacement: function (content, node) {
+            var alt = cleanAttribute(node.getAttribute('alt'));
+            var src = node.getAttribute('src') || '';
+            var title = cleanAttribute(node.getAttribute('title'));
+            var titlePart = title ? ' "' + title + '"' : '';
+            return src ? '![' + alt + ']' + '(' + src + titlePart + ')' : ''
+        }
+    };
+
+    function cleanAttribute (attribute) {
+        return attribute ? attribute.replace(/(\n+\s*)+/g, '\n') : ''
+    }
+
+    /**
+     * Manages a collection of rules used to convert HTML to Markdown
+     */
+
+    function Rules (options) {
+        this.options = options;
+        this._keep = [];
+        this._remove = [];
+
+        this.blankRule = {
+            replacement: options.blankReplacement
+        };
+
+        this.keepReplacement = options.keepReplacement;
+
+        this.defaultRule = {
+            replacement: options.defaultReplacement
+        };
+
+        this.array = [];
+        for (var key in options.rules) this.array.push(options.rules[key]);
+    }
+
+    Rules.prototype = {
+        add: function (key, rule) {
+            this.array.unshift(rule);
+        },
+
+        keep: function (filter) {
+            this._keep.unshift({
+                filter: filter,
+                replacement: this.keepReplacement
+            });
+        },
+
+        remove: function (filter) {
+            this._remove.unshift({
+                filter: filter,
+                replacement: function () {
+                    return ''
+                }
+            });
+        },
+
+        forNode: function (node) {
+            if (node.isBlank) return this.blankRule
+            var rule;
+
+            if ((rule = findRule(this.array, node, this.options))) return rule
+            if ((rule = findRule(this._keep, node, this.options))) return rule
+            if ((rule = findRule(this._remove, node, this.options))) return rule
+
+            return this.defaultRule
+        },
+
+        forEach: function (fn) {
+            for (var i = 0; i < this.array.length; i++) fn(this.array[i], i);
+        }
+    };
+
+    function findRule (rules, node, options) {
+        for (var i = 0; i < rules.length; i++) {
+            var rule = rules[i];
+            if (filterValue(rule, node, options)) return rule
+        }
+        return void 0
+    }
+
+    function filterValue (rule, node, options) {
+        var filter = rule.filter;
+        if (typeof filter === 'string') {
+            if (filter === node.nodeName.toLowerCase()) return true
+        } else if (Array.isArray(filter)) {
+            if (filter.indexOf(node.nodeName.toLowerCase()) > -1) return true
+        } else if (typeof filter === 'function') {
+            if (filter.call(rule, node, options)) return true
+        } else {
+            throw new TypeError('`filter` needs to be a string, array, or function')
+        }
+    }
+
+    /**
+     * The collapseWhitespace function is adapted from collapse-whitespace
+     * by Luc Thevenard.
+     *
+     * The MIT License (MIT)
+     *
+     * Copyright (c) 2014 Luc Thevenard <lucthevenard@gmail.com>
+     *
+     * Permission is hereby granted, free of charge, to any person obtaining a copy
+     * of this software and associated documentation files (the "Software"), to deal
+     * in the Software without restriction, including without limitation the rights
+     * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+     * copies of the Software, and to permit persons to whom the Software is
+     * furnished to do so, subject to the following conditions:
+     *
+     * The above copyright notice and this permission notice shall be included in
+     * all copies or substantial portions of the Software.
+     *
+     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+     * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+     * THE SOFTWARE.
+     */
+
+    /**
+     * collapseWhitespace(options) removes extraneous whitespace from an the given element.
+     *
+     * @param {Object} options
+     */
+    function collapseWhitespace (options) {
+        var element = options.element;
+        var isBlock = options.isBlock;
+        var isVoid = options.isVoid;
+        var isPre = options.isPre || function (node) {
+            return node.nodeName === 'PRE'
+        };
+
+        if (!element.firstChild || isPre(element)) return
+
+        var prevText = null;
+        var keepLeadingWs = false;
+
+        var prev = null;
+        var node = next(prev, element, isPre);
+
+        while (node !== element) {
+            if (node.nodeType === 3 || node.nodeType === 4) { // Node.TEXT_NODE or Node.CDATA_SECTION_NODE
+                var text = node.data.replace(/[ \r\n\t]+/g, ' ');
+
+                if ((!prevText || / $/.test(prevText.data)) &&
+                    !keepLeadingWs && text[0] === ' ') {
+                    text = text.substr(1);
+                }
+
+                // `text` might be empty at this point.
+                if (!text) {
+                    node = remove(node);
+                    continue
+                }
+
+                node.data = text;
+
+                prevText = node;
+            } else if (node.nodeType === 1) { // Node.ELEMENT_NODE
+                if (isBlock(node) || node.nodeName === 'BR') {
+                    if (prevText) {
+                        prevText.data = prevText.data.replace(/ $/, '');
+                    }
+
+                    prevText = null;
+                    keepLeadingWs = false;
+                } else if (isVoid(node) || isPre(node)) {
+                    // Avoid trimming space around non-block, non-BR void elements and inline PRE.
+                    prevText = null;
+                    keepLeadingWs = true;
+                } else if (prevText) {
+                    // Drop protection if set previously.
+                    keepLeadingWs = false;
+                }
+            } else {
+                node = remove(node);
+                continue
+            }
+
+            var nextNode = next(prev, node, isPre);
+            prev = node;
+            node = nextNode;
+        }
+
+        if (prevText) {
+            prevText.data = prevText.data.replace(/ $/, '');
+            if (!prevText.data) {
+                remove(prevText);
+            }
+        }
+    }
+
+    /**
+     * remove(node) removes the given node from the DOM and returns the
+     * next node in the sequence.
+     *
+     * @param {Node} node
+     * @return {Node} node
+     */
+    function remove (node) {
+        var next = node.nextSibling || node.parentNode;
+
+        node.parentNode.removeChild(node);
+
+        return next
+    }
+
+    /**
+     * next(prev, current, isPre) returns the next node in the sequence, given the
+     * current and previous nodes.
+     *
+     * @param {Node} prev
+     * @param {Node} current
+     * @param {Function} isPre
+     * @return {Node}
+     */
+    function next (prev, current, isPre) {
+        if ((prev && prev.parentNode === current) || isPre(current)) {
+            return current.nextSibling || current.parentNode
+        }
+
+        return current.firstChild || current.nextSibling || current.parentNode
+    }
+
+    /*
+     * Set up window for Node.js
+     */
+
+    var root = (typeof window !== 'undefined' ? window : {});
+
+    /*
+     * Parsing HTML strings
+     */
+
+    function canParseHTMLNatively () {
+        var Parser = root.DOMParser;
+        var canParse = false;
+
+        // Adapted from https://gist.github.com/1129031
+        // Firefox/Opera/IE throw errors on unsupported types
+        try {
+            // WebKit returns null on unsupported types
+            if (new Parser().parseFromString('', 'text/html')) {
+                canParse = true;
+            }
+        } catch (e) {}
+
+        return canParse
+    }
+
+    function createHTMLParser () {
+        var Parser = function () {};
+
+        {
+            if (shouldUseActiveX()) {
+                Parser.prototype.parseFromString = function (string) {
+                    var doc = new window.ActiveXObject('htmlfile');
+                    doc.designMode = 'on'; // disable on-page scripts
+                    doc.open();
+                    doc.write(string);
+                    doc.close();
+                    return doc
+                };
+            } else {
+                Parser.prototype.parseFromString = function (string) {
+                    var doc = document.implementation.createHTMLDocument('');
+                    doc.open();
+                    doc.write(string);
+                    doc.close();
+                    return doc
+                };
+            }
+        }
+        return Parser
+    }
+
+    function shouldUseActiveX () {
+        var useActiveX = false;
+        try {
+            document.implementation.createHTMLDocument('').open();
+        } catch (e) {
+            if (root.ActiveXObject) useActiveX = true;
+        }
+        return useActiveX
+    }
+
+    var HTMLParser = canParseHTMLNatively() ? root.DOMParser : createHTMLParser();
+
+    function RootNode (input, options) {
+        var root;
+        if (typeof input === 'string') {
+            var doc = htmlParser().parseFromString(
+                // DOM parsers arrange elements in the <head> and <body>.
+                // Wrapping in a custom element ensures elements are reliably arranged in
+                // a single element.
+                '<x-turndown id="turndown-root">' + input + '</x-turndown>',
+                'text/html'
+            );
+            root = doc.getElementById('turndown-root');
+        } else {
+            root = input.cloneNode(true);
+        }
+        collapseWhitespace({
+            element: root,
+            isBlock: isBlock,
+            isVoid: isVoid,
+            isPre: options.preformattedCode ? isPreOrCode : null
+        });
+
+        return root
+    }
+
+    var _htmlParser;
+    function htmlParser () {
+        _htmlParser = _htmlParser || new HTMLParser();
+        return _htmlParser
+    }
+
+    function isPreOrCode (node) {
+        return node.nodeName === 'PRE' || node.nodeName === 'CODE'
+    }
+
+    function Node (node, options) {
+        node.isBlock = isBlock(node);
+        node.isCode = node.nodeName === 'CODE' || node.parentNode.isCode;
+        node.isBlank = isBlank(node);
+        node.flankingWhitespace = flankingWhitespace(node, options);
+        return node
+    }
+
+    function isBlank (node) {
+        return (
+            !isVoid(node) &&
+            !isMeaningfulWhenBlank(node) &&
+            /^\s*$/i.test(node.textContent) &&
+            !hasVoid(node) &&
+            !hasMeaningfulWhenBlank(node)
+        )
+    }
+
+    function flankingWhitespace (node, options) {
+        if (node.isBlock || (options.preformattedCode && node.isCode)) {
+            return { leading: '', trailing: '' }
+        }
+
+        var edges = edgeWhitespace(node.textContent);
+
+        // abandon leading ASCII WS if left-flanked by ASCII WS
+        if (edges.leadingAscii && isFlankedByWhitespace('left', node, options)) {
+            edges.leading = edges.leadingNonAscii;
+        }
+
+        // abandon trailing ASCII WS if right-flanked by ASCII WS
+        if (edges.trailingAscii && isFlankedByWhitespace('right', node, options)) {
+            edges.trailing = edges.trailingNonAscii;
+        }
+
+        return { leading: edges.leading, trailing: edges.trailing }
+    }
+
+    function edgeWhitespace (string) {
+        var m = string.match(/^(([ \t\r\n]*)(\s*))(?:(?=\S)[\s\S]*\S)?((\s*?)([ \t\r\n]*))$/);
+        return {
+            leading: m[1], // whole string for whitespace-only strings
+            leadingAscii: m[2],
+            leadingNonAscii: m[3],
+            trailing: m[4], // empty for whitespace-only strings
+            trailingNonAscii: m[5],
+            trailingAscii: m[6]
+        }
+    }
+
+    function isFlankedByWhitespace (side, node, options) {
+        var sibling;
+        var regExp;
+        var isFlanked;
+
+        if (side === 'left') {
+            sibling = node.previousSibling;
+            regExp = / $/;
+        } else {
+            sibling = node.nextSibling;
+            regExp = /^ /;
+        }
+
+        if (sibling) {
+            if (sibling.nodeType === 3) {
+                isFlanked = regExp.test(sibling.nodeValue);
+            } else if (options.preformattedCode && sibling.nodeName === 'CODE') {
+                isFlanked = false;
+            } else if (sibling.nodeType === 1 && !isBlock(sibling)) {
+                isFlanked = regExp.test(sibling.textContent);
+            }
+        }
+        return isFlanked
+    }
+
+    var reduce = Array.prototype.reduce;
+    var escapes = [
+        [/\\/g, '\\\\'],
+        [/\*/g, '\\*'],
+        [/^-/g, '\\-'],
+        [/^\+ /g, '\\+ '],
+        [/^(=+)/g, '\\$1'],
+        [/^(#{1,6}) /g, '\\$1 '],
+        [/`/g, '\\`'],
+        [/^~~~/g, '\\~~~'],
+        [/\[/g, '\\['],
+        [/\]/g, '\\]'],
+        [/^>/g, '\\>'],
+        [/_/g, '\\_'],
+        [/^(\d+)\. /g, '$1\\. ']
+    ];
+
+    function TurndownService (options) {
+        if (!(this instanceof TurndownService)) return new TurndownService(options)
+
+        var defaults = {
+            rules: rules,
+            headingStyle: 'setext',
+            hr: '* * *',
+            bulletListMarker: '*',
+            codeBlockStyle: 'indented',
+            fence: '```',
+            emDelimiter: '_',
+            strongDelimiter: '**',
+            linkStyle: 'inlined',
+            linkReferenceStyle: 'full',
+            br: '  ',
+            preformattedCode: false,
+            blankReplacement: function (content, node) {
+                return node.isBlock ? '\n\n' : ''
+            },
+            keepReplacement: function (content, node) {
+                return node.isBlock ? '\n\n' + node.outerHTML + '\n\n' : node.outerHTML
+            },
+            defaultReplacement: function (content, node) {
+                return node.isBlock ? '\n\n' + content + '\n\n' : content
+            }
+        };
+        this.options = extend({}, defaults, options);
+        this.rules = new Rules(this.options);
+    }
+
+    TurndownService.prototype = {
+        /**
+         * The entry point for converting a string or DOM node to Markdown
+         * @public
+         * @param {String|HTMLElement} input The string or DOM node to convert
+         * @returns A Markdown representation of the input
+         * @type String
+         */
+
+        turndown: function (input) {
+            if (!canConvert(input)) {
+                throw new TypeError(
+                    input + ' is not a string, or an element/document/fragment node.'
+                )
+            }
+
+            if (input === '') return ''
+
+            var output = process.call(this, new RootNode(input, this.options));
+            return postProcess.call(this, output)
+        },
+
+        /**
+         * Add one or more plugins
+         * @public
+         * @param {Function|Array} plugin The plugin or array of plugins to add
+         * @returns The Turndown instance for chaining
+         * @type Object
+         */
+
+        use: function (plugin) {
+            if (Array.isArray(plugin)) {
+                for (var i = 0; i < plugin.length; i++) this.use(plugin[i]);
+            } else if (typeof plugin === 'function') {
+                plugin(this);
+            } else {
+                throw new TypeError('plugin must be a Function or an Array of Functions')
+            }
+            return this
+        },
+
+        /**
+         * Adds a rule
+         * @public
+         * @param {String} key The unique key of the rule
+         * @param {Object} rule The rule
+         * @returns The Turndown instance for chaining
+         * @type Object
+         */
+
+        addRule: function (key, rule) {
+            this.rules.add(key, rule);
+            return this
+        },
+
+        /**
+         * Keep a node (as HTML) that matches the filter
+         * @public
+         * @param {String|Array|Function} filter The unique key of the rule
+         * @returns The Turndown instance for chaining
+         * @type Object
+         */
+
+        keep: function (filter) {
+            this.rules.keep(filter);
+            return this
+        },
+
+        /**
+         * Remove a node that matches the filter
+         * @public
+         * @param {String|Array|Function} filter The unique key of the rule
+         * @returns The Turndown instance for chaining
+         * @type Object
+         */
+
+        remove: function (filter) {
+            this.rules.remove(filter);
+            return this
+        },
+
+        /**
+         * Escapes Markdown syntax
+         * @public
+         * @param {String} string The string to escape
+         * @returns A string with Markdown syntax escaped
+         * @type String
+         */
+
+        escape: function (string) {
+            return escapes.reduce(function (accumulator, escape) {
+                return accumulator.replace(escape[0], escape[1])
+            }, string)
+        }
+    };
+
+    /**
+     * Reduces a DOM node down to its Markdown string equivalent
+     * @private
+     * @param {HTMLElement} parentNode The node to convert
+     * @returns A Markdown representation of the node
+     * @type String
+     */
+
+    function process (parentNode) {
+        var self = this;
+        return reduce.call(parentNode.childNodes, function (output, node) {
+            node = new Node(node, self.options);
+
+            var replacement = '';
+            if (node.nodeType === 3) {
+                replacement = node.isCode ? node.nodeValue : self.escape(node.nodeValue);
+            } else if (node.nodeType === 1) {
+                replacement = replacementForNode.call(self, node);
+            }
+
+            return join(output, replacement)
+        }, '')
+    }
+
+    /**
+     * Appends strings as each rule requires and trims the output
+     * @private
+     * @param {String} output The conversion output
+     * @returns A trimmed version of the ouput
+     * @type String
+     */
+
+    function postProcess (output) {
+        var self = this;
+        this.rules.forEach(function (rule) {
+            if (typeof rule.append === 'function') {
+                output = join(output, rule.append(self.options));
+            }
+        });
+
+        return output.replace(/^[\t\r\n]+/, '').replace(/[\t\r\n\s]+$/, '')
+    }
+
+    /**
+     * Converts an element node to its Markdown equivalent
+     * @private
+     * @param {HTMLElement} node The node to convert
+     * @returns A Markdown representation of the node
+     * @type String
+     */
+
+    function replacementForNode (node) {
+        var rule = this.rules.forNode(node);
+        var content = process.call(this, node);
+        var whitespace = node.flankingWhitespace;
+        if (whitespace.leading || whitespace.trailing) content = content.trim();
+        return (
+            whitespace.leading +
+            rule.replacement(content, node, this.options) +
+            whitespace.trailing
+        )
+    }
+
+    /**
+     * Joins replacement to the current output with appropriate number of new lines
+     * @private
+     * @param {String} output The current conversion output
+     * @param {String} replacement The string to append to the output
+     * @returns Joined output
+     * @type String
+     */
+
+    function join (output, replacement) {
+        var s1 = trimTrailingNewlines(output);
+        var s2 = trimLeadingNewlines(replacement);
+        var nls = Math.max(output.length - s1.length, replacement.length - s2.length);
+        var separator = '\n\n'.substring(0, nls);
+
+        return s1 + separator + s2
+    }
+
+    /**
+     * Determines whether an input can be converted
+     * @private
+     * @param {String|HTMLElement} input Describe this parameter
+     * @returns Describe what it returns
+     * @type String|Object|Array|Boolean|Number
+     */
+
+    function canConvert (input) {
+        return (
+            input != null && (
+                typeof input === 'string' ||
+                (input.nodeType && (
+                    input.nodeType === 1 || input.nodeType === 9 || input.nodeType === 11
+                ))
+            )
+        )
+    }
+
+    return TurndownService;
+
+}());

views/document/cherry_markdown_edit_template.tpl

@@ -389,7 +389,9 @@
 <script src="{{cdnjs "/static/js/custom-elements-builtin-0.6.5.min.js"}}" type="text/javascript"></script>
 <script src="{{cdnjs "/static/js/x-frame-bypass-1.0.2.js"}}" type="text/javascript"></script>
 <script src="{{cdnjs "/static/mammoth/mammoth.browser.js"}}" type="text/javascript"></script>
+<script src="{{cdnjs "/static/turndown/turndown.js"}}" type="text/javascript"></script>
 <script src="{{cdnjs "/static/js/word-to-html.js"}}" type="text/javascript"></script>
+<script src="{{cdnjs "/static/js/html-to-markdown.js"}}" type="text/javascript"></script>
 <script type="text/javascript">
     $(function () {
         

views/document/markdown_edit_template.tpl

@@ -100,6 +100,8 @@
 
             <a href="javascript:;" data-toggle="tooltip" data-title="{{i18n .Lang "doc.word_to_html"}}"><i class="fa fa-file-word-o last" name="wordToContent"></i></a>
 
+            <a href="javascript:;" data-toggle="tooltip" data-title="{{i18n .Lang "doc.html_to_markdown"}}"><i class="fa fa-html5 last" name="htmlToMarkdown"></i></a>
+
         </div>
 
         <div class="editormd-group pull-right">
@@ -459,7 +461,9 @@
 <script src="{{cdnjs "/static/js/custom-elements-builtin-0.6.5.min.js"}}" type="text/javascript"></script>
 <script src="{{cdnjs "/static/js/x-frame-bypass-1.0.2.js"}}" type="text/javascript"></script>
 <script src="{{cdnjs "/static/mammoth/mammoth.browser.js"}}" type="text/javascript"></script>
+<script src="{{cdnjs "/static/turndown/turndown.js"}}" type="text/javascript"></script>
 <script src="{{cdnjs "/static/js/word-to-html.js"}}" type="text/javascript"></script>
+<script src="{{cdnjs "/static/js/html-to-markdown.js"}}" type="text/javascript"></script>
 <script type="text/javascript">
     $(function () {
         editLangPath = {{cdnjs "/static/editor.md/languages/"}} + lang