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var _ = require("underscore");
function markdownElement(start, end) {
if (end === undefined) {
end = start;
}
this.open = function(attrs) {
return start;
};
this.close = function() {
return end;
};
}
function markdownLink() {
var href;
this.open = function(attributes) {
href = attributes.href;
return "[";
};
this.close = function() {
return "](" + (href || "") + ")";
};
this.anchorPosition = "before";
}
function markdownImage() {
this.open = function(attributes) {
var src = attributes.src || "";
var altText = attributes.alt || "";
if (src || altText) {
return "![" + altText + "](" + src + ")";
}
};
this.close = function() {
return "";
};
}
function markdownList() {
this.open = function(attrs) {
return attrs.indent > -1 ? "\n" : "";
};
this.close = function(attrs) {
return attrs.indent > -1 ? "" : "\n";
};
}
function markdownListItem() {
this.open = function(attrs) {
var output = "";
for(var i = 0; i < attrs.indent; ++i) {
output += "\t";
}
return output + (attrs.type === "ul" ? "-" : attrs.count + ".") + " ";
};
this.close = function() {
return "\n";
};
}
// map HTML tags to Markdown syntax
var htmlmarkdown = {
// paragraphs elements use three line feeds to close
// this prevents them being caught by collapsing list elements in `asString`
// while still allowing them to be collapsed when multiple empty lines are removed
"p": new markdownElement("", "\n\n\n"),
"br": new markdownElement("", " \n"),
"ul": new markdownList(),
"ol": new markdownList(),
"li": new markdownListItem(),
"strong": new markdownElement("**"),
"em": new markdownElement("*"),
"a": new markdownLink(),
"img": new markdownImage(),
};
(function() {
for (var i = 1; i <= 6; i++) {
htmlmarkdown["h" + i] = new markdownElement(repeatString("#", i) + " ", "\n\n\n");
}
})();
function repeatString(value, count) {
return new Array(count + 1).join(value);
}
function markdownWriter() {
var fragments = [];
var listStack = [];
var list = {
indent: -1,
type: "ul",
count: 0
};
function isList(tagName) {
return tagName === "ul" || tagName === "ol";
}
function open(tagName, attributes) {
attributes = attributes || {};
var idHasBeenWritten = false;
if (htmlmarkdown[tagName]) {
if (htmlmarkdown[tagName].anchorPosition === "before") {
writeAnchor(attributes);
idHasBeenWritten = true;
}
if (tagName === "li") {
attributes.indent = list.indent;
attributes.type = list.type;
attributes.count = ++list.count;
} else if (isList(tagName)) {
attributes.indent = list.indent;
}
fragments.push(htmlmarkdown[tagName].open(attributes));
if (isList(tagName)) {
listStack.push(_.clone(list));
list.type = tagName;
list.indent++;
list.count = 0;
}
}
if (!idHasBeenWritten) {
writeAnchor(attributes);
}
}
function writeAnchor(attributes) {
if (attributes.id) {
fragments.push('<a id="' + attributes.id + '"></a>');
}
}
function close(tagName) {
if (htmlmarkdown[tagName]) {
if (isList(tagName)) {
list = listStack.pop();
}
fragments.push(htmlmarkdown[tagName].close(list));
}
}
function selfClosing(tagName, attributes) {
open(tagName, attributes);
close(tagName);
}
function text(value) {
fragments.push(escapeMarkdown(value));
}
function append(html) {
fragments.push(html);
}
function asString() {
// massage the output to collapse mulitple empty lines and empty lines between nested lists
return fragments.join("").replace(/\n{2}(\t*)([2-9]\d*\.|- )/g, "\n$1$2").replace(/\n{3,}/g, "\n\n");
}
return {
asString: asString,
open: open,
close: close,
text: text,
selfClosing: selfClosing,
append: append
};
}
exports.writer = markdownWriter;
function escapeMarkdown(value) {
return value
.replace(/\\/g, '\\\\')
.replace(/([\`\*_\{\}\[\]\(\)\#\+\-\.\!])/g, '\\$1');
}
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