More refactoring to easily handle multiple renderers

ReactNativeClient/lib/renderers/MdToHtml/rules/html_image.js

@@ -0,0 +1,49 @@
+const Entities = require('html-entities').AllHtmlEntities;
+const htmlentities = (new Entities()).encode;
+const Resource = require('lib/models/Resource.js');
+const htmlUtils = require('lib/htmlUtils.js');
+const utils = require('../../utils');
+
+function renderImageHtml(before, src, after, ruleOptions) {
+	const r = utils.imageReplacement(src, ruleOptions.resources, ruleOptions.resourceBaseUrl);
+	if (typeof r === 'string') return r;
+	if (r) return '<img ' + before + ' ' + htmlUtils.attributesHtml(r) + ' ' + after + '/>';
+	return '[Image: ' + htmlentities(resource.title) + ' (' + htmlentities(mime) + ')]';
+}
+
+function installRule(markdownIt, mdOptions, ruleOptions) {
+	const htmlBlockDefaultRender = markdownIt.renderer.rules.html_block || function(tokens, idx, options, env, self) {
+		return self.renderToken(tokens, idx, options);
+	};
+
+	const htmlInlineDefaultRender = markdownIt.renderer.rules.html_inline || function(tokens, idx, options, env, self) {
+		return self.renderToken(tokens, idx, options);
+	};
+
+	const imageRegex = /<img(.*?)src=["'](.*?)["'](.*?)>/gi
+
+	const handleImageTags = function(defaultRender) {
+		return function(tokens, idx, options, env, self) {
+			const token = tokens[idx];
+			const content = token.content;
+
+			if (!content.match(imageRegex)) return defaultRender(tokens, idx, options, env, self);
+
+			return content.replace(imageRegex, (v, before, src, after) => {
+				if (!Resource.isResourceUrl(src)) return defaultRender(tokens, idx, options, env, self);
+				return renderImageHtml(before, src, after, ruleOptions);
+			});
+		}
+	}
+
+	// It seems images sometimes are inline, sometimes a block
+	// to make sure they both render correctly.
+	markdownIt.renderer.rules.html_block = handleImageTags(htmlBlockDefaultRender);
+	markdownIt.renderer.rules.html_inline = handleImageTags(htmlInlineDefaultRender);
+}
+
+module.exports = function(context, ruleOptions) {
+	return function(md, mdOptions) {
+		installRule(md, mdOptions, ruleOptions);
+	};
+};