Load template engine for website output using theme configuration

1 files changed, 98 insertions, 0 deletions

diff --git a/lib/output/website.js b/lib/output/website.js
new file mode 100644
index 0000000..41395e6
--- /dev/null
+++ b/lib/output/website.js
@@ -0,0 +1,98 @@
+var _ = require('lodash');
+var path = require('path');
+var util = require('util');
+var nunjucks = require('nunjucks');
+
+var Promise = require('../utils/promise');
+var conrefsLoader = require('./conrefs');
+var Output = require('./base');
+
+// Tranform a theme ID into a plugin
+function themeID(plugin) {
+    return 'theme-' + plugin;
+}
+
+function WebsiteOutput() {
+    Output.apply(this, arguments);
+
+    // Nunjucks environment
+    this.env;
+
+    // Plugin instance for the main theme
+    this.theme;
+
+    // Plugin instance for the default theme
+    this.defaultTheme;
+}
+util.inherits(WebsiteOutput, Output);
+
+// Name of the generator
+// It's being used as a prefix for templates
+WebsiteOutput.prototype.name = 'website';
+
+// Load and setup the theme
+WebsiteOutput.prototype.prepare = function() {
+    var that = this;
+
+    return Promise()
+    .then(function() {
+        return WebsiteOutput.super_.prototype.prepare.apply(that);
+    })
+
+    .then(function() {
+        var themeName = that.book.config.get('theme');
+        that.theme = that.plugins.get(themeID(themeName));
+        that.themeDefault = that.plugins.get(themeID('default'));
+
+        if (!that.theme) {
+            throw new Error('Theme "' + themeName + '" is not installed, add "' + themeID(themeName) + '" to your "book.json"');
+        }
+
+        var searchPaths = _.chain([
+            // The book itself can contains a "_layouts" folder
+            that.book.root,
+
+            // Installed plugin (it can be identical to themeDefault.root)
+            that.theme.root,
+
+            // Is default theme still installed
+            that.themeDefault? that.themeDefault.root : null
+        ])
+        .compact()
+        .uniq()
+        .value();
+
+        that.env = new nunjucks.Environment(new nunjucks.FileSystemLoader(searchPaths));
+    });
+};
+
+// Write a page (parsable file)
+WebsiteOutput.prototype.onPage = function(page) {
+    var that = this;
+
+    // Render the page template with the same context as the json output
+    return this.render('page', this.getPageContext(page))
+
+    // Write the HTML file
+    .then(function(html) {
+        return that.writeFile(
+            page.withExtension('.html'),
+            html
+        );
+    });
+};
+
+// ----- Utilities ----
+
+// Render a template using nunjucks
+// Templates are stored in `_layouts` folders
+WebsiteOutput.prototype.render = function(tpl, context) {
+    return Promise.nfcall(this.env.render.bind(this.env), this.templateName(tpl), context);
+};
+
+// Return a complete name for a template
+WebsiteOutput.prototype.templateName = function(name) {
+    return path.join('_layouts', this.name, name+'.html');
+};
+
+module.exports = conrefsLoader(WebsiteOutput);