1 files changed, 83 insertions, 0 deletions
diff --git a/lib/plugins/loadPlugin.js b/lib/plugins/loadPlugin.js
new file mode 100644
index 0000000..400146e
--- /dev/null
+++ b/lib/plugins/loadPlugin.js
@@ -0,0 +1,83 @@
+var path = require('path');
+var resolve = require('resolve');
+var Immutable = require('immutable');
+
+var Promise = require('../utils/promise');
+var error = require('../utils/error');
+var timing = require('../utils/timing');
+
+var validatePlugin = require('./validatePlugin');
+
+// Return true if an error is a "module not found"
+// Wait on https://github.com/substack/node-resolve/pull/81 to be merged
+function isModuleNotFound(err) {
+    return err.code == 'MODULE_NOT_FOUND' || err.message.indexOf('Cannot find module') >= 0;
+}
+
+/**
+    Load a plugin in a book
+
+    @param {Book} book
+    @param {Plugin} plugin
+    @param {String} pkgPath (optional)
+    @return {Promise<Plugin>}
+*/
+function loadPlugin(book, plugin) {
+    var logger = book.getLogger();
+
+    var name = plugin.getName();
+    var pkgPath = plugin.getPath();
+
+    // Try loading plugins from different location
+    var p = Promise()
+    .then(function() {
+        var packageContent;
+        var content;
+
+        // Locate plugin and load package.json
+        try {
+            var res = resolve.sync('./package.json', { basedir: pkgPath });
+
+            pkgPath = path.dirname(res);
+            packageContent = require(res);
+        } catch (err) {
+            if (!isModuleNotFound(err)) throw err;
+
+            packageContent = undefined;
+            content = undefined;
+
+            return;
+        }
+
+        // Load plugin JS content
+        try {
+            content = require(pkgPath);
+        } catch(err) {
+            // It's no big deal if the plugin doesn't have an "index.js"
+            // (For example: themes)
+            if (isModuleNotFound(err)) {
+                content = {};
+            } else {
+                throw new error.PluginError(err, {
+                    plugin: name
+                });
+            }
+        }
+
+        // Update plugin
+        return plugin.merge({
+            'package': Immutable.fromJS(packageContent),
+            'content': Immutable.fromJS(content)
+        });
+    })
+
+    .then(validatePlugin);
+
+    p = timing.measure('plugin.load', p);
+
+    logger.info('loading plugin "' + name + '"... ');
+    return logger.info.promise(p);
+}
+
+
+module.exports = loadPlugin;