Add method .hook to plugins

2 files changed, 31 insertions, 0 deletions

diff --git a/lib/plugins/index.js b/lib/plugins/index.js
index 6eb788b..343c569 100644
--- a/lib/plugins/index.js
+++ b/lib/plugins/index.js
@@ -95,7 +95,13 @@ PluginsManager.prototype.install = function() {
         return registry.install(that.book, plugin.name, plugin.version);
     })
     .thenResolve(plugins.length);
+};
 
+// Call a hook on all plugins to transform an input
+PluginsManager.prototype.hook = function(name, input) {
+    return Promise.reduce(this.plugins, function(current, plugin) {
+        return plugin.hook(name, current);
+    }, input);
 };
 
 module.exports = PluginsManager;
diff --git a/lib/plugins/plugin.js b/lib/plugins/plugin.js
index ae8886c..9f9cc35 100644
--- a/lib/plugins/plugin.js
+++ b/lib/plugins/plugin.js
@@ -7,6 +7,10 @@ var error = require('../utils/error');
 var gitbook = require('../gitbook');
 var registry = require('./registry');
 
+var HOOKS = [
+    'init', 'finish', 'finish:before', 'config', 'page', 'page:before'
+];
+
 // 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) {
@@ -109,4 +113,25 @@ BookPlugin.prototype.validate = function() {
     }
 };
 
+// Call a hook and returns its result
+BookPlugin.prototype.hook = function(name, input) {
+    // Our book will be the context to apply
+    var context = this.book;
+
+    var hookFunc = this.content.hooks? this.content.hooks[name] : null;
+    input = input || {};
+
+    if (!hookFunc) return Promise(input);
+
+    this.book.log.debug.ln('call hook "' + name + '" for plugin "' + this.id + '"');
+    if (!_.contains(HOOKS, name)) {
+        this.book.log.warn.ln('hook "'+name+'" used by plugin "'+this.name+'" is deprecated, and will be removed in the coming versions');
+    }
+
+    return Promise()
+    .then(function() {
+        return hookFunc.apply(context, [input]);
+    });
+};
+
 module.exports = BookPlugin;