[enh] add external plugin support

searx/plugins/__init__.py

@@ -14,8 +14,14 @@ along with searx. If not, see < http://www.gnu.org/licenses/ >.
 
 (C) 2015 by Adam Tauber, <asciimoo@gmail.com>
 '''
+
+from importlib import import_module
+from os.path import abspath, basename, dirname, exists, join
+from shutil import copyfile
 from sys import exit, version_info
-from searx import logger
+from traceback import print_exc
+
+from searx import logger, settings, static_path
 
 if version_info[0] == 3:
     unicode = str
@@ -54,7 +60,9 @@ class PluginStore():
         for plugin in self.plugins:
             yield plugin
 
-    def register(self, *plugins):
+    def register(self, *plugins, external=False):
+        if external:
+            plugins = load_external_plugins(plugins)
         for plugin in plugins:
             for plugin_attr, plugin_attr_type in required_attrs:
                 if not hasattr(plugin, plugin_attr) or not isinstance(getattr(plugin, plugin_attr), plugin_attr_type):
@@ -77,6 +85,54 @@ class PluginStore():
         return ret
 
 
+def load_external_plugins(plugin_names):
+    plugins = []
+    for name in plugin_names:
+        logger.debug('loading plugin: {0}'.format(name))
+        try:
+            pkg = import_module(name)
+        except Exception as e:
+            logger.critical('failed to load plugin module {0}: {1}'.format(name, e))
+            exit(3)
+
+        pkg.__base_path = dirname(abspath(pkg.__file__))
+
+        fix_package_resources(pkg, name)
+
+        plugins.append(pkg)
+        logger.debug('plugin "{0}" loaded'.format(name))
+    return plugins
+
+
+def check_resource(base_path, resource_path, name, dir_prefix):
+        dep_path = join(base_path, resource_path)
+        file_name = basename(dep_path)
+        resource_name = '{0}_{1}'.format('_'.join(name.split()), file_name)
+        resource_path = join(static_path, 'plugins', dir_prefix, resource_name)
+        if not exists(resource_path):
+            try:
+                copyfile(dep_path, resource_path)
+            except:
+                logger.critical('failed to copy plugin resource {0} for plugin {1}'.format(resource_name, name))
+                exit(3)
+
+        # returning with the web path of the resource
+        return join('plugins', dir_prefix, resource_name)
+
+
+def fix_package_resources(pkg, name):
+    if hasattr(pkg, 'js_dependencies'):
+        pkg.js_dependencies = tuple([
+            check_resource(pkg.__base_path, x, name, 'js')
+            for x in pkg.js_dependencies
+        ])
+    if hasattr(pkg, 'css_dependencies'):
+        pkg.css_dependencies = tuple([
+            check_resource(pkg.__base_path, x, name, 'css')
+            for x in pkg.css_dependencies
+        ])
+
+
 plugins = PluginStore()
 plugins.register(oa_doi_rewrite)
 plugins.register(https_rewrite)
@@ -86,3 +142,6 @@ plugins.register(self_info)
 plugins.register(search_on_category_select)
 plugins.register(tracker_url_remover)
 plugins.register(vim_hotkeys)
+# load external plugins
+if 'plugins' in settings:
+    plugins.register(*settings['plugins'], external=True)