[doc] update docs/dev/plugins.rst

docs/dev/plugins.rst

@@ -26,8 +26,8 @@ Example plugin
    # attach callback to the post search hook
    #  request: flask request object
    #  ctx: the whole local context of the post search hook
-   def post_search(request, ctx):
-       ctx['search'].suggestions.add('example')
+   def post_search(request, search):
+       search.result_container.suggestions.add('example')
        return True
 
 External plugins
@@ -50,20 +50,52 @@ Plugin entry points
 
 Entry points (hooks) define when a plugin runs. Right now only three hooks are
 implemented. So feel free to implement a hook if it fits the behaviour of your
-plugin.
+plugin. A plugin doesn't need to implement all the hooks.
 
-Pre search hook
----------------
 
-Runs BEFORE the search request. Function to implement: ``pre_search``
+.. py:function:: pre_search(request, search) -> bool
 
-Post search hook
-----------------
+   Runs BEFORE the search request.
 
-Runs AFTER the search request. Function to implement: ``post_search``
+   `search.result_container` can be changed.
 
-Result hook
------------
+   Return a boolean:
 
-Runs when a new result is added to the result list. Function to implement:
-``on_result``
+   * True to continue the search
+   * False to stop the search
+
+   :param flask.request request:
+   :param searx.search.SearchWithPlugins search:
+   :return: False to stop the search
+   :rtype: bool
+
+
+.. py:function:: post_search(request, search) -> None
+
+   Runs AFTER the search request.
+
+   :param flask.request request: Flask request.
+   :param searx.search.SearchWithPlugins search: Context.
+
+
+.. py:function:: on_result(request, search, result) -> bool
+
+   Runs for each result of each engine.
+
+   `result` can be changed.
+
+   If `result["url"]` is defined, then `result["parsed_url"] = urlparse(result['url'])`
+
+   .. warning::
+      `result["url"]` can be changed, but `result["parsed_url"]` must be updated too.
+
+   Return a boolean:
+
+   * True to keep the result
+   * False to remove the result
+
+   :param flask.request request:
+   :param searx.search.SearchWithPlugins search:
+   :param typing.Dict result: Result, see - :ref:`engine results`
+   :return: True to keep the result
+   :rtype: bool