searx/docs/dev/engine_overview.rst

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.. _engines-dev:
===============
Engine overview
===============
.. _metasearch-engine: https://en.wikipedia.org/wiki/Metasearch_engine
searx is a metasearch-engine_, so it uses different search engines to provide
better results.
Because there is no general search API which could be used for every search
engine, an adapter has to be built between searx and the external search
engines. Adapters are stored under the folder :origin:`searx/engines`.
.. contents::
:depth: 3
:backlinks: entry
general engine configuration
============================
It is required to tell searx the type of results the engine provides. The
arguments can be set in the engine file or in the settings file
(normally ``settings.yml``). The arguments in the settings file override
the ones in the engine file.
It does not matter if an option is stored in the engine file or in the
settings. However, the standard way is the following:
.. _engine file:
engine file
-----------
======================= =========== ===========================================
argument type information
======================= =========== ===========================================
categories list pages, in which the engine is working
paging boolean support multible pages
language_support boolean support language choosing
time_range_support boolean support search time range
offline boolean engine runs offline
======================= =========== ===========================================
.. _engine settings:
settings.yml
------------
======================= =========== ===========================================
argument type information
======================= =========== ===========================================
name string name of search-engine
engine string name of searx-engine
(filename without ``.py``)
shortcut string shortcut of search-engine
timeout string specific timeout for search-engine
display_error_messages boolean display error messages on the web UI
======================= =========== ===========================================
overrides
---------
A few of the options have default values in the engine, but are often
overwritten by the settings. If ``None`` is assigned to an option in the engine
file, it has to be redefined in the settings, otherwise searx will not start
with that engine.
The naming of overrides is arbitrary. But the recommended overrides are the
following:
======================= =========== ===========================================
argument type information
======================= =========== ===========================================
base_url string base-url, can be overwritten to use same
engine on other URL
number_of_results int maximum number of results per request
language string ISO code of language and country like en_US
api_key string api-key if required by engine
======================= =========== ===========================================
example code
------------
.. code:: python
# engine dependent config
categories = ['general']
paging = True
language_support = True
making a request
================
To perform a search an URL have to be specified. In addition to specifying an
URL, arguments can be passed to the query.
passed arguments
----------------
These arguments can be used to construct the search query. Furthermore,
parameters with default value can be redefined for special purposes.
====================== ============ ========================================================================
argument type default-value, information
====================== ============ ========================================================================
url string ``''``
method string ``'GET'``
headers set ``{}``
data set ``{}``
cookies set ``{}``
verify boolean ``True``
headers.User-Agent string a random User-Agent
category string current category, like ``'general'``
started datetime current date-time
pageno int current pagenumber
language string specific language code like ``'en_US'``, or ``'all'`` if unspecified
====================== ============ ========================================================================
parsed arguments
----------------
The function ``def request(query, params):`` always returns the ``params``
variable. Inside searx, the following paramters can be used to specify a search
request:
============ =========== =========================================================
argument type information
============ =========== =========================================================
url string requested url
method string HTTP request method
headers set HTTP header information
data set HTTP data information (parsed if ``method != 'GET'``)
cookies set HTTP cookies
verify boolean Performing SSL-Validity check
============ =========== =========================================================
example code
------------
.. code:: python
# search-url
base_url = 'https://example.com/'
search_string = 'search?{query}&page={page}'
# do search-request
def request(query, params):
search_path = search_string.format(
query=urlencode({'q': query}),
page=params['pageno'])
params['url'] = base_url + search_path
return params
returned results
================
Searx is able to return results of different media-types. Currently the
following media-types are supported:
- default_
- images_
- videos_
- torrent_
- map_
To set another media-type as default, the parameter ``template`` must be set to
the desired type.
default
-------
========================= =====================================================
result-parameter information
========================= =====================================================
url string, url of the result
title string, title of the result
content string, general result-text
publishedDate :py:class:`datetime.datetime`, time of publish
========================= =====================================================
images
------
To use this template, the parameter:
========================= =====================================================
result-parameter information
========================= =====================================================
template is set to ``images.html``
url string, url to the result site
title string, title of the result *(partly implemented)*
content *(partly implemented)*
publishedDate :py:class:`datetime.datetime`,
time of publish *(partly implemented)*
img\_src string, url to the result image
thumbnail\_src string, url to a small-preview image
========================= =====================================================
videos
------
========================= =====================================================
result-parameter information
========================= =====================================================
template is set to ``videos.html``
url string, url of the result
title string, title of the result
content *(not implemented yet)*
publishedDate :py:class:`datetime.datetime`, time of publish
thumbnail string, url to a small-preview image
========================= =====================================================
torrent
-------
.. _magnetlink: https://en.wikipedia.org/wiki/Magnet_URI_scheme
========================= =====================================================
result-parameter information
========================= =====================================================
template is set to ``torrent.html``
url string, url of the result
title string, title of the result
content string, general result-text
publishedDate :py:class:`datetime.datetime`,
time of publish *(not implemented yet)*
seed int, number of seeder
leech int, number of leecher
filesize int, size of file in bytes
files int, number of files
magnetlink string, magnetlink_ of the result
torrentfile string, torrentfile of the result
========================= =====================================================
map
---
========================= =====================================================
result-parameter information
========================= =====================================================
url string, url of the result
title string, title of the result
content string, general result-text
publishedDate :py:class:`datetime.datetime`, time of publish
latitude latitude of result (in decimal format)
longitude longitude of result (in decimal format)
boundingbox boundingbox of result (array of 4. values
``[lat-min, lat-max, lon-min, lon-max]``)
geojson geojson of result (http://geojson.org)
osm.type type of osm-object (if OSM-Result)
osm.id id of osm-object (if OSM-Result)
address.name name of object
address.road street name of object
address.house_number house number of object
address.locality city, place of object
address.postcode postcode of object
address.country country of object
========================= =====================================================