[docs] revision of the article "Engine Overview"

This patch revision of the article "Engine Overview":

- add links & anchors
- improve formating of the tables

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
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Markus Heiser 2021-06-03 18:53:00 +02:00
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.. _engines-dev: .. _engines-dev:
=============== ===============
Engine overview Engine Overview
=============== ===============
.. _metasearch-engine: https://en.wikipedia.org/wiki/Metasearch_engine .. _metasearch-engine: https://en.wikipedia.org/wiki/Metasearch_engine
.. sidebar:: Further reading ..
- :ref:`general engine settings`
- :ref:`settings engine`
.. contents::
:depth: 3
:backlinks: entry
searx is a metasearch-engine_, so it uses different search engines to provide searx is a metasearch-engine_, so it uses different search engines to provide
better results. better results.
@ -14,297 +22,296 @@ 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 engine, an adapter has to be built between searx and the external search
engines. Adapters are stored under the folder :origin:`searx/engines`. engines. Adapters are stored under the folder :origin:`searx/engines`.
.. contents::
:depth: 3
:backlinks: entry
.. _general engine configuration: .. _general engine configuration:
general engine configuration General Engine Configuration
============================ ============================
It is required to tell searx the type of results the engine provides. The 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 arguments can be set in the engine file or in the settings file (normally
(normally ``settings.yml``). The arguments in the settings file override ``settings.yml``). The arguments in the settings file override the ones in the
the ones in the engine file. engine file.
It does not matter if an option is stored in the engine file or in the It does not matter if an option is stored in the engine file or in the settings.
settings. However, the standard way is the following: However, the standard way is the following:
.. _engine file: .. _engine file:
engine file Engine File
----------- -----------
======================= =========== ======================================================== .. table:: Common options in the engine module
argument type information :width: 100%
======================= =========== ========================================================
categories list pages, in which the engine is working ======================= =========== ========================================================
paging boolean support multible pages argument type information
time_range_support boolean support search time range ======================= =========== ========================================================
engine_type str ``online`` by default, other possibles values are categories list pages, in which the engine is working
``offline``, ``online_dictionnary``, ``online_currency`` paging boolean support multible pages
======================= =========== ======================================================== time_range_support boolean support search time range
engine_type str - ``online`` :ref:`[ref] <demo online engine>` by
default, other possibles values are:
- ``offline`` :ref:`[ref] <offline engines>`
- ``online_dictionary``
- ``online_currency``
======================= =========== ========================================================
.. _engine settings: .. _engine settings:
settings.yml Engine ``settings.yml``
------------ -----------------------
======================= =========== ============================================= For a more detailed description, see :ref:`settings engine` in the :ref:`settings.yml`.
argument type information
======================= =========== =============================================
name string name of search-engine
engine string name of searx-engine
(filename without ``.py``)
enable_http bool enable HTTP
(by default only HTTPS is enabled).
shortcut string shortcut of search-engine
timeout string specific timeout for search-engine
display_error_messages boolean display error messages on the web UI
proxies dict set proxies for a specific engine
(e.g. ``proxies : {http: socks5://proxy:port,
https: socks5://proxy:port}``)
======================= =========== =============================================
.. table:: Common options in the engine setup (``settings.yml``)
:width: 100%
overrides ======================= =========== ===============================================
argument type information
======================= =========== ===============================================
name string name of search-engine
engine string name of searx-engine (filename without ``.py``)
enable_http bool enable HTTP (by default only HTTPS is enabled).
shortcut string shortcut of search-engine
timeout string specific timeout for search-engine
display_error_messages boolean display error messages on the web UI
proxies dict set proxies for a specific engine
(e.g. ``proxies : {http: socks5://proxy:port,
https: socks5://proxy:port}``)
======================= =========== ===============================================
.. _engine overrides:
Overrides
--------- ---------
A few of the options have default values in the engine, but are often .. sidebar:: engine's global names
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 Global names with a leading underline are *private to the engine* and will
following: not be overwritten.
======================= =========== =========================================== A few of the options have default values in the namespace of engine's python
argument type information modul, 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
base_url string base-url, can be overwritten to use same searx will not start with that engine.
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 Here is an very simple example of the global names in the namespace of engine's
------------ module:
.. code:: python .. code:: python
# engine dependent config # engine dependent config
categories = ['general'] categories = ['general']
paging = True paging = True
_non_overwritten_global = 'foo'
.. table:: The naming of overrides is arbitrary / recommended overrides are:
:width: 100%
======================= =========== ===========================================
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
======================= =========== ===========================================
.. _engine request: .. _engine request:
making a request Making a Request
================ ================
To perform a search an URL have to be specified. In addition to specifying an To perform a search an URL have to be specified. In addition to specifying an
URL, arguments can be passed to the query. URL, arguments can be passed to the query.
passed arguments .. _engine request arguments:
----------------
Passed Arguments (request)
--------------------------
These arguments can be used to construct the search query. Furthermore, These arguments can be used to construct the search query. Furthermore,
parameters with default value can be redefined for special purposes. parameters with default value can be redefined for special purposes.
If the ``engine_type`` is ``online```:
====================== ============== ======================================================================== .. table:: If the ``engine_type`` is ``online``
argument type default-value, information :width: 100%
====================== ============== ========================================================================
url str ``''`` ====================== ============== ========================================================================
method str ``'GET'`` argument type default-value, information
headers set ``{}`` ====================== ============== ========================================================================
data set ``{}`` url str ``''``
cookies set ``{}`` method str ``'GET'``
verify bool ``True`` headers set ``{}``
headers.User-Agent str a random User-Agent data set ``{}``
category str current category, like ``'general'`` cookies set ``{}``
safesearch int ``0``, between ``0`` and ``2`` (normal, moderate, strict) verify bool ``True``
time_range Optional[str] ``None``, can be ``day``, ``week``, ``month``, ``year`` headers.User-Agent str a random User-Agent
pageno int current pagenumber category str current category, like ``'general'``
language str specific language code like ``'en_US'``, or ``'all'`` if unspecified safesearch int ``0``, between ``0`` and ``2`` (normal, moderate, strict)
====================== ============== ======================================================================== time_range Optional[str] ``None``, can be ``day``, ``week``, ``month``, ``year``
pageno int current pagenumber
language str specific language code like ``'en_US'``, or ``'all'`` if unspecified
====================== ============== ========================================================================
If the ``engine_type`` is ``online_dictionnary```, in addition to the ``online`` arguments: .. table:: If the ``engine_type`` is ``online_dictionary``, in addition to the
``online`` arguments:
:width: 100%
====================== ============ ======================================================================== ====================== ============== ========================================================================
argument type default-value, information argument type default-value, information
====================== ============ ======================================================================== ====================== ============== ========================================================================
from_lang str specific language code like ``'en_US'`` from_lang str specific language code like ``'en_US'``
to_lang str specific language code like ``'en_US'`` to_lang str specific language code like ``'en_US'``
query str the text query without the languages query str the text query without the languages
====================== ============ ======================================================================== ====================== ============== ========================================================================
If the ``engine_type`` is ``online_currency```, in addition to the ``online`` arguments: .. table:: If the ``engine_type`` is ``online_currency```, in addition to the
``online`` arguments:
:width: 100%
====================== ============ ======================================================================== ====================== ============== ========================================================================
argument type default-value, information argument type default-value, information
====================== ============ ======================================================================== ====================== ============== ========================================================================
amount float the amount to convert amount float the amount to convert
from str ISO 4217 code from str ISO 4217 code
to str ISO 4217 code to str ISO 4217 code
from_name str currency name from_name str currency name
to_name str currency name to_name str currency name
====================== ============ ======================================================================== ====================== ============== ========================================================================
parsed arguments Specify Request
---------------- ---------------
The function ``def request(query, params):`` always returns the ``params`` The function :py:func:`def request(query, params):
variable. Inside searx, the following paramters can be used to specify a search <searx.engines.demo_online.request>` always returns the ``params`` variable, the
request: following parameters can be used to specify a search request:
=================== =========== ========================================================================== .. table::
argument type information :width: 100%
=================== =========== ==========================================================================
url str requested url
method str HTTP request method
headers set HTTP header information
data set HTTP data information
cookies set HTTP cookies
verify bool Performing SSL-Validity check
allow_redirects bool Follow redirects
max_redirects int maximum redirects, hard limit
soft_max_redirects int maximum redirects, soft limit. Record an error but don't stop the engine
raise_for_httperror bool True by default: raise an exception if the HTTP code of response is >= 300
=================== =========== ==========================================================================
=================== =========== ==========================================================================
example code argument type information
------------ =================== =========== ==========================================================================
url str requested url
.. code:: python method str HTTP request method
headers set HTTP header information
# search-url data set HTTP data information
base_url = 'https://example.com/' cookies set HTTP cookies
search_string = 'search?{query}&page={page}' verify bool Performing SSL-Validity check
allow_redirects bool Follow redirects
# do search-request max_redirects int maximum redirects, hard limit
def request(query, params): soft_max_redirects int maximum redirects, soft limit. Record an error but don't stop the engine
search_path = search_string.format( raise_for_httperror bool True by default: raise an exception if the HTTP code of response is >= 300
query=urlencode({'q': query}), =================== =========== ==========================================================================
page=params['pageno'])
params['url'] = base_url + search_path
return params
.. _engine results: .. _engine results:
.. _engine media types:
returned results Media Types
================ ===========
Searx is able to return results of different media-types. Currently the Each result item of an engine can be of different media-types. Currently the
following media-types are supported: following media-types are supported. To set another media-type as ``default``,
the parameter ``template`` must be set to the desired type.
- default_ .. table:: Parameter of the **default** media type:
- images_ :width: 100%
- videos_
- torrent_
- map_
To set another media-type as default, the parameter ``template`` must be set to ========================= =====================================================
the desired type. 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
========================= =====================================================
default
-------
========================= ===================================================== .. table:: Parameter of the **images** media type:
result-parameter information :width: 100%
========================= =====================================================
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 ========================= =====================================================
------ 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
========================= =====================================================
To use this template, the parameter:
========================= ===================================================== .. table:: Parameter of the **videos** media type:
result-parameter information :width: 100%
========================= =====================================================
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``
result-parameter information ========================= =====================================================
========================= ===================================================== url string, url of the result
template is set to ``videos.html`` title string, title of the result
url string, url of the result content *(not implemented yet)*
title string, title of the result publishedDate :py:class:`datetime.datetime`, time of publish
content *(not implemented yet)* thumbnail string, url to a small-preview image
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 .. _magnetlink: https://en.wikipedia.org/wiki/Magnet_URI_scheme
========================= ===================================================== .. table:: Parameter of the **torrent** media type:
result-parameter information :width: 100%
========================= =====================================================
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
========================= =====================================================
========================= =====================================================
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 .. table:: Parameter of the **map** media type:
--- :width: 100%
========================= ===================================================== ========================= =====================================================
result-parameter information result-parameter information
========================= ===================================================== ------------------------- -----------------------------------------------------
url string, url of the result template is set to ``map.html``
title string, title of the result ========================= =====================================================
content string, general result-text url string, url of the result
publishedDate :py:class:`datetime.datetime`, time of publish title string, title of the result
latitude latitude of result (in decimal format) content string, general result-text
longitude longitude of result (in decimal format) publishedDate :py:class:`datetime.datetime`, time of publish
boundingbox boundingbox of result (array of 4. values latitude latitude of result (in decimal format)
``[lat-min, lat-max, lon-min, lon-max]``) longitude longitude of result (in decimal format)
geojson geojson of result (https://geojson.org/) boundingbox boundingbox of result (array of 4. values
osm.type type of osm-object (if OSM-Result) ``[lat-min, lat-max, lon-min, lon-max]``)
osm.id id of osm-object (if OSM-Result) geojson geojson of result (https://geojson.org/)
address.name name of object osm.type type of osm-object (if OSM-Result)
address.road street name of object osm.id id of osm-object (if OSM-Result)
address.house_number house number of object address.name name of object
address.locality city, place of object address.road street name of object
address.postcode postcode of object address.house_number house number of object
address.country country of object address.locality city, place of object
========================= ===================================================== address.postcode postcode of object
address.country country of object
========================= =====================================================