searxng/docs/dev/engine_overview.rst
Alexandre Flament ca93a01844 [mod] dynamically set language_support variable
The language_support variable is set to True by default,
and set to False in only 5 engines.

Except the documentation and the /config URL, this variable is not used.

This commit remove the variable definition in the engines, and
set value according to supported_languages length: False when the length is 0,
True otherwise.

Close #2485
2021-02-01 17:10:37 +01:00

13 KiB

Engine overview

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 searx/engines.

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

argument type information
categories list pages, in which the engine is working
paging boolean support multible pages
time_range_support boolean support search time range

engine_type

str

online by default, other possibles values are offline, online_dictionnary, online_currency

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

proxies

dict

set proxies for a specific engine (e.g. proxies : {http: socks5://proxy:port, https: socks5://proxy:port})

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

# engine dependent config
categories = ['general']
paging = 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.

If the engine_type is online`:

argument type default-value, information
url str ''
method str 'GET'
headers set {}
data set {}
cookies set {}
verify bool True
headers.User-Agent str a random User-Agent
category str current category, like 'general'
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:

argument type default-value, information
from_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

If the engine_type is online_currency, in addition to the online` arguments:

argument type default-value, information
amount float the amount to convert
from str ISO 4217 code
to str ISO 4217 code
from_name str currency name
to_name str currency name

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 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
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

# 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:

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 :pydatetime.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

:pydatetime.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 :pydatetime.datetime, time of publish
thumbnail string, url to a small-preview image

torrent

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

:pydatetime.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 :pydatetime.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 (https://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