Difference between revisions of "HTTP Client Module"
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If <code><http:header name="Accept-Encoding" value="gzip"/></code> is specified and if the addressed web server provides support for the {{Code|gzip}} compression algorithm, the response will automatically be decompressed. | If <code><http:header name="Accept-Encoding" value="gzip"/></code> is specified and if the addressed web server provides support for the {{Code|gzip}} compression algorithm, the response will automatically be decompressed. | ||
+ | |||
+ | Please note that BaseX provides extensions to the specification: | ||
+ | |||
+ | * Since {{Announce|Version 11}}, {{Code|csv}}, {{Code|json}} and {{Code|html}} parser options can be supplied to influence the conversion of the response. | ||
+ | |||
+ | Since BaseX 10, the module is based on the [https://openjdk.org/groups/net/httpclient/intro.html Java HTTP Client], which provides a better overall performance, uses internal connection pools and follows redirects across different protocols (http, https). | ||
=Conventions= | =Conventions= | ||
All functions in this module are assigned to the <code><nowiki>http://expath.org/ns/http-client</nowiki></code> namespace, which is statically bound to the {{Code|http}} prefix.<br/> | All functions in this module are assigned to the <code><nowiki>http://expath.org/ns/http-client</nowiki></code> namespace, which is statically bound to the {{Code|http}} prefix.<br/> | ||
− | All errors are assigned to the <code><nowiki>http://expath.org/ns/error</nowiki></code> namespace, which is statically bound to the {{Code| | + | All errors are assigned to the <code><nowiki>http://expath.org/ns/error</nowiki></code> namespace, which is statically bound to the {{Code|experr}} prefix. |
=Functions= | =Functions= | ||
==http:send-request== | ==http:send-request== | ||
+ | |||
+ | {{Announce|Updated with Version 11:}} {{Code|csv}}, {{Code|json}}, {{Code|html}} and {{Code|text}} attributes added. | ||
{| width='100%' | {| width='100%' | ||
− | |- | + | |- valign="top" |
− | | width='120' | ''' | + | | width='120' | '''Signature''' |
− | | | + | |<pre>http:send-request( |
− | |- | + | $request as element(http:request)?, |
+ | $href as xs:string? := (), | ||
+ | $bodies as item()* := () | ||
+ | ) as item()+</pre> | ||
+ | |- valign="top" | ||
| '''Summary''' | | '''Summary''' | ||
− | |Sends an HTTP request and interprets the corresponding response | + | |Sends an HTTP request and interprets the corresponding response: |
− | |- | + | * {{Code|$request}} contains an {{Code|<http:request/>}} element with a {{Code|method}} attribute, an {{Code|href}} attribute with the target URI, and optional header and body elements. |
+ | * The request is either sent to the URI of the {{Code|$href}} argument or (if empty) to the URI supplied via the {{Code|href}} attribute. | ||
+ | * In addition to the attributes of the official specification, {{Code|csv}}, {{Code|json}}, {{Code|html}} and {{Code|text}} attributes can be supplied to define how to convert the response body (see [[#Response Conversion|Response Conversion]] for an example). | ||
+ | |||
+ | Notes: | ||
+ | * Both basic and digest authentication is supported. | ||
+ | * While the contents of the request can be supplied as child of the {{Code|http:body}} element, it is faster and safer to pass them on via the third argument. | ||
+ | * Certificate verification can be globally disabled via the {{Option|IGNORECERT}} option. | ||
+ | * For further information, please check out the [http://expath.org/spec/http-client EXPath] specification. | ||
+ | |- valign="top" | ||
|'''Errors''' | |'''Errors''' | ||
|{{Error|HC0001|#Errors}} an HTTP error occurred.<br/>{{Error|HC0002|#Errors}} error parsing the entity content as XML or HTML.<br/>{{Error|HC0003|#Errors}} with a multipart response, the override-media-type must be either a multipart media type or application/octet-stream.<br/>{{Error|HC0004|#Errors}} the src attribute on the body element is mutually exclusive with all other attribute (except the media-type).<br/>{{Error|HC0005|#Errors}} the request element is not valid.<br/>{{Error|HC0006|#Errors}} a timeout occurred waiting for the response. | |{{Error|HC0001|#Errors}} an HTTP error occurred.<br/>{{Error|HC0002|#Errors}} error parsing the entity content as XML or HTML.<br/>{{Error|HC0003|#Errors}} with a multipart response, the override-media-type must be either a multipart media type or application/octet-stream.<br/>{{Error|HC0004|#Errors}} the src attribute on the body element is mutually exclusive with all other attribute (except the media-type).<br/>{{Error|HC0005|#Errors}} the request element is not valid.<br/>{{Error|HC0006|#Errors}} a timeout occurred waiting for the response. | ||
Line 27: | Line 48: | ||
==Status Only== | ==Status Only== | ||
+ | |||
Simple GET request. As the attribute {{Code|status-only}} is set to true, only the response element is returned. | Simple GET request. As the attribute {{Code|status-only}} is set to true, only the response element is returned. | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'>http:send-request(<http:request method='get' status-only='true'/>, 'http://basex.org')</pre> |
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang="xml"><http:response status="200" message="OK"> |
<http:header name="Date" value="Mon, 14 Mar 2011 20:55:53 GMT"/> | <http:header name="Date" value="Mon, 14 Mar 2011 20:55:53 GMT"/> | ||
<http:header name="Content-Length" value="12671"/> | <http:header name="Content-Length" value="12671"/> | ||
Line 47: | Line 69: | ||
==Google Homepage== | ==Google Homepage== | ||
− | Retrieve the Google search home page with a timeout of 10 seconds. In order to [[Parsers# | + | Retrieve the Google search home page with a timeout of 10 seconds. In order to [[Parsers#HTMLParser|parse HTML]], TagSoup must be contained in the class path. |
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'>http:send-request(<http:request method='get' href='http://www.google.com' timeout='10'/>)</pre> |
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang="xml"> |
<http:response status="200" message="OK"> | <http:response status="200" message="OK"> | ||
<http:header name="Date" value="Mon, 14 Mar 2011 22:03:25 GMT"/> | <http:header name="Date" value="Mon, 14 Mar 2011 22:03:25 GMT"/> | ||
Line 66: | Line 88: | ||
<html xmlns="http://www.w3.org/1999/xhtml"> | <html xmlns="http://www.w3.org/1999/xhtml"> | ||
<head> | <head> | ||
− | <meta http-equiv=" | + | <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> |
<title>Google</title> | <title>Google</title> | ||
− | + | ... | |
− | |||
− | |||
− | |||
</body> | </body> | ||
</html> | </html> | ||
Line 79: | Line 98: | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
let $binary := http:send-request( | let $binary := http:send-request( | ||
<http:request method='get' | <http:request method='get' | ||
Line 99: | Line 118: | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'>http:send-request(<http:request method='get'/>, 'http://upload.wikimedia.org/wikipedia/commons/6/6b/Bitmap_VS_SVG.svg')</pre> |
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang="xml"><http:response status="200" message="OK"> |
<http:header name="ETag" value="W/"11b6d-4ba15ed4""/> | <http:header name="ETag" value="W/"11b6d-4ba15ed4""/> | ||
<http:header name="Age" value="9260"/> | <http:header name="Age" value="9260"/> | ||
Line 129: | Line 148: | ||
'''Query:''' | '''Query:''' | ||
− | <pre | + | <pre lang='xquery'> |
− | + | http:send-request( | |
− | <http:request | + | <http:request method='post' username='admin' password='admin'> |
− | + | <http:body media-type='application/xml'/> | |
− | <http:body media-type='application/xml'> | + | </http:request>, |
− | + | 'http://localhost:8080/rest', | |
− | + | <query> | |
− | + | <text> | |
− | + | <html>{ | |
− | + | for $i in 1 to 3 | |
− | + | return <div>Section {$i }</div> | |
− | + | }</html> | |
− | + | </text> | |
− | + | </query> | |
− | + | ) | |
− | |||
</pre> | </pre> | ||
'''Result:''' | '''Result:''' | ||
− | <pre | + | <pre lang="xml"> |
<http:response xmlns:http="http://expath.org/ns/http-client" status="200" message="OK"> | <http:response xmlns:http="http://expath.org/ns/http-client" status="200" message="OK"> | ||
<http:header name="Content-Length" value="135"/> | <http:header name="Content-Length" value="135"/> | ||
Line 161: | Line 179: | ||
</html> | </html> | ||
</pre> | </pre> | ||
+ | |||
+ | ==File Upload== | ||
+ | |||
+ | Performs an HTML file upload. In the RESTXQ code, the uploaded file is written to the temporary directory: | ||
+ | |||
+ | '''Query:''' | ||
+ | |||
+ | <pre lang='xquery'> | ||
+ | let $path := 'file-to-be.uploaded' | ||
+ | return http:send-request( | ||
+ | <http:request method='POST'> | ||
+ | <http:multipart media-type='multipart/form-data'> | ||
+ | <http:header name='content-disposition' | ||
+ | value='form-data; name="files"; filename="{ file:name($path) }"'/> | ||
+ | <http:body media-type='application/octet-stream'/> | ||
+ | </http:multipart> | ||
+ | </http:request>, | ||
+ | 'http://localhost:8080/write-to-temp', | ||
+ | file:read-binary($path) | ||
+ | ) | ||
+ | </pre> | ||
+ | |||
+ | '''RESTXQ service:''' | ||
+ | |||
+ | <pre lang='xquery'> | ||
+ | declare | ||
+ | %rest:POST | ||
+ | %rest:path('/write-to-temp') | ||
+ | %rest:form-param('files', '{$files}') | ||
+ | function dba:file-upload( | ||
+ | $files as map(xs:string, xs:base64Binary) | ||
+ | ) as empty-sequence() { | ||
+ | map:for-each($files, function($file, $content) { | ||
+ | file:write-binary(file:temp-dir() || $file, $content) | ||
+ | }); | ||
+ | }; | ||
+ | </pre> | ||
+ | |||
+ | ==Response Conversion== | ||
+ | |||
+ | CSV, JSON and HTML responses are automatically converted to an XML representation. The target format can be influenced by supplying {{Code|csv}}, {{Code|json}} and {{Code|html}} attributes: | ||
+ | |||
+ | '''Query:''' | ||
+ | |||
+ | <pre lang='xquery'> | ||
+ | http:send-request(<http:request method='GET' href='http://localhost:8080/json' json='format=xquery,lax=true'/>) | ||
+ | </pre> | ||
+ | |||
+ | '''Result:''' | ||
+ | <pre lang="javascript"> | ||
+ | map { "abcde": 12345 } | ||
+ | </pre> | ||
+ | |||
+ | Without the {{Code|json}} attribute, the response body is converted to the default XML representation: | ||
+ | |||
+ | <pre lang="xml"> | ||
+ | <json type="object"> | ||
+ | <abcde>12345</abcde> | ||
+ | </json> | ||
+ | </pre> | ||
+ | |||
+ | '''RESTXQ service:''' | ||
+ | |||
+ | <pre lang='xquery'> | ||
+ | declare | ||
+ | %rest:path('json') | ||
+ | %output:method('json') | ||
+ | function local:json() { | ||
+ | map { 'abcde': 12345 } | ||
+ | }; | ||
+ | </pre> | ||
+ | |||
+ | See the [[CSV Module]], [[JSON Module]] and [[HTML Module]] for a list of the available options. | ||
=Errors= | =Errors= | ||
Line 167: | Line 258: | ||
! width="110"|Code | ! width="110"|Code | ||
|Description | |Description | ||
− | |- | + | |- valign="top" |
|{{Code|HC0001}} | |{{Code|HC0001}} | ||
|An HTTP error occurred. | |An HTTP error occurred. | ||
− | |- | + | |- valign="top" |
|{{Code|HC0002}} | |{{Code|HC0002}} | ||
|Error parsing the entity content as XML or HTML. | |Error parsing the entity content as XML or HTML. | ||
− | |- | + | |- valign="top" |
|{{Code|HC0003}} | |{{Code|HC0003}} | ||
|With a multipart response, the override-media-type must be either a multipart media type or application/octet-stream. | |With a multipart response, the override-media-type must be either a multipart media type or application/octet-stream. | ||
− | |- | + | |- valign="top" |
|{{Code|HC0004}} | |{{Code|HC0004}} | ||
|The src attribute on the body element is mutually exclusive with all other attribute (except the media-type). | |The src attribute on the body element is mutually exclusive with all other attribute (except the media-type). | ||
− | |- | + | |- valign="top" |
|{{Code|HC0005}} | |{{Code|HC0005}} | ||
|The request element is not valid. | |The request element is not valid. | ||
− | |- | + | |- valign="top" |
|{{Code|HC0006}} | |{{Code|HC0006}} | ||
|A timeout occurred waiting for the response. | |A timeout occurred waiting for the response. | ||
Line 188: | Line 279: | ||
=Changelog= | =Changelog= | ||
+ | |||
+ | ;Version 11.0 | ||
+ | * Updated: {{Function||http:send-request}}: {{Code|csv}}, {{Code|json}}, {{Code|html}} and {{Code|text}} attributes added. | ||
+ | |||
+ | ;Version 10.0 | ||
+ | * Updated: Implementation based on the new [https://openjdk.org/groups/net/httpclient/intro.html Java HTTP Client]. | ||
;Version 9.0 | ;Version 9.0 | ||
Line 196: | Line 293: | ||
;Version 7.6 | ;Version 7.6 | ||
− | * Updated: | + | * Updated: {{Function||http:send-request}}: {{Code|HC0002}} is raised if the input cannot be parsed or converted to the final data type. |
* Updated: errors are using {{Code|text/plain}} as media-type. | * Updated: errors are using {{Code|text/plain}} as media-type. |
Latest revision as of 18:38, 1 December 2023
This XQuery Module contains a single function to send HTTP requests and handle HTTP responses. The function send-request
is based on the EXPath HTTP Client Module. It gives full control over the available request and response parameters. For simple GET requests, the Fetch Module may be sufficient.
If <http:header name="Accept-Encoding" value="gzip"/>
is specified and if the addressed web server provides support for the gzip
compression algorithm, the response will automatically be decompressed.
Please note that BaseX provides extensions to the specification:
- Since Version 11,
csv
,json
andhtml
parser options can be supplied to influence the conversion of the response.
Since BaseX 10, the module is based on the Java HTTP Client, which provides a better overall performance, uses internal connection pools and follows redirects across different protocols (http, https).
Contents
Conventions[edit]
All functions in this module are assigned to the http://expath.org/ns/http-client
namespace, which is statically bound to the http
prefix.
All errors are assigned to the http://expath.org/ns/error
namespace, which is statically bound to the experr
prefix.
Functions[edit]
http:send-request[edit]
Updated with Version 11: csv
, json
, html
and text
attributes added.
Signature | http:send-request( $request as element(http:request)?, $href as xs:string? := (), $bodies as item()* := () ) as item()+ |
Summary | Sends an HTTP request and interprets the corresponding response:
Notes:
|
Errors | HC0001 : an HTTP error occurred.HC0002 : error parsing the entity content as XML or HTML.HC0003 : with a multipart response, the override-media-type must be either a multipart media type or application/octet-stream.HC0004 : the src attribute on the body element is mutually exclusive with all other attribute (except the media-type).HC0005 : the request element is not valid.HC0006 : a timeout occurred waiting for the response.
|
Examples[edit]
Status Only[edit]
Simple GET request. As the attribute status-only
is set to true, only the response element is returned.
Query:
http:send-request(<http:request method='get' status-only='true'/>, 'http://basex.org')
Result:
<http:response status="200" message="OK">
<http:header name="Date" value="Mon, 14 Mar 2011 20:55:53 GMT"/>
<http:header name="Content-Length" value="12671"/>
<http:header name="Expires" value="Mon, 14 Mar 2011 20:57:23 GMT"/>
<http:header name="Set-Cookie" value="fe_typo_user=d10c9552f9a784d1a73f8b6ebdf5ce63; path=/"/>
<http:header name="Connection" value="close"/>
<http:header name="Content-Type" value="text/html; charset=utf-8"/>
<http:header name="Server" value="Apache/2.2.16"/>
<http:header name="X-Powered-By" value="PHP/5.3.5"/>
<http:header name="Cache-Control" value="max-age=90"/>
<http:body media-type="text/html; charset=utf-8"/>
</http:response>
Google Homepage[edit]
Retrieve the Google search home page with a timeout of 10 seconds. In order to parse HTML, TagSoup must be contained in the class path.
Query:
http:send-request(<http:request method='get' href='http://www.google.com' timeout='10'/>)
Result:
<http:response status="200" message="OK">
<http:header name="Date" value="Mon, 14 Mar 2011 22:03:25 GMT"/>
<http:header name="Transfer-Encoding" value="chunked"/>
<http:header name="Expires" value="-1"/>
<http:header name="X-XSS-Protection" value="1; mode=block"/>
<http:header name="Set-Cookie" value="...; expires=Tue, 13-Sep-2011 22:03:25 GMT; path=/; domain=.google.ch; HttpOnly"/>
<http:header name="Content-Type" value="text/html; charset=ISO-8859-1"/>
<http:header name="Server" value="gws"/>
<http:header name="Cache-Control" value="private, max-age=0"/>
<http:body media-type="text/html; charset=ISO-8859-1"/>
</http:response>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>Google</title>
...
</body>
</html>
The response content type can also be overwritten in order to retrieve HTML pages and other textual data as plain string (using text/plain
) or in its binary representation (using application/octet-stream
). With the http:header
element, a custom user agent can be set. See the following example:
Query:
let $binary := http:send-request(
<http:request method='get'
override-media-type='application/octet-stream'
href='http://www.google.com'>
<http:header name="User-Agent" value="Opera"/>
</http:request>
)[2]
return try {
html:parse($binary)
} catch * {
'Conversion to XML failed: ' || $err:description
}
SVG Data[edit]
Content-type ending with +xml, e.g. image/svg+xml.
Query:
http:send-request(<http:request method='get'/>, 'http://upload.wikimedia.org/wikipedia/commons/6/6b/Bitmap_VS_SVG.svg')
Result:
<http:response status="200" message="OK">
<http:header name="ETag" value="W/"11b6d-4ba15ed4""/>
<http:header name="Age" value="9260"/>
<http:header name="Date" value="Mon, 14 Mar 2011 19:17:10 GMT"/>
<http:header name="Content-Length" value="72557"/>
<http:header name="Last-Modified" value="Wed, 17 Mar 2010 22:59:32 GMT"/>
<http:header name="Content-Type" value="image/svg+xml"/>
<http:header name="X-Cache-Lookup" value="MISS from knsq22.knams.wikimedia.org:80"/>
<http:header name="Connection" value="keep-alive"/>
<http:header name="Server" value="Sun-Java-System-Web-Server/7.0"/>
<http:header name="X-Cache" value="MISS from knsq22.knams.wikimedia.org"/>
<http:body media-type="image/svg+xml"/>
</http:response>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="1063" height="638">
<defs>
<linearGradient id="lg0">
<stop stop-color="#3333ff" offset="0"/>
<stop stop-color="#3f3fff" stop-opacity="0" offset="1"/>
</linearGradient>
...
</svg>
POST Request[edit]
POST request to the BaseX REST Service, specifying a username and password.
Query:
http:send-request(
<http:request method='post' username='admin' password='admin'>
<http:body media-type='application/xml'/>
</http:request>,
'http://localhost:8080/rest',
<query>
<text>
<html>{
for $i in 1 to 3
return <div>Section {$i }</div>
}</html>
</text>
</query>
)
Result:
<http:response xmlns:http="http://expath.org/ns/http-client" status="200" message="OK">
<http:header name="Content-Length" value="135"/>
<http:header name="Content-Type" value="application/xml"/>
<http:header name="Server" value="Jetty(6.1.26)"/>
<http:body media-type="application/xml"/>
</http:response>
<html>
<div>Section 1</div>
<div>Section 2</div>
<div>Section 3</div>
</html>
File Upload[edit]
Performs an HTML file upload. In the RESTXQ code, the uploaded file is written to the temporary directory:
Query:
let $path := 'file-to-be.uploaded'
return http:send-request(
<http:request method='POST'>
<http:multipart media-type='multipart/form-data'>
<http:header name='content-disposition'
value='form-data; name="files"; filename="{ file:name($path) }"'/>
<http:body media-type='application/octet-stream'/>
</http:multipart>
</http:request>,
'http://localhost:8080/write-to-temp',
file:read-binary($path)
)
RESTXQ service:
declare
%rest:POST
%rest:path('/write-to-temp')
%rest:form-param('files', '{$files}')
function dba:file-upload(
$files as map(xs:string, xs:base64Binary)
) as empty-sequence() {
map:for-each($files, function($file, $content) {
file:write-binary(file:temp-dir() || $file, $content)
});
};
Response Conversion[edit]
CSV, JSON and HTML responses are automatically converted to an XML representation. The target format can be influenced by supplying csv
, json
and html
attributes:
Query:
http:send-request(<http:request method='GET' href='http://localhost:8080/json' json='format=xquery,lax=true'/>)
Result:
map { "abcde": 12345 }
Without the json
attribute, the response body is converted to the default XML representation:
<json type="object">
<abcde>12345</abcde>
</json>
RESTXQ service:
declare
%rest:path('json')
%output:method('json')
function local:json() {
map { 'abcde': 12345 }
};
See the CSV Module, JSON Module and HTML Module for a list of the available options.
Errors[edit]
Code | Description |
---|---|
HC0001
|
An HTTP error occurred. |
HC0002
|
Error parsing the entity content as XML or HTML. |
HC0003
|
With a multipart response, the override-media-type must be either a multipart media type or application/octet-stream. |
HC0004
|
The src attribute on the body element is mutually exclusive with all other attribute (except the media-type). |
HC0005
|
The request element is not valid. |
HC0006
|
A timeout occurred waiting for the response. |
Changelog[edit]
- Version 11.0
- Updated:
http:send-request
:csv
,json
,html
andtext
attributes added.
- Version 10.0
- Updated: Implementation based on the new Java HTTP Client.
- Version 9.0
- Updated: support for gzipped content encoding
- Version 8.0
- Added: digest authentication
- Version 7.6
- Updated:
http:send-request
:HC0002
is raised if the input cannot be parsed or converted to the final data type. - Updated: errors are using
text/plain
as media-type.