Difference between revisions of "REST"

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This page presents one of the [[Web Application]] services. It describes how to use the REST API of BaseX.
 
This page presents one of the [[Web Application]] services. It describes how to use the REST API of BaseX.
  
BaseX offers a RESTful API for accessing database resources via URLs.
+
BaseX offers a RESTful API for accessing database resources via URLs. REST ([https://en.wikipedia.org/wiki/Representational_State_Transfer REpresentational State Transfer]) facilitates a simple and fast access to databases through HTTP. The HTTP methods GET, PUT, DELETE, and POST can be used to interact with the database.
REST ([http://en.wikipedia.org/wiki/Representational_State_Transfer REpresentational State Transfer])
 
facilitates a simple and fast access to databases through HTTP. The HTTP methods
 
GET, PUT, DELETE, and POST can be used to interact with the database.
 
  
 
=Usage=
 
=Usage=
  
By default, REST services are available at {{Code|http://localhost:8984/rest/}}. If no default credentials are specified in the URL or when starting the web application, they will be requested by the client ([[Web Application#User Management|see further]]).
+
By default, REST services are available at {{Code|http://localhost:8080/rest/}}. If no default credentials are specified in the URL or when starting the web application, they will be requested by the client ([[Web Application#User Management|see further]]).
  
 
A web browser can be used to perform simple GET-based REST requests and display the response. Some alternatives for using REST are listed in the [[#Usage Examples|Usage Examples]].
 
A web browser can be used to perform simple GET-based REST requests and display the response. Some alternatives for using REST are listed in the [[#Usage Examples|Usage Examples]].
 +
 +
Since BaseX 10, results in the {{Code|rest}} namespace are returned unprefixed:
 +
 +
<pre lang="xml">
 +
<!-- before -->
 +
<rest:databases xmlns:rest="http://basex.org/rest"/>
 +
 +
<!-- before -->
 +
<databases xmlns="http://basex.org/rest"/>
 +
</pre>
  
 
=URL Architecture=
 
=URL Architecture=
 +
 +
A request to the root URL returns all available databases:
 
   
 
   
The root URL lists all available databases. The following examples assume that
+
:<code>http://localhost:8080/rest</code>
you have created a database instance from the [http://files.basex.org/xml/factbook.xml factbook.xml] document:
 
 
   
 
   
:<code>http://localhost:8984/rest</code>
+
<pre lang="xml">
+
<databases xmlns="http://basex.org/rest">
<pre class="brush:xml">  
+
   <database resources="25742" size="43813599">articles</database>
<rest:databases resources="1" xmlns:rest="http://basex.org/rest">
+
  ...
   <rest:database resources="1" size="1813599">factbook</rest:database>
+
</databases>
</rest:databases>
+
</pre>
</pre>  
+
 
 +
The resources of a database (directories, resource metadata) are listed if a database and an optional directory path is specified:
  
The resources of a database can be listed by specifying the database, and potential sub directories, in the URL.
+
:<code>http://localhost:8080/rest/articles</code>
In the given example, a single XML document is stored in the ''factbook'' database:
 
  
:<code>http://localhost:8984/rest/factbook</code>
+
<pre lang="xml">
 +
<database name="articles" xmlns="http://basex.org/rest">
 +
  <dir>binaries</dir>
 +
  <resource type="xml" content-type="application/xml" size="77192">1973-02-08-xltp325.xml</resource>
 +
  ...
 +
</database>
 +
</pre>
  
<pre class="brush:xml">
+
If the path to a single resource is specified, the resource itself will be returned:
<rest:database name="factbook" resources="1" xmlns:rest="http://basex.org/rest">
 
  <rest:resource type="xml" content-type="application/xml" size="77192">factbook.xml</rest:resource>
 
</rest:database>
 
</pre>
 
 
The contents of a database can be retrieved by directly addressing the resource:
 
 
   
 
   
:<code>http://localhost:8984/rest/factbook/factbook.xml</code>
+
:<code>http://localhost:8080/rest/articles/1973-02-08-xltp325.xml</code>
 
If a resource is not found, an HTTP response will be generated with <code>404</code> as status code.
 
 
   
 
   
 
==Parameters==
 
==Parameters==
Line 57: Line 63:
 
==GET Method==
 
==GET Method==
 
   
 
   
If the GET method is used, all query parameters are directly specified within the URL.
+
If the GET method is used, all query parameters are directly specified within the URL. Additionally, the following '''operations''' can be specified:
Additionally, the following '''operations''' can be specified:
 
  
* {{Code|query}}: Evaluate an XQuery expression. If a database or database path is specified in the URL, it is used as initial query context.
+
* {{Code|query}}: Evaluate an XQuery expression. If a database or database path is specified in the URL, it is set as query context.
 
* {{Code|command}}: Execute a single [[Commands|database command]].
 
* {{Code|command}}: Execute a single [[Commands|database command]].
* {{Code|run}}: Evaluate an XQuery file or command script located on the server. The file path is resolved against the directory specified by <code>[[Options#WEBPATH|RESTPATH]]</code> (before, it was resolved against <code>[[Options#WEBPATH|WEBPATH]]</code>).
+
* {{Code|run}}: Evaluate an XQuery file or command script located on the server. The file path is resolved against the {{Option|RESTPATH}} directory. Similar to {{Code|query}}, a database or database path is set as context. With {{Announce|Version 11}}, if no file is found and if the file suffix has been omitted, the extensions {{Code|.xq}} and {{Code|.bxs}} are successively attached to the supplied filename.
  
 
; Examples
 
; Examples
  
* Lists all resources found in the '''tmp''' path of the ''factbook'' database:<br/><code>http://localhost:8984/rest/factbook/tmp</code>
+
* Lists all resources found in the '''tmp''' path of the ''factbook'' database:<br/><code>http://localhost:8080/rest/factbook/tmp</code>
 +
* Returns the number of documents in a database called ''test'':<br/><code>http://localhost:8080/rest/test?query=count(.)</code>
 +
* Serializes a document as JsonML:<br/><code>http://localhost:8080/rest/factbook/factbook.xml?method=json&json=format=jsonml</code>
 +
* <code>US-ASCII</code> is chosen as output encoding, and the query <code>eval.xq</code> is evaluated:<br/><code>http://localhost:8080/rest?run=eval&encoding=US-ASCII</code>
 +
* The next URL lists all database users who are known to BaseX:<br/><code>http://localhost:8080/rest?command=show+users</code>
  
* Serializes a document as JSONML:<br/><code>http://localhost:8984/rest/factbook/factbook.xml?method=json&json=format=jsonml</code>
+
==POST Method==
  
* <code>US-ASCII</code> is chosen as output encoding, and the query <code>eval.xq</code> is evaluated:<br/><code>http://localhost:8984/rest?run=eval.xq&encoding=US-ASCII</code>
+
The body of a POST request is interpreted as XML fragment, which specifies the operation to perform.
 +
The name of the root element determines how the body will be evaluated:
  
* The next URL lists all database users that are known to BaseX:<br/><code>http://localhost:8984/rest?command=show+users</code>
+
* {{Code|commands}}: Run [[Commands#Command Scripts|Command Script]]
 +
* {{Code|query}}: Execute XQuery expression
 +
* {{Code|run}}: Run server-side file (query or command script)
 +
* {{Code|command}}: Execute single command  
  
==POST Method==
+
The root element may be bound to the optional REST namespace. Existing command scripts can be sent to the server without any modifications.
 +
 
 +
For the other commands, the following child elements are supported:
  
The body of a POST request is interpreted as XML fragment, which specifies the
+
{| class="wikitable"
operation to perform. The body must conform to a given [[REST: POST Schema|XML Schema]].
+
|-
 +
! Name
 +
! Description
 +
|-
 +
| {{Code|text}}
 +
| Required; contains the query string, command string, or file to be run
 +
|-
 +
| {{Code|parameter}}
 +
| Serialization parameter (with {{Code|@name}} and {{Code|@value}} attributes)
 +
|-
 +
| {{Code|option}}
 +
| Database option (with {{Code|@name}} and {{Code|@value}} attributes)
 +
|-
 +
| {{Code|variable}}
 +
| Variable bindings
 +
|-
 +
| {{Code|context}}
 +
| Initial context item
 +
|}
  
 
; Examples
 
; Examples
  
* The following query returns the first five city names of the <b>factbook</b> database:  
+
Create an empty database and return database information:
<pre class="brush:xml">
+
 
<query xmlns="http://basex.org/rest">
+
<pre lang="xml">
   <text><![CDATA[ (//city/name)[position() <= 5] ]]></text>
+
<commands>
</query>
+
  <create-db name='db'/>
 +
  <info-db/>
 +
</commands>
 +
</pre>
 +
 
 +
Return the first five city names of the <b>factbook</b> database:
 +
 
 +
<pre lang="xml">
 +
<rest xmlns="http://basex.org/rest">
 +
   <rest><![CDATA[ (//city/name)[position() <= 5] ]]></text>
 +
</rest>
 
</pre>
 
</pre>
  
* The second query returns the string lengths of all text nodes, which are found in the node that has been specified as initial context node:
+
Return string lengths of all text nodes that are found in the node that has been specified as initial context node:
<pre class="brush:xml">
+
 
<rest:query xmlns:rest="http://basex.org/rest">
+
<pre lang="xml">
   <rest:text>for $i in .//text() return string-length($i)</rest:text>
+
<query>
   <rest:context>
+
   <text>for $i in .//text() return string-length($i)</text>
 +
   <context>
 
     <xml>
 
     <xml>
 
       <text>Hello</text>
 
       <text>Hello</text>
 
       <text>World</text>
 
       <text>World</text>
 
     </xml>
 
     </xml>
   </rest:context>
+
   </context>
</rest:query>
+
</query>
 
</pre>
 
</pre>
  
* The following request returns the registered database users encoded in <code>ISO-8859-1</code>:
+
Return the registered database users encoded in <code>ISO-8859-1</code>:
<pre class="brush:xml">
+
 
<command xmlns="http://basex.org/rest">
+
<pre lang="xml">
 +
<command>
 
   <text>show users</text>
 
   <text>show users</text>
 
   <parameter name='encoding' value='ISO-8859-1'/>
 
   <parameter name='encoding' value='ISO-8859-1'/>
Line 109: Line 154:
 
</pre>
 
</pre>
  
* This example creates a new database from the specified input and retains all whitespaces:
+
Create a new database from the specified input and preserve all whitespaces:
<pre class="brush:xml">
+
 
<command xmlns="http://basex.org/rest">
+
<pre lang="xml">
 +
<command>
 
   <text>create db test http://files.basex.org/xml/xmark.xml</text>
 
   <text>create db test http://files.basex.org/xml/xmark.xml</text>
 
   <option name='chop' value='false'/>
 
   <option name='chop' value='false'/>
Line 117: Line 163:
 
</pre>
 
</pre>
  
* The last request runs a query <code>query.xq</code> located in the directory specified by <code>[[Options#WEBPATH|WEBPATH]]</code>:
+
Bind value to the {{Code|$person}} variable and run query <code>find-person.xq</code>:
<pre class="brush:xml">
+
 
<run xmlns="http://basex.org/rest">
+
<pre lang="xml">
   <text>query.xq</text>
+
<run>
 +
  <variable name='person' value='Johannes Müller'/>
 +
   <text>find-person.xq</text>
 
</run>
 
</run>
 
</pre>
 
</pre>
Line 133: Line 181:
 
There are two ways to store non-XML data in BaseX:
 
There are two ways to store non-XML data in BaseX:
  
* '''Store as raw''':<br/> If <code>application/octet-stream</code> is chosen as content-type, the input data is added as raw.
+
* '''Store as Raw Data''':<br/> If <code>application/octet-stream</code> is chosen as content-type, the input is added as [[Binary Data]].
 
* '''Convert to XML''':<br/> Incoming data is converted to XML if a parser is available for the specified content-type. The following content types are supported:
 
* '''Convert to XML''':<br/> Incoming data is converted to XML if a parser is available for the specified content-type. The following content types are supported:
 
** <code>application/json</code>: Stores JSON as XML.
 
** <code>application/json</code>: Stores JSON as XML.
Line 146: Line 194:
 
; Examples
 
; Examples
  
* A new database with the name <b>XMark</b> is created. If XML input is sent in the HTTP body, the resulting database resource will be called <b>XMark.xml</b>:<br/><code><nowiki>http://localhost:8984/rest/XMark</nowiki></code>
+
* A new database with the name <b>XMark</b> is created. If XML input is sent in the HTTP body, the resulting database resource will be called <b>XMark.xml</b>:<br/><code><nowiki>http://localhost:8080/rest/XMark</nowiki></code>
* A new database is created, and no whitespaces will be removed from the passed on XML input:<br/><code><nowiki>http://localhost:8984/rest/XMark?chop=false</nowiki></code>
+
* A new database is created, and no whitespaces will be removed from the passed on XML input:<br/><code><nowiki>http://localhost:8080/rest/XMark?chop=false</nowiki></code>
* The contents of the HTTP body will be taken as input for the document <b>one.xml</b>, which will be stored in the <b>XMark</b> database:<br/><code><nowiki>http://localhost:8984/rest/XMark/one.xml</nowiki></code>
+
* The contents of the HTTP body will be taken as input for the document <b>one.xml</b>, which will be stored in the <b>XMark</b> database:<br/><code><nowiki>http://localhost:8080/rest/XMark/one.xml</nowiki></code>
  
An HTTP response with status code <code>201</code> (CREATED)
+
An HTTP response with status code <code>201</code> (CREATED) is sent back if the operation was successful. Otherwise, the server will reply with <code>404</code> (if a specified database was not found) or <code>400</code> (if the operation could not be completed).
is sent back if the operation was successful. Otherwise,
 
the server will reply with <code>404</code> (if a specified
 
database was not found) or <code>400</code> (if the operation
 
could not be completed).
 
  
Have a look at the [[REST#Usage Examples|usage examples]] for more detailed examples using Java and shell tools like cURL.
+
Take a look at the [[REST#Usage Examples|usage examples]] for more detailed examples using Java and shell tools like cURL.
  
 
==DELETE Method==
 
==DELETE Method==
Line 162: Line 206:
 
The DELETE method is used to delete databases or resources within a database.
 
The DELETE method is used to delete databases or resources within a database.
  
; Example
+
; Examples
* The <b>factbook</b> database is deleted:<br/><code><nowiki>http://localhost:8984/rest/factbook</nowiki></code>
+
* The <b>factbook</b> database is deleted:<br/><code><nowiki>http://localhost:8080/rest/factbook</nowiki></code>
* All resources of the <b>XMark</b> database are deleted that reside in the <b>tmp</b> path:<br/><code><nowiki>http://localhost:8984/rest/XMark/tmp/</nowiki></code>
+
* All resources of the <b>XMark</b> database are deleted that reside in the <b>tmp</b> path:<br/><code><nowiki>http://localhost:8080/rest/XMark/tmp/</nowiki></code>
 
   
 
   
 
The HTTP status code <code>404</code> is returned if no database is specified.
 
The HTTP status code <code>404</code> is returned if no database is specified.
Line 173: Line 217:
 
==GET Method==
 
==GET Method==
  
All query parameters that have not been processed before will be treated as variable assignments:
+
Query parameters that have not been processed otherwise will be treated as variable assignments:
  
 
; Example
 
; Example
  
* The following request assigns two variables to a server-side query file <code>mult.xq</code> placed in the HTTP directory:<br/><code>http://localhost:8984/rest?run=mult.xq&$a=21&$b=2</code>
+
The request <code>http://localhost:8080/rest?run=multiply&a=21&b=2</code> assigns two variables and invokes <code>multiply.xq</code>:
<pre class="brush:xquery">
+
<pre lang='xquery'>
(: XQuery file: mult.xq :)
+
(: XQuery file: multiply.xq :)
 
declare variable $a as xs:integer external;
 
declare variable $a as xs:integer external;
 
declare variable $b as xs:integer external;
 
declare variable $b as xs:integer external;
 
<mult>{ $a * $b }</mult>
 
<mult>{ $a * $b }</mult>
 +
</pre>
 +
 +
; Example
 +
 +
{{Announce|Updated with Version 11:}} Support for multiple values.
 +
 +
The request <code>http://localhost:8080/rest?run=sum&n=3&n=4&n=5</code> assigns multiple values to the same variable:
 +
<pre lang='xquery'>
 +
(: XQuery file: sum.xq :)
 +
declare variable $n as xs:integer* external;
 +
sum($n)
 
</pre>
 
</pre>
  
Line 189: Line 244:
 
==POST Method==
 
==POST Method==
  
If <code>query</code> or <code>run</code> is used as operation, external variables can be specified via the <code><variable/></code> element:
+
If <code>query</code> or <code>run</code> is used as an operation, external variables can be specified via the <code><variable/></code> element:
  
<pre class="brush:xml">
+
<pre lang="xml">
 
<query xmlns="http://basex.org/rest">
 
<query xmlns="http://basex.org/rest">
 
   <text><![CDATA[
 
   <text><![CDATA[
     declare variable $x as xs:integer external;
+
     declare variable $a as xs:integer external;
     declare variable $y as xs:integer external;
+
     declare variable $b as xs:integer external;
 
     <mult>{ $a * $b }</mult>
 
     <mult>{ $a * $b }</mult>
 
   ]]></text>
 
   ]]></text>
Line 211: Line 266:
 
# If the serialization parameter <code>[[Serialization|media-type]]</code> is supplied, it will be adopted as content-type.
 
# If the serialization parameter <code>[[Serialization|media-type]]</code> is supplied, it will be adopted as content-type.
 
# Otherwise, if the serialization parameter <code>[[Serialization|method]]</code> is supplied, the content-type will be chosen according to the following mapping:
 
# Otherwise, if the serialization parameter <code>[[Serialization|method]]</code> is supplied, the content-type will be chosen according to the following mapping:
#* <code>xml</code> → <code>application/xml</code>
+
#* <code>xml</code>, <code>adaptive</code>, <code>basex</code> → <code>application/xml</code>
 
#* <code>xhtml</code> → <code>text/html</code>
 
#* <code>xhtml</code> → <code>text/html</code>
 
#* <code>html</code> → <code>text/html</code>
 
#* <code>html</code> → <code>text/html</code>
 
#* <code>text</code> → <code>text/plain</code>
 
#* <code>text</code> → <code>text/plain</code>
 
#* <code>json</code> → <code>application/json</code>
 
#* <code>json</code> → <code>application/json</code>
#* <code>raw</code> → <code>application/octet-stream</code> (binary data will be sent in its original byte representation, i. e., without further conversion)
 
 
# If no media-type or serialization method is supplied, the content type of a response depends on the chosen REST operation:
 
# If no media-type or serialization method is supplied, the content type of a response depends on the chosen REST operation:
 
#* '''Query'''/'''Run''' → <code>application/xml</code>
 
#* '''Query'''/'''Run''' → <code>application/xml</code>
Line 226: Line 280:
 
The following three example requests all return <code>&lt;a/&gt;</code> with <code>application/xml</code> as content-type:
 
The following three example requests all return <code>&lt;a/&gt;</code> with <code>application/xml</code> as content-type:
  
:<code>http://localhost:8984/rest?query=%3Ca/%3E</code><br/><code>http://localhost:8984/rest?query=%3Ca/%3E&method=xml</code><br/><code>http://localhost:8984/rest?query=%3Ca/%3E&media-type=application/xml</code>
+
:<code>http://localhost:8080/rest?query=%3Ca/%3E</code><br/><code>http://localhost:8080/rest?query=%3Ca/%3E&method=xml</code><br/><code>http://localhost:8080/rest?query=%3Ca/%3E&media-type=application/xml</code>
  
 
=Usage Examples=
 
=Usage Examples=
Line 244: Line 298:
 
<code>org.basex.util.Base64</code> can be used for that purpose:
 
<code>org.basex.util.Base64</code> can be used for that purpose:
  
<pre class="brush:java">
+
<pre lang="java">
 
import java.net.*;
 
import java.net.*;
 
import org.basex.util.*;
 
import org.basex.util.*;
Line 251: Line 305:
 
   public static void main(String[] args) throws Exception {
 
   public static void main(String[] args) throws Exception {
 
     // The java URL connection to the resource.  
 
     // The java URL connection to the resource.  
     URL url = new URL("http://localhost:8984/rest/factbook");  
+
     URL url = new URL("http://localhost:8080/rest/factbook");  
 
        
 
        
 
     // Establish the connection to the URL.  
 
     // Establish the connection to the URL.  
Line 261: Line 315:
 
     String user = "bob";
 
     String user = "bob";
 
     String pw ="alice";
 
     String pw ="alice";
     // Encode user name and password pair with a base64 implementation.
+
     // Encode username and password pair with a base64 implementation.
 
     String encoded = Base64.encode(user + ":" + pw);
 
     String encoded = Base64.encode(user + ":" + pw);
 
     // Basic access authentication header to connection request.
 
     // Basic access authentication header to connection request.
Line 280: Line 334:
 
the connection (in this example we explicitly store the input file as raw):
 
the connection (in this example we explicitly store the input file as raw):
  
<pre class="brush:java">
+
<pre lang="java">
 
// store input as raw
 
// store input as raw
 
conn.setRequestProperty("Content-Type", "application/octet-stream");
 
conn.setRequestProperty("Content-Type", "application/octet-stream");
Line 292: Line 346:
 
==Command Line==  
 
==Command Line==  
  
Tools such as the Linux commands [http://www.gnu.org/s/wget/ Wget] or [http://curl.haxx.se/ cURL] exist to
+
Tools such as the Linux commands [https://www.gnu.org/s/wget/ Wget] or [http://curl.haxx.se/ cURL] exist to
 
perform HTTP requests (try copy &amp; paste):
 
perform HTTP requests (try copy &amp; paste):
  
 
;GET  
 
;GET  
* <code><nowiki>curl -i "http://localhost:8984/rest/factbook?query=//city/name"</nowiki></code>
+
* <code><nowiki>curl -i "http://localhost:8080/rest/factbook?query=//city/name"</nowiki></code>
 
;POST
 
;POST
* <code><nowiki>curl -i -X POST -H "Content-Type: application/xml" -d "&lt;query xmlns='http://basex.org/rest'&gt;&lt;text&gt;//city/name&lt;/text&gt;&lt;/query&gt;" "http://localhost:8984/rest/factbook"</nowiki></code>
+
* <code><nowiki>curl -i -X POST -H "Content-Type: application/xml" -d "&lt;query xmlns='http://basex.org/rest'&gt;&lt;text&gt;//city/name&lt;/text&gt;&lt;/query&gt;" "http://localhost:8080/rest/factbook"</nowiki></code>
* <code><nowiki>curl -i -X POST -H "Content-Type: application/xml" -T query.xml "http://localhost:8984/rest/factbook"</nowiki></code>  
+
* <code><nowiki>curl -i -X POST -H "Content-Type: application/xml" -T query.xml "http://localhost:8080/rest/factbook"</nowiki></code>  
 
;PUT
 
;PUT
* <code><nowiki>curl -i -X PUT -T "etc/xml/factbook.xml" "http://localhost:8984/rest/factbook"</nowiki></code>
+
* <code><nowiki>curl -i -X PUT -T "etc/xml/factbook.xml" "http://localhost:8080/rest/factbook"</nowiki></code>
* <code><nowiki>curl -i -X PUT -H "Content-Type: application/json" -T "plain.json" "http://localhost:8984/rest/plain"</nowiki></code>
+
* <code><nowiki>curl -i -X PUT -H "Content-Type: application/json" -T "plain.json" "http://localhost:8080/rest/plain"</nowiki></code>
 
;DELETE
 
;DELETE
* <code><nowiki>curl -i -X DELETE "http://admin:admin@localhost:8984/rest/factbook"</nowiki></code>
+
* <code><nowiki>curl -i -X DELETE "http://admin:admin@localhost:8080/rest/factbook"</nowiki></code>
  
 
=Changelog=
 
=Changelog=
 +
 +
;Version 11.0
 +
* Updated: [[#Request|Request]]: The extensions {{Code|.xq}} and {{Code|.bxs}} are successively attached to the supplied filename.
 +
* Updated: [[#Assigning Variables|Assigning Variables]]: Support for multiple values.
 +
 +
;Version 10.0
 +
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[[Category:Server]]
 
[[Category:HTTP]]
 
[[Category:Developer]]
 

Latest revision as of 17:38, 1 December 2023

This page presents one of the Web Application services. It describes how to use the REST API of BaseX.

BaseX offers a RESTful API for accessing database resources via URLs. REST (REpresentational State Transfer) facilitates a simple and fast access to databases through HTTP. The HTTP methods GET, PUT, DELETE, and POST can be used to interact with the database.

Usage[edit]

By default, REST services are available at http://localhost:8080/rest/. If no default credentials are specified in the URL or when starting the web application, they will be requested by the client (see further).

A web browser can be used to perform simple GET-based REST requests and display the response. Some alternatives for using REST are listed in the Usage Examples.

Since BaseX 10, results in the rest namespace are returned unprefixed:

<!-- before -->
<rest:databases xmlns:rest="http://basex.org/rest"/>

<!-- before -->
<databases xmlns="http://basex.org/rest"/>

URL Architecture[edit]

A request to the root URL returns all available databases:

http://localhost:8080/rest
<databases xmlns="http://basex.org/rest">
  <database resources="25742" size="43813599">articles</database>
  ...
</databases>

The resources of a database (directories, resource metadata) are listed if a database and an optional directory path is specified:

http://localhost:8080/rest/articles
<database name="articles" xmlns="http://basex.org/rest">
  <dir>binaries</dir>
  <resource type="xml" content-type="application/xml" size="77192">1973-02-08-xltp325.xml</resource>
  ...
</database>

If the path to a single resource is specified, the resource itself will be returned:

http://localhost:8080/rest/articles/1973-02-08-xltp325.xml

Parameters[edit]

The following parameters can be applied to the operations:

  • Variables:
    External variables can be bound before a query is evaluated (see below for more).
  • Context:
    The context parameter may be used to provide an initial XML context node.
  • Options:
    Specified Options are applied before the actual operation will be performed.
  • Serialization:
    All Serialization parameters known to BaseX can be specified as query parameters. Parameters that are specified within a query will be interpreted by the REST server before the output is generated.

While Options can be specified for all operations, the remaining parameters will only make sense for Query and Run.

Request[edit]

GET Method[edit]

If the GET method is used, all query parameters are directly specified within the URL. Additionally, the following operations can be specified:

  • query: Evaluate an XQuery expression. If a database or database path is specified in the URL, it is set as query context.
  • command: Execute a single database command.
  • run: Evaluate an XQuery file or command script located on the server. The file path is resolved against the RESTPATH directory. Similar to query, a database or database path is set as context. With Version 11, if no file is found and if the file suffix has been omitted, the extensions .xq and .bxs are successively attached to the supplied filename.
Examples

POST Method[edit]

The body of a POST request is interpreted as XML fragment, which specifies the operation to perform. The name of the root element determines how the body will be evaluated:

  • commands: Run Command Script
  • query: Execute XQuery expression
  • run: Run server-side file (query or command script)
  • command: Execute single command

The root element may be bound to the optional REST namespace. Existing command scripts can be sent to the server without any modifications.

For the other commands, the following child elements are supported:

Name Description
text Required; contains the query string, command string, or file to be run
parameter Serialization parameter (with @name and @value attributes)
option Database option (with @name and @value attributes)
variable Variable bindings
context Initial context item
Examples

Create an empty database and return database information:

<commands>
  <create-db name='db'/>
  <info-db/>
</commands>

Return the first five city names of the factbook database:

<rest xmlns="http://basex.org/rest">
  <rest><![CDATA[ (//city/name)[position() <= 5] ]]></text>
</rest>

Return string lengths of all text nodes that are found in the node that has been specified as initial context node:

<query>
  <text>for $i in .//text() return string-length($i)</text>
  <context>
    <xml>
      <text>Hello</text>
      <text>World</text>
    </xml>
  </context>
</query>

Return the registered database users encoded in ISO-8859-1:

<command>
  <text>show users</text>
  <parameter name='encoding' value='ISO-8859-1'/>
</command>

Create a new database from the specified input and preserve all whitespaces:

<command>
  <text>create db test http://files.basex.org/xml/xmark.xml</text>
  <option name='chop' value='false'/>
</command>

Bind value to the $person variable and run query find-person.xq:

<run>
  <variable name='person' value='Johannes Müller'/>
  <text>find-person.xq</text>
</run>

PUT Method[edit]

The PUT method is used to create new databases, or to add or update existing database resources:

  • Create Database:
    A new database is created if the URL only specifies the name of a database. If the request body contains XML, a single document is created, adopting the name of the database.
  • Store Resource:
    A resource is added to the database if the URL contains a database path. If the addressed resource already exists, it is replaced by the new input.

There are two ways to store non-XML data in BaseX:

  • Store as Raw Data:
    If application/octet-stream is chosen as content-type, the input is added as Binary Data.
  • Convert to XML:
    Incoming data is converted to XML if a parser is available for the specified content-type. The following content types are supported:
    • application/json: Stores JSON as XML.
    • text/plain: Stores plain text input as XML.
    • text/comma-separated-values: Stores CSV text input as XML.
    • text/html: Stores HTML input as XML.

Conversion can be influenced by specifying additional content-type parameters (see RESTXQ for more information).

If raw data is added and if no content type, or a wrong content, is specified, a 400 (BAD REQUEST) error will be raised.

Examples
  • A new database with the name XMark is created. If XML input is sent in the HTTP body, the resulting database resource will be called XMark.xml:
    http://localhost:8080/rest/XMark
  • A new database is created, and no whitespaces will be removed from the passed on XML input:
    http://localhost:8080/rest/XMark?chop=false
  • The contents of the HTTP body will be taken as input for the document one.xml, which will be stored in the XMark database:
    http://localhost:8080/rest/XMark/one.xml

An HTTP response with status code 201 (CREATED) is sent back if the operation was successful. Otherwise, the server will reply with 404 (if a specified database was not found) or 400 (if the operation could not be completed).

Take a look at the usage examples for more detailed examples using Java and shell tools like cURL.

DELETE Method[edit]

The DELETE method is used to delete databases or resources within a database.

Examples
  • The factbook database is deleted:
    http://localhost:8080/rest/factbook
  • All resources of the XMark database are deleted that reside in the tmp path:
    http://localhost:8080/rest/XMark/tmp/

The HTTP status code 404 is returned if no database is specified. 200 (OK) will be sent in all other cases.

Assigning Variables[edit]

GET Method[edit]

Query parameters that have not been processed otherwise will be treated as variable assignments:

Example

The request http://localhost:8080/rest?run=multiply&a=21&b=2 assigns two variables and invokes multiply.xq:

(: XQuery file: multiply.xq :)
declare variable $a as xs:integer external;
declare variable $b as xs:integer external;
<mult>{ $a * $b }</mult>
Example

Updated with Version 11: Support for multiple values.

The request http://localhost:8080/rest?run=sum&n=3&n=4&n=5 assigns multiple values to the same variable:

(: XQuery file: sum.xq :)
declare variable $n as xs:integer* external;
sum($n)

The dollar sign can be omitted as long as the variable name does not equal a parameter keyword (e.g.: method).

POST Method[edit]

If query or run is used as an operation, external variables can be specified via the <variable/> element:

<query xmlns="http://basex.org/rest">
  <text><![CDATA[
    declare variable $a as xs:integer external;
    declare variable $b as xs:integer external;
    <mult>{ $a * $b }</mult>
  ]]></text>
  <variable name="a" value="21"/>
  <variable name="b" value="2"/>
</query>

Response[edit]

Content Type[edit]

As the content type of a REST response cannot necessarily be dynamically determined, it can be enforced by the user. The final content type of a REST response is chosen as follows:

  1. If the serialization parameter media-type is supplied, it will be adopted as content-type.
  2. Otherwise, if the serialization parameter method is supplied, the content-type will be chosen according to the following mapping:
    • xml, adaptive, basexapplication/xml
    • xhtmltext/html
    • htmltext/html
    • texttext/plain
    • jsonapplication/json
  3. If no media-type or serialization method is supplied, the content type of a response depends on the chosen REST operation:
    • Query/Runapplication/xml
    • Commandtext/plain
    • Getapplication/xml, or content type of the addressed resource

Serialization parameters can either be supplied as query parameters or within the query.

The following three example requests all return <a/> with application/xml as content-type:

http://localhost:8080/rest?query=%3Ca/%3E
http://localhost:8080/rest?query=%3Ca/%3E&method=xml
http://localhost:8080/rest?query=%3Ca/%3E&media-type=application/xml

Usage Examples[edit]

Java[edit]

Authentication[edit]

Most programming languages offer libraries to communicate with HTTP servers. The following example demonstrates how easy it is to perform a DELETE request with Java.

Basic access authentication can be activated in Java by adding an authorization header to the HttpURLConnection instance. The header contains the word Basic, which specifies the authentication method, followed by the Base64-encoded USER:PASSWORD pair. As Java does not include a default conversion library for Base64 data, the internal BaseX class org.basex.util.Base64 can be used for that purpose:

import java.net.*;
import org.basex.util.*;

public final class RESTExample {
  public static void main(String[] args) throws Exception {
    // The java URL connection to the resource. 
    URL url = new URL("http://localhost:8080/rest/factbook"); 
      
    // Establish the connection to the URL. 
    HttpURLConnection conn = (HttpURLConnection) url.openConnection(); 
    // Set as DELETE request. 
    conn.setRequestMethod("DELETE"); 
     
    // User and password.
    String user = "bob";
    String pw ="alice";
    // Encode username and password pair with a base64 implementation.
    String encoded = Base64.encode(user + ":" + pw);
    // Basic access authentication header to connection request.
    conn.setRequestProperty("Authorization", "Basic " + encoded);
      
    // Print the HTTP response code. 
    System.out.println("HTTP response: " + conn.getResponseCode()); 
      
    // Close connection. 
    conn.disconnect(); 
  }
}

Content-Types[edit]

The content-type of the input can easily be included, just add the following property to the connection (in this example we explicitly store the input file as raw):

// store input as raw
conn.setRequestProperty("Content-Type", "application/octet-stream");

See the PUT Requests section for a description of the possible content-types.

Find Java examples for all methods here: GET, POST, PUT, DELETE.

Command Line[edit]

Tools such as the Linux commands Wget or cURL exist to perform HTTP requests (try copy & paste):

GET
  • curl -i "http://localhost:8080/rest/factbook?query=//city/name"
POST
  • curl -i -X POST -H "Content-Type: application/xml" -d "<query xmlns='http://basex.org/rest'><text>//city/name</text></query>" "http://localhost:8080/rest/factbook"
  • curl -i -X POST -H "Content-Type: application/xml" -T query.xml "http://localhost:8080/rest/factbook"
PUT
  • curl -i -X PUT -T "etc/xml/factbook.xml" "http://localhost:8080/rest/factbook"
  • curl -i -X PUT -H "Content-Type: application/json" -T "plain.json" "http://localhost:8080/rest/plain"
DELETE
  • curl -i -X DELETE "http://admin:admin@localhost:8080/rest/factbook"

Changelog[edit]

Version 11.0
  • Updated: Request: The extensions .xq and .bxs are successively attached to the supplied filename.
  • Updated: Assigning Variables: Support for multiple values.
Version 10.0
  • Updated: Results in the rest namespace will be returned unprefixed.
  • Updated: dir elements are returned when listing the contents of a database.
Version 9.0
  • Added: Support for command scripts in the POST Method.
  • Updated: The REST namespace in the POST Method has become optional.
Version 8.1
  • Added: Support for input-specific content-type parameters
  • Updated: The run operation now resolves file paths against the RESTPATH option.
Version 8.0
  • Removed: wrap parameter
Version 7.9
  • Updated: Also evaluate command scripts via the run operation.
Version 7.2
  • Removed: Direct evaluation of adresses resources with application/xquery as content type
Version 7.1.1
  • Added: options parameter for specifying database options
Version 7.1
  • Added: PUT request: automatic conversion to XML if known content type is specified
Version 7.0
  • REST API introduced, replacing the old JAX-RX API