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* Create an empty database and return database information: <pre lang="xml"><commands> <create-db name='db'/> <info-db/></commands></pre> Return the first five city names of the <b>factbook</b> database: <syntaxhighlight pre lang="xml">
* Return string lengths of all text nodes that are found in the node that has been specified as initial context node: <syntaxhighlight pre lang="xml">
* Return the registered database users encoded in <code>ISO-8859-1</code>: <syntaxhighlight pre lang="xml">
* Create a new database from the specified input and preserve all whitespaces: <syntaxhighlight pre lang="xml">
* Bind value to the {{Code|$person}} variable and run query <code>find-person.xq</code>: <syntaxhighlight pre lang="xml">
Have Take a look at the [[REST#Usage Examples|usage examples]] for more detailed examples using Java and shell tools like cURL.
no edit summary
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 ([https://en.wikipedia.org/wiki/Representational_State_Transfer REpresentational State Transfer])facilitates a simple and fast access to databases through HTTP. The HTTP methodsGET, PUT, DELETE, and POST can be used to interact with the database.
=Usage=
Since BaseX 10, results in the {{Code|rest}} namespace are returned unprefixed:
<syntaxhighlight pre lang="xml">
<!-- before -->
<rest:databases xmlns:rest="http://basex.org/rest"/>
<!-- before BaseX 10 -->
<databases xmlns="http://basex.org/rest"/>
</syntaxhighlightpre>
=URL Architecture=
:<code>http://localhost:8080/rest</code>
<syntaxhighlight pre lang="xml">
<databases xmlns="http://basex.org/rest">
<database resources="25742" size="43813599">articles</database>
...
</databases>
</syntaxhighlightpre>
The resources of a database (directories, resource metadata) are listed if a database and an optional directory path is specified:
:<code>http://localhost:8080/rest/articles</code>
<syntaxhighlight pre lang="xml">
<database name="articles" xmlns="http://basex.org/rest">
<dir>binaries</dir>
...
</database>
</syntaxhighlightpre>
If the path to a single resource is specified, the resource itself will be returned:
==GET Method==
If the GET method is used, all query parameters are directly specified within the URL.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 set as query context.
* {{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 {{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
* 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 JSONMLJsonML:<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.xq&encoding=US-ASCII</code> * The next URL lists all database users that who are known to BaseX:<br/><code>http://localhost:8080/rest?command=show+users</code>
==POST Method==
* {{Code|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: * Create an empty database and return database information: <syntaxhighlight lang="xml"><commands> <create-db name='db'/> <info-db/></commands></syntaxhighlight>.
For the other commands, the following child elements are supported:
; Examples
<rest xmlns="http://basex.org/rest">
<rest><![CDATA[ (//city/name)[position() <= 5] ]]></text>
</rest>
</syntaxhighlightpre>
<query>
<text>for $i in .//text() return string-length($i)</text>
</context>
</query>
</syntaxhighlightpre>
<command>
<text>show users</text>
<parameter name='encoding' value='ISO-8859-1'/>
</command>
</syntaxhighlightpre>
<command>
<text>create db test http://files.basex.org/xml/xmark.xml</text>
<option name='chop' value='false'/>
</command>
</syntaxhighlightpre>
<run>
<variable name='person' value='Johannes Müller'/>
<text>find-person.xq</text>
</run>
</syntaxhighlightpre>
==PUT Method==
* 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)is sent back if the operation was successful. Otherwise,the server will reply with <code>404</code> (if a specifieddatabase was not found) or <code>400</code> (if the operationcould not be completed).
==DELETE Method==
The DELETE method is used to delete databases or resources within a database.
; ExampleExamples
* 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:8080/rest/XMark/tmp/</nowiki></code>
; Example
The request <code>http://localhost:8080/rest?run=multiply.xq&a=21&b=2</code> assigns two variables and invokes <code>multiply.xq</code>:<syntaxhighlight pre lang="'xquery"'>
(: XQuery file: multiply.xq :)
declare variable $a as xs:integer external;
declare variable $b as xs:integer external;
<mult>{ $a * $b }</mult>
</syntaxhighlightpre>
; Example
{{Announce|Updated with Version 11:}} Support for multiple values.
The request <code>http://localhost:8080/rest?run=sum.xq&n=3&n=4&n=5</code> assigns multiple values to the same variable:<syntaxhighlight pre lang="'xquery"'>
(: XQuery file: sum.xq :)
declare variable $n as xs:integer* external;
sum($n)
</syntaxhighlightpre>
The dollar sign can be omitted as long as the variable name does not equal a parameter keyword (e.g.: <code>method</code>).
If <code>query</code> or <code>run</code> is used as an operation, external variables can be specified via the <code><variable/></code> element:
<syntaxhighlight pre lang="xml">
<query xmlns="http://basex.org/rest">
<text><![CDATA[
<variable name="b" value="2"/>
</query>
</syntaxhighlightpre>
=Response=
<code>org.basex.util.Base64</code> can be used for that purpose:
<syntaxhighlight pre lang="java">
import java.net.*;
import org.basex.util.*;
}
}
</syntaxhighlightpre>
===Content-Types===
the connection (in this example we explicitly store the input file as raw):
<syntaxhighlight pre lang="java">
// store input as raw
conn.setRequestProperty("Content-Type", "application/octet-stream");
</syntaxhighlightpre>
See the [[REST#PUT Requests|PUT Requests]] section for a description of the possible content-types.
;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.
