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This [[Module Library|XQuery Module]] provides simple functions to fetch the content of resources identified by URIs. Resources can be stored locally or remotely and e.g. use the {{Code|file://}} or {{Code|http://}} scheme. If more control over HTTP requests is required, the [[HTTP Client Module]] can be used. With the [[HTML Module]], retrieved HTML documents can be converted to XML.

All functions and errors in this module are assigned to the <code><nowiki>http://basex.org/modules/fetch</nowiki></code> namespace, which is statically bound to the {{Code|fetch}} prefix.<br/>All errors are assigned URI arguments can point be URLs or point to local files. Relative file paths will be resolved against the <code><nowiki>http://basex.org/errors</nowiki></code> namespace''current working directory'' (for more details, which is statically bound to have a look at the {{Code[[File Module#File Paths|bxerr}} prefixFile Module]]).

|Fetches the resource referred to by the given URI and returns it as [[Streaming Lazy Module|streamablelazy]] {{Code|xs:base64Binary}}item.

|{{Error|BXFE0001open|XQuery Errors#Functions Errors}} the URI could not be resolved, or the resource could not be retrieved.

* <code><nowiki>streamlazy:materializecache(fetch:binary("http://en.wikipedia.org"))</nowiki></code> returns a materialized representation of enforces the streamable resultfetch operation (otherwise, it will be delayed until requested first).

|{{Func|fetch:text|$uri as xs:string|xs:string}}<br/>{{Func|fetch:text|$uri as xs:string, $encoding as xs:string|xs:string}}<br/>{{Func|fetch:text|$uri as xs:string, $encoding as xs:string, $fallback as xs:boolean|xs:string}}<br/>

|Fetches the resource referred to by the given URI {{Code|$uri}} and returns it as [[Streaming Lazy Module|streamablelazy]] {{Code|xs:string}}item:* The UTF-8 default encoding can be overwritten with the optional {{Code|$encoding}} argument.* By default, invalid characters will be rejected. If {{Code|$fallback}} is set to true, these characters will be replaced with the Unicode replacement character <code>FFFD</code> (&#xFFFD;).

|{{Error|BXFE0001open|XQuery Errors#Functions Errors}} the URI could not be resolved, or the resource could not be retrieved. Invalid XML characters will be ignored if the <code>[[Options#CHECKSTRINGS|CHECKSTRINGS]]</code> option is turned off.<br/>{{Error|BXFE0002encoding|XQuery Errors#Functions Errors}} the specified encoding is not supported, or unknown.

* <code><nowiki>streamfetch:text("http://www.bbc.com","US-ASCII",true())</nowiki></code> returns the BBC homepage in US-ASCII with all non-US-ASCII characters replaced with &#xFFFD;.* <code><nowiki>lazy:materializecache(fetch:text("http://en.wikipedia.org"))</nowiki></code> returns a materialized representation of enforces the streamable resultfetch operation (otherwise, it will be delayed until requested first).

|{{Func|fetch:xml|$uri as xs:string|document-node()}}<br/>{{Func|fetch:xml|$uri as xs:string, $options as map(xs:string, item()*)?|document-node()}}

|Fetches the resource referred to by the given {{Code|$uri}} and returns it as an XML document.<br/>In contrast to <code>fn:doc</code>, each function call returns a different document node. As a consequence, document instances created by this function will not be kept in memory until the end of query evaluation.<br/>The {{Code|$options}} argument can be used to change the parsing behavior. Allowed options are all [[Options#Parsing|parsing]] and [[Options#XML Parsing|XML parsing]] options in lower case.<br/>The function is different to <code>fn:doc</code> in various aspects:* As it is non-deterministic, a new document node will be created by each call of this function.* A document created by this function will be garbage-collected as soon as it is not referenced anymore.* URIs will not be resolved against existing databases. As a result, it will not trigger any locks (see [[Transaction Management#Limitations|limitations of database locking]] for more details).

|{{Error|BXFE0001open|XQuery Errors#Functions Errors}} the URI could not be resolved, or the resource could not be retrieved.|-| '''Examples'''|* Retrieve an XML representation of the English Wikipedia main HTML page, chop all whitespace nodes:<syntaxhighlight lang="xquery">fetch:xml("http://en.wikipedia.org", map { 'chop': true() })</syntaxhighlight>* Return a document located in the current base directory:<syntaxhighlight lang="xquery">fetch:xml(file:base-dir() || "example.xml")</syntaxhighlight>* Return a web page as XML, preserve namespaces:<syntaxhighlight lang="xquery">fetch:xml( 'http://basex.org/', map { 'parser': 'html', 'htmlparser': map { 'nons': false() } })</syntaxhighlight>|} ==fetch:xml-binary== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|fetch:xml-binary|$data as xs:base64Binary|document-node()}}<br/>{{Func|fetch:xml-binary|$data as xs:base64Binary, $options as map(*)?|document-node()}}|-| '''Summary'''|Parses binary {{Code|$data}} and returns it as document node.<br/>In contrast to fn:parse-xml, which expects an XQuery string, the input of this function can be arbitrarily encoded. The encoding will be derived from the XML declaration or (in case of UTF16 or UTF32) from the first bytes of the input.<br/>The {{Code|$options}} argument can be used to change the parsing behavior. Allowed options are all [[Options#Parsing|parsing]] and [[Options#XML Parsing|XML parsing]] options in lower case.

|* Retrieves file input as binary data and parses it as XML:<syntaxhighlight lang="xquery">fetch:xml-binary(file:read-binary('doc.xml'))</syntaxhighlight>* Encodes a string as CP1252 and parses it as XML. The following expression returns an XML representation input and the string {{Code|touché}} will be correctly decoded because of the English Wikipedia main HTML page and chops all whitespace nodesXML declaration:<pre classsyntaxhighlight lang="brush:xquery">fetch:xml-binary(convert:string-to-base64( "http:<?xml version='1.0' encoding='CP1252'?><xml>touché</xml>", "CP1252"))</ensyntaxhighlight>* Encodes a string as UTF16 and parses it as XML.wikipedia.orgThe document will be correctly decoded, as the first bytes of the data indicate that the input must be UTF16:<syntaxhighlight lang="xquery", map { 'chop'>fetch:xml-binary(convert: truestring-to-base64()"<xml/>", "UTF16"))</presyntaxhighlight>

|{{Error|BXFE0001open|XQuery Errors#Functions Errors}} the URI could not be resolved, or the resource could not be retrieved.

|{{Code|BXFE0001encoding}}|The specified encoding is not supported, or unknown.|-|{{Code|open}}