SherbyNet - /page/wikibook/entry.mu

Micron Document

<!DOCTYPE html>

<title>Web Feature Service</title>

</head>

<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Web Feature Service</span></span>

</h1>

</header>

<p>In <a href="Computing" title="Computing">computing</a>, the <a href="Open_Geospatial_Consortium" title="Open Geospatial Consortium">Open Geospatial Consortium</a> <b>Web Feature Service</b> (<b>WFS</b>) Interface Standard provides an <a href="Interface_(computer_science)" class="mw-redirect" title="Interface (computer science)">interface</a> allowing requests for <a href="Geography" title="Geography">geographical</a> features across the <a href="World_Wide_Web" title="World Wide Web">web</a> using platform-independent calls. One can think of geographical features as the "<a href="Source_code" title="Source code">source code</a>" behind a map, whereas the <a href="Web_Map_Service" title="Web Map Service">WMS</a> interface or online <a href="Tiled_web_map" title="Tiled web map">tiled mapping</a> portals like <a href="Google_Maps" title="Google Maps">Google Maps</a> return only an image, which end-users cannot edit or <a href="Geographic_information_system#Spatial_analysis_with_GIS" title="Geographic information system">spatially analyze</a>. The <a href="XML" title="XML">XML</a>-based <a href="Geography_Markup_Language" title="Geography Markup Language">Geography Markup Language</a> (GML) furnishes the default payload-encoding for transporting geographic features, but other formats like <a href="Shapefile" title="Shapefile">shapefiles</a> can also serve for transport. In early 2006 the <a href="Open_Geospatial_Consortium" title="Open Geospatial Consortium">OGC</a> members approved the OpenGIS GML Simple Features Profile.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> This profile is designed both to increase interoperability between WFS servers and to improve the ease of implementation of the WFS standard.

</p><p>The OGC membership defined and maintains the WFS specification. Numerous commercial and <a href="Open-source_software" title="Open-source software">open-source</a> implementations of the WFS interface standard exist, including the open-source reference implementations <a href="GeoServer" title="GeoServer">GeoServer</a> and <a href="Deegree" class="mw-redirect" title="Deegree">deegree</a>. The OGC Implementing Products page<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>

provides a comprehensive list of WFS implementations.

</p>

<div class="mw-heading mw-heading2"><h2 id="Overview">Overview</h2></div>

<p>The WFS specification defines interfaces for describing data manipulation operations of geographic features. Data manipulation operations include the ability to:

</p>

<ul><li>get or query features based on spatial and non-spatial constraints</li>

<li>create a new feature instance</li>

<li>delete a feature instance</li>

<li>update a feature instance</li></ul>

<p>The basic Web Feature Service allows querying and retrieval of features. A transactional Web Feature Service (WFS-T) allows creation, deletion, and updating of features.

</p><p>A WFS describes discovery, query, or data transformation operations. The client generates the request and posts it to a web feature server using HTTP. The web feature server then executes the request. The WFS specification uses HTTP as the distributed computing platform, although this is not a hard requirement.

</p><p>There are two encodings defined for WFS operations:

</p>

<ul><li><a href="XML" title="XML">XML</a> (amenable to HTTP POST, or <a href="SOAP" title="SOAP">SOAP</a>)</li>

<li>Key/value pairs (encoded in HTTP GET <a href="Query_string" title="Query string">query strings</a>, to perform <a href="Remote_procedure_call" title="Remote procedure call">remote procedure calls</a>)<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup></li></ul>

<p>In the taxonomy of <a href="Web_Services" class="mw-redirect" title="Web Services">Web Services</a>, WFS is best categorized as a non-RESTful RPC type service.

</p>

<div class="mw-heading mw-heading3"><h3 id="Communication_models">Communication models</h3></div>

<p>The WFS Web Feature Services or Web Feature Server specification supports two communication models:

</p>

<ul><li>Stateless Request Reply</li>

<dl><dd><dl><dd>A messaging system in which clients address messages to a specific node in a content hierarchy, called a topic. Publishers and subscribers are generally anonymous and can dynamically publish or subscribe to the content hierarchy. The system takes care of distributing the messages arriving from a node's multiple publishers to its multiple subscribers. Messages are generally not persistent and will only be received by subscribers who are listening at the time the message is sent. A special case known as a “durable subscription” allows subscribers to receive messages sent while the subscribers are not active. (Source: <a rel="nofollow" class="external text" href="http://java.sun.com/j2ee/1.4/docs/glossary.html">Oracle Technology Network for Java Developers | Oracle Technology Network | Oracle</a>)</dd></dl></dd></dl>

<p>The Web Notification Service (WNS) is one of the implementation specifications for the Pub/Sub model. Regardless of the model, <a href="Uniform_Resource_Locator" class="mw-redirect" title="Uniform Resource Locator">URL</a> format is used and specified in the WFS specification. At this time there are no open-standard implementations of WNSs. Vendors plan to release implementations once the standard has been ratified.

</p>

/* start https://en.wikipedia.org/ */

.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}

/* end https://en.wikipedia.org/ */

</style><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="Geography_Markup_Language" title="Geography Markup Language">Geography Markup Language</a></div>

<p>Data passed between a Web Feature Server and a client is encoded with <a href="Geography_Markup_Language" title="Geography Markup Language">Geography Markup Language</a> (GML), an XML dialect which can be used to model geographic features.

</p><p>The 1.0.0 version of the WFS specification requires the use of GML version 2.1.2, while the 1.1.0 version of the WFS specification requires the use of GML version 3.1.1. For both versions of the WFS specification, an arbitrary number of other encodings can also be defined, in addition to the required GML 2.1.2 or 3.1.1 format (for 1.0.0 and 1.1.0 respectively).

</p><p>GML 2.1.2 contains encoding support for basic geometric 'primitives': points, lines, polygons, etc.

</p><p>GML 3.1.1 contains encoding support for more advanced geometric representations: curves, surfaces, multi-dimensions (time, elevation, multi-band imagery). In addition, GML 3.1.1 includes encoding support for topologically integrated datasets.

</p>

<div class="mw-heading mw-heading2"><h2 id="Public_Interfaces">Public Interfaces</h2></div>

<div class="mw-heading mw-heading3"><h3 id="Static_Interfaces">Static Interfaces</h3></div>

<p>The static interface model for the <a href="Open_Geospatial_Consortium" title="Open Geospatial Consortium">OGC</a> Web Service model appears in the figure below.

The Transaction and LockFeature operations are also optional.

</p><p>When writing a WFS, you must implement the following operations:

</p>

<ul><li>GetCapabilities - this queries the WFS service to determine available options.</li>

<li>DescribeFeatureType - this retrieves the XML schema to allow the WFS client to parse the resultsets.</li>

<li>GetFeature - this performs the actual query - parameters such as <a href="Bounding_box" class="mw-redirect" title="Bounding box">bounding box</a> and any other filters should be passed in, as appropriate, and the WFS service then returns a GML resultset containing full geometry and feature attributes.</li></ul>

<div class="mw-heading mw-heading3"><h3 id="Dynamic_interface_updates">Dynamic interface updates</h3></div>

<p>The client gets updates by one of two mechanisms:

</p>

<ul><li>Notification: Recommended but not mandatory. Depends on the availability of a WNS implementation.</li>

<li>Polling: Use this method if a WNS implementation is not available.</li></ul>

<p><b>WFS dynamic interface web notification model</b>

</p><p>This model uses the OGC Web Notification Service to send update notifications to registered clients.

</p>

<ul><li><a href="Open_Source_Geospatial_Foundation" title="Open Source Geospatial Foundation">Open Source Geospatial Foundation</a></li>

<li><a href="Web_Coverage_Service" title="Web Coverage Service">Web Coverage Service</a> (WCS)</li>

<li><a href="Web_Coverage_Processing_Service" title="Web Coverage Processing Service">Web Coverage Processing Service</a> (WCPS)</li>

<li><a href="Web_Map_Service" title="Web Map Service">Web Map Service</a> (WMS)</li></ul>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><a rel="nofollow" class="external text" href="http://www.opengeospatial.org/standards/wfs"><i>OpenGIS Web Feature Service (WFS) Implementation Specification</i></a></li>

<li><a rel="nofollow" class="external text" href="http://portal.opengeospatial.org/files/?artifact_id=8340"><i>Filter Encoding Specification</i></a></li>

<li><a rel="nofollow" class="external text" href="http://geoserver.org"><i>GeoServer Open Source Reference Implementation</i></a></li>

<li><a rel="nofollow" class="external text" href="http://www.deegree.org"><i>deegree Open Source Geospatial Web Services</i></a></li>

<li><a rel="nofollow" class="external text" href="http://www.weichand.de/2012/06/07/wfs-2-0-client-plugin-for-qgis-english/"><i>WFS 2.0 Client – Plugin for QGIS (english)</i></a></li>

<li><a rel="nofollow" class="external text" href="http://portal.opengeospatial.org/files/?artifact_id=18776"><i>WNS: Draft OpenGIS Web Notification Service Implementation Specification</i></a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}

/* end https://en.wikipedia.org/ */

</style><div class="reflist">

/* start https://en.wikipedia.org/ */

.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("./mw/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("./mw/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("./mw/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("./mw/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}

/* end https://en.wikipedia.org/ */

</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://portal.opengeospatial.org/files/?artifact_id=15201">"Geography Markup Language (GML) simple features profile"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2023-10-31</span></span>.</cite></span>

</li>

<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20190720203837/http://www.opengeospatial.org/resource/products/byspec/?specid=50">"Implementations by Specification | OGC"</a>. <i>www.opengeospatial.org</i>. Archived from <a rel="nofollow" class="external text" href="http://www.opengeospatial.org/resource/products/byspec/?specid=50">the original</a> on 2019-07-20<span class="reference-accessdate">. Retrieved <span class="nowrap">2014-07-02</span></span>.</cite></span>

</li>

<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://portal.opengeospatial.org/files/?artifact_id=36263&format=pdf">"WCS Extension -- KVP Protocol"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2023-10-31</span></span>.</cite></span>

</li>

</ol></div></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}

/* end https://en.wikipedia.org/ */

</style><style data-mw-deduplicate="TemplateStyles:r1236075235">

/* start https://en.wikipedia.org/ */

.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}

/* end https://en.wikipedia.org/ */

</style></div><div role="navigation" class="navbox" aria-labelledby="Standards_of_the_Open_Geospatial_Consortium_(OGC)53" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><style data-mw-deduplicate="TemplateStyles:r1239400231">

/* start https://en.wikipedia.org/ */

.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}

/* end https://en.wikipedia.org/ */

</style><div id="Standards_of_the_Open_Geospatial_Consortium_(OGC)53" style="font-size:114%;margin:0 4em">Standards of the <a href="Open_Geospatial_Consortium" title="Open Geospatial Consortium">Open Geospatial Consortium</a> (OGC)</div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="GeoPackage" title="GeoPackage">GeoPackage</a></li>

<li><a href="GeoRSS" title="GeoRSS">GeoRSS</a></li>

<li><a href="GeoSPARQL" title="GeoSPARQL">GeoSPARQL</a></li>

<li><a href="OGC_Reference_Model" title="OGC Reference Model">OGC Reference Model</a></li>

<li><a href="SensorML" title="SensorML">SensorML</a></li>

<li><a href="TransducerML" title="TransducerML">TransducerML</a></li>

<li><a href="WaterML" title="WaterML">WaterML</a></li>

</div></td></tr></tbody></table></div></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2025-02-03" href="https://en.wikipedia.org/wiki/?title=Web_Feature_Service&oldid=1273583996">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

</div>

</div></div>

</div>

</main>

</div>

</body></html>