<map-feature>
Map features are real or imaginary location objects represented in 2D according to a standard model, called the Simple Features model. There exists a wide variety of formats that allow the encoding of the Simple Features model, famously including: GeoJSON, Keyhole Markup Language (KML), and shape files (.shp), among many others.
Map features are represented in HTML MapML using a <map-feature> element, which is rendered on the map through translation to SVG. This allows the feature to scale without distortion, as you zoom in and out.
A <map-feature> element is a container for a feature's accessible name (<map-featurecaption>), scalar properties (<map-properties>) and its geometry (<map-geometry>). The <map-feature> element can be modeled as inline HTML content as a child of the <layer-> element, or in an XHTML MapML document, as a child of the <map-body> element.
Attributes
zoom
- This allows you to set the zoom level the feature is rendered at. The zoom value should fall within the range of 0 to the maximum zoom level of the map's projection.
Child Elements
<map-featurecaption>
This element contains the feature's accessible name, which is displayed when the feature is in focus or hovered.
<map-properties>
This element contains the contents of the popup associated to a given feature. Details on the properties elements and it's syntax can be found here.
<map-geometry>
This element contains the different points, lines and polygons that will be drawn. Details on the geometry elements and it's syntax can be found here.
Attributes
cs- This allows you to set the coordinate system of geometries.
- Defaults to pcrs (projected coordinates), but can be set to tilematrix | pcrs | gcrs explicitly.
Related Elements
Other elements may be important to provide context for feature data:
<map-meta name="zoom">
Sets the native minimum and maximum native zoom. It also allows you to set a value, this is the default zoom of all features in the case the <map-feature> is missing a zoom attribute.
<map-meta name="zoom" content="min=1,max=5,value=0"></map-meta>
<map-meta name="projection">
Sets the projection of the layer.
<map-meta name="projection" content="CBMTILE"></map-meta>
<map-meta name="cs">
Sets the default coordinate system of the layer. If a feature is missing the cs attribute it will 'fall back' to the value provided by a map-meta element, or pcrs if no map-meta element is in scope.
<map-meta name="cs" content="gcrs"></map-meta>
<map-meta name="extent">
Sets the extent of the layer.
<map-meta name="extent" content="zoom=0,top-left-column=0,top-left-row=0,bottom-right-column=5,bottom-right-row=5"></map-meta>
Examples
<mapml-viewer projection="CBMTILE" zoom="2" lat="45.5052040" lon="-75.2202344"
controls>
<layer- label="Arizona" checked>
<map-meta name="projection" content="CBMTILE"></map-meta>
<map-meta name="zoom" content="min=1,max=5,value=0"></map-meta>
<map-meta name="cs" content="gcrs"></map-meta>
<map-meta name="extent" content="zoom=0,top-left-column=0,top-left-row=0,bottom-right-column=5,bottom-right-row=5"></map-meta>
<map-link id="first" rel="stylesheet" type="text/css" href="first.css"></map-link>
<map-feature zoom="2" class="refDiff">
<map-properties>
<h1>Test</h1>
<a href="https://example.org/">test</a>
</map-properties>
<map-geometry cs="tilematrix">
<map-polygon>
<map-coordinates>11 11 12 11 12 12 11 12</map-coordinates>
</map-polygon>
</map-geometry>
</map-feature>
<map-feature zoom="2" class="refDiff">
<map-properties>
<h1>Test</h1>
</map-properties>
<map-geometry cs="pcrs">
<map-polygon>
<map-coordinates>257421 -3567196 -271745 1221771 -3896544 242811 -3183549 -2613313</map-coordinates>
</map-polygon>
</map-geometry>
</map-feature>
<map-feature zoom="2" class="refDiff">
<map-properties>
<h1>Test</h1>
</map-properties>
<map-geometry cs="tcrs">
<map-polygon>
<map-coordinates>2771 3106 2946 3113 2954 3210 2815 3192</map-coordinates>
</map-polygon>
</map-geometry>
</map-feature>
<map-feature zoom="2" class="refDiff">
<map-properties>
<h1>Arizona</h1>
</map-properties>
<map-geometry>
<map-polygon>
<map-coordinates>-109.042503 37.000263 -109.04798 31.331629 -111.074448 31.331629 -112.246513 31.704061
-114.815198 32.492741 -114.72209 32.717295 -114.524921 32.755634 -114.470151 32.843265 -114.524921
33.029481 -114.661844 33.034958 -114.727567 33.40739 -114.524921 33.54979 -114.497536 33.697668
-114.535874 33.933176 -114.415382 34.108438 -114.256551 34.174162 -114.136058 34.305608 -114.333228
34.448009 -114.470151 34.710902 -114.634459 34.87521 -114.634459 35.00118 -114.574213 35.138103
-114.596121 35.324319 -114.678275 35.516012 -114.738521 36.102045 -114.371566 36.140383 -114.251074
36.01989 -114.152489 36.025367 -114.048427 36.195153 -114.048427 37.000263 -110.499369 37.00574
-109.042503 37.000263</map-coordinates>
</map-polygon>
</map-geometry>
</map-feature>
</layer->
</mapml-viewer>
An inline HTML map-feature
<layer- label="My Feature Layer" checked>
<map-feature id="mem35059" zoom="17">
<map-properties>
<table>
<tr><th>code</th><td>1200020</td></tr>
<tr><th>accuracy</th><td>26</td></tr>
<tr><th>valdate</th><td>1995</td></tr>
<tr>
<th>image</th>
<td>
<a href="https://www.veterans.gc.ca/eng/remembrance/memorials/national-inventory-canadian-memorials/details/9304">
<img src="https://www.veterans.gc.ca/images/remembrance/memorials/national-inventory-canadian-memorials/mem/35059-173a.jpg" width="60" height="60">
</a>
</td>
</tr>
<tr><th>theme</th><td>FO</td></tr>
<tr><th>type</th><td>2</td></tr>
<tr><th>elevation</th><td>61</td></tr>
<tr><th>altiaccu</th><td>5</td></tr>
</table>
</map-properties>
<map-geometry>
<map-point>
<map-coordinates>-75.705278 45.397778</map-coordinates>
</map-point>
</map-geometry>
</map-feature>
</layer->
A map-feature in a fetched XHTML MapML document
<layer- label="My Feature Layer" src="https://example.org/mem/35059.mapml"></layer->
35059.mapml:
<mapml- lang="en" xmlns="https://www.w3.org/1999/xhtml">
<map-head>
<map-title>The Man With Two Hats</map-title>
<map-meta http-equiv="Content-Type" content="text/mapml"></map-meta>
<map-meta charset="utf-8"></map-meta>
<map-meta name="projection" content="OSMTILE"></map-meta>
<map-meta name="cs" content="gcrs"></map-meta>
<map-link rel="license" href="https://open.canada.ca/en/open-government-licence-canada" title="Open Government License"/>
</map-head>
<map-body>
<map-feature id="mem35059">
<map-properties>
<table>
<tr><th>code</th><td>1200020</td></tr>
<tr><th>accuracy</th><td>26</td></tr>
<tr><th>valdate</th><td>1995</td></tr>
<tr>
<th>image</th>
<td>
<a href="https://www.veterans.gc.ca/eng/remembrance/memorials/national-inventory-canadian-memorials/details/9304">
<img src="https://www.veterans.gc.ca/images/remembrance/memorials/national-inventory-canadian-memorials/mem/35059-173a.jpg" width="60" height="60" />
</a>
</td>
</tr>
<tr><th>theme</th><td>FO</td></tr>
<tr><th>type</th><td>2</td></tr>
<tr><th>elevation</th><td>61</td></tr>
<tr><th>altiaccu</th><td>5</td></tr>
</table>
</map-properties>
<map-geometry>
<map-point>
<map-coordinates>-75.705278 45.397778</map-coordinates>
</map-point>
</map-geometry>
</map-feature>
</map-body>
</mapml->
Specifications
| Specification |
|---|
| MapML feature element |
Requirements
Report problems with these requirements on GitHub
requirementenhancementimpracticalundecidedunder discussion
| Spec | Viewer | API | |
|---|---|---|---|
| Vector features and overlays (5.2) | |||
Show pinpoint locations or custom markers on the map (5.2.1) | full | full | |
Draw polygons or polylines as stylable, interactive vector graphics (separate from the image tiles) (5.2.2) | full | full | |
| User navigation (pan and zoom) (5.4) | |||
Hide or show (and maybe dynamically load) vector features and labels on zoom (5.4.7) | full | experimental | |
| Custom styling (5.5) | |||
Apply custom styling to map markers and vector features (5.5.1) | full | limited |