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<map-a>

The <map-a> element is a proposal to extend the Web to include links between maps and locations. This element allows you to wrap parts of coordinates or entire geometries, making a link out of the location/area that is wrapped. When a feature geometry or geometry part is wrapped in a <map-a> element, it creates a blue outline that is 1 pixel wide around the feature (by default), that lets the user know it's a "linked feature".

Attributes​

href​

  • The URL that the wrapped location points to. Note - If the type of the <map-a> is text/mapml you can provide fragments, more on fragments below.

target​

  • This is where the linked URL will be displayed. See table below for more details.
  • Defaults to _self, in the absence of a valid value.

type​

  • This is the mime type of the linked URL's format. Options are text/html & text/mapml.
  • Defaults to text/mapml, in the absence of a valid type value.

inplace​

  • The inplace attribute is a boolean attribute - <map-a inplace href="..."><map-a>
  • When present, the default view-changing behavior is overridden and the map view does not change.

Target Behavior for text/mapml​

Target ValueBehavior
_selfReplaces the current layer with the linked URL layer.
_blankAdds the linked URL layer to the map.
_parentReplace all the layers with the linked URL layer.
_topNavigate the webpage to the linked URL.

Target Behavior for text/html​

Target ValueBehavior
_selfNavigate the webpage to the linked URL.
_blankOpen the linked URL in a new tab.
_parentNavigate the webpage to the linked URL.
_topNavigate the webpage to the linked URL.

Location fragments​

If the type attribute's value is text/mapml, you have the ability add a location fragment to the URL. This will pan & zoom the map to the given location.

Fragments are in the following format #zoom, longitude, latitude.

URL's solely defined in terms of location fragments pan and zoom the map to the given location regardless of the target value. i.e. <map-a href="#1, 20, 30">...</map-a> will pan to latitude: 30, longitude: 20 and zoom to level 1.

Examples​

Styling Linked Features​

To style linked features simply target the map-a class in your CSS, once a link is clicked you can target the map-a-visited class. See the example below:

<map-layer>
  <map-style>
    .map-a {
      stroke: red;
    }
    .map-a-visited {
      stroke: green;
    }
  </map-style>
  <map-feature>
    <map-properties>
      <h1>Basic</h1>
    </map-properties>
    <map-geometry>
      <map-a href="../externalMapML.mapml#2,-98,37">
        <map-polygon>
          <map-coordinates>2771 3106 2946 3113 2954 3210 2815 3192 2771 3106</map-coordinates>
        </map-polygon>
      </map-a>
    </map-geometry>
  </map-feature>
</map-layer>

Wrapping a Feature Type + Location Fragment​

<map-feature>
  <map-properties>
    <h1>Basic</h1>
  </map-properties>
  <map-geometry>
    <map-a href="../externalMapML.mapml#2,-98,37">
      <map-polygon>
        <map-coordinates>2771 3106 2946 3113 2954 3210 2815 3192 2771 3106</map-coordinates>
      </map-polygon>
    </map-a>
  </map-geometry>
</map-feature>

This will replace the current layer with the layer within externalMapML.mapml, once it's added the map will then goto zoomlevel: 2, longitude: -98, latitude: 37.

Wrapping a point coordinate with target="_blank"​

<map-feature>
  <map-properties>
    <h1>_blank target</h1>
  </map-properties>
  <map-geometry>
    <map-polygon>
      <map-coordinates>2771 3106 2946 3113 <map-a href="file.mapml" target="_blank"> 2954 3210 </map-a> 2815 3192 2771 3106</map-coordinates>
    </map-polygon>
  </map-geometry>
</map-feature>

In this example, a point will be created at (2954, 3210) which, once clicked, adds a new layer to the map.

Nested <map-a> definition and behavior​

<map-feature>
  <map-properties>
    <h1>Advanced Example</h1>
  </map-properties>
  <map-geometry>
    <map-a href="parent.mapml" target="_blank">
      <map-multipolygon>
        <map-polygon>
          <map-coordinates>2771 3106 2946 3113 <map-a href="webpage.html" target="_blank" type="text/mapml"> 2954 3210 </map-a> 2815 3192 2771 3106</map-coordinates>
        </map-polygon>
        <map-a href="nested.mapml" target="_top">
          <map-polygon>
            <map-coordinates>11 11 12 11 12 12 11 12</map-coordinates>
          </map-polygon>
        </map-a>
      </map-multipolygon>
    </map-a>
  </map-geometry>
</map-feature>

In this advanced example there are multiple nested <map-a>. The simple behavior is, the closest <map-a> is the link behavior that the given location/area will adopt.

Specifications​

Specification
HTML a element

Requirements​

Report problems with these requirements on GitHub

requirement enhancement impractical undecided under discussion

SpecViewerAPI
Vector features and overlays (5.2)
Support hyperlinks from markers or vector features (5.2.3)
fullfull
Interpreting locations and map positions (5.3)
Select map view from latitude and longitude point (5.3.1)
fullfullfull