HTMLLinkElement

This document is copied from the old "Custom Rendering API" page, and is under construction. It will eventually describe the API of the map-link custom element; the "Custom Rendering API" is currently sourced from the map-link custom element, which may change in the future.

The Custom Rendering API allows developers to circumvent MapML's rendering and draw anything within HTML's domain onto the map.

Custom Tiles

To render custom tiles using JavaScript, listen for the tileloadstart event on a templated layer's <map-link rel="tile"> element.

tileloadstart Event

This event is fired when a tile is first being created, the event contains the following structure in its detail property:

{
  x: 1,    // tilematrix x value of the tile loaded
  y: 2,    // tilematrix y value of the tile loaded
  zoom: 3, // zoom level of the tile loaded
  appendTile: function appendTile ( customTile ) {...} // pass custom tile as an argument to function
}

Example

The map:

<mapml-viewer projection="OSMTILE" zoom="0" lat="45" lon="-75" controls>
  <layer- label="Custom Tiles" checked>
    <map-meta name="zoom" content="min=0,max=23" ></map-meta>
    <map-extent units="OSMTILE" checked hidden>
      <map-input name="zoomLevel" type="zoom" min="0" max="23" value="1" ></map-input>
      <map-input name="row" type="location" axis="row" units="tilematrix" min="0" max="2" ></map-input>
      <map-input name="col" type="location" axis="column" units="tilematrix" min="0" max="2" ></map-input>
      <!-- listen for the tileloadstart event on this element -->
      <map-link rel="tile" title="" tref="" ></map-link>
    </map-extent>
  </layer->
</mapml-viewer>

The JavaScript for creating custom tiles:

let layer = document.querySelector("body > mapml-viewer > layer- > map-extent > map-link");
    layer.addEventListener("tileloadstart", (e) => {
      let customTile = document.createElement("p");
      customTile.innerHTML = `x: ${e.detail.x} y: ${e.detail.y} zoom: ${e.detail.zoom}`;
      e.detail.appendTile(customTile);
    });

In this example the customTile is an HTML <p>, but you can use any HTML Element. Simply append the created element using the (tileloadstart event).detail.appendTile() function, passing the custom tile as an argument of the function.

Custom Image

info

Needs to be implemented.

Specifications

Specification
HTMLLinkElement - not (fully) specified yet

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Requirements

Report problems with these requirements on GitHub

requirementenhancementimpracticalundecidedunder discussion

	Spec	Viewer	API
Properties	n/a	n/a	n/a
Methods	n/a	n/a	n/a
Events	none	n/a	partial *

Exceptions *

1. The <map-link> element will emit the tileloadstart event, but it's behaviour is experimental and requires markup to conform to the example given above

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