Adding Custom Layers

Introduction to Custom Layers

A map layer (†) is a set of geographic data (information) showing on your map.

  • The main layer on your map is the set of locations (marker icons) coming from your datasheet.

  • The custom layers will add context, relevance and insights into your own data, in a way of enriching your mapping experience

  • Layers would go from circles and heatmap, to overlay images, geographic data files and some others in between.

(†) This explanation is only for the purpose of this particular Mapping solution, but it might loosely apply to any GIS (geographic information system) application.

The image on the right might be showing only some of the layers already available or under development.

Circles layer

This layer would include a group of circles, each of them associated with a specific location (marker icon) on the map.

  • The radius of each circle depends on the datasheet value, under the header you choose from the list

  • The circle size would also depend on the unit you choose for that radius, from the available list (km,mi,m,ft - kilometer, mile, meter, foot)

  • The filling opacity (from 0 to 1) will determine the transparency of this layer, associated with its color intensity

  • The color of each circle will be the same color of its corresponding marker icon

  • The circles are bound to each location icon, so if the filter hides an icon, the circle would hide as well

p.s. Circles are rendered client-side, so too many might affect performance

Heatmap layer

As per Google Maps definition, a heatmap is a visualization used to depict the intensity of data at geographical points... when enabled, a colored overlay will appear on top of the map, with areas of higher intensity will be colored red, and areas of lower intensity will appear green.

The intensity could either depend on the number of locations in that area, or on the weight value associated with each location

  • The weight header (optional) will set the intensity per its values, as an alternative of the number of locations

  • The filling opacity (from 0 to 1) will determine the transparency of this layer, associated with its color intensity

  • The heatmap is a static layer that does not depend on the filtering status

GeoJSON layer

As described in Wikipedia: GeoJSON is an open standard format designed for representing simple geographical features, along with their non-spatial attributes.

A GeoJSON file can include several geometry feature types like: Point, LineString and Polygon, as well as groups and collections of them.

There are many GeoJSON resources available on the web that can be used

The map screenshot on the right is showing the neighbourhood boundaries in Toronto.

KML / KMZ / GeoRSS layer

As described by Google: KML (Keyhole Markup Language) is a file format used to display geographic data, it uses a tag-based structure with nested elements and attributes and is based on the XML standard.

While KMZ stands for a KML-Zipped (compressed) file, it also allows for folder structure and a richer markup content.

As described in Wikipedia: GeoRSS is a specification for encoding location as part of a Web feed like RSS (Really Simple Syndication).

The map screenshot on the right is showing the Subway (TTC) grid in Toronto

What's next?

... ground overlay images, static labels, topojson files, boundaries (administrative and others), isolines, ogc:wms ...

Let us know if we are missing some other layers of importance for you.

/dev: map full-screen-shots with 1920 x 1080 resolution @CB