MapIt: Code for SA
MapIt is a service that maps geographical points to administrative areas. It’s useful for anyone who has the co-ordinates of a particular point, and needs to find out what regions it lies within. It’s also great for looking up the shapes of all those boundaries.
You can download the source on Github.
MapIt API
The documentation below is for developers who want to use MapIt as a web service, describing its REST API. If that’s all Greek to you, please see our page for non-developers.
lookup by point
- URL:
- /point/[SRID]/[x],[y]
- /point/[SRID]/[x],[y]/box
- Parameters:
-
SRID is a unique number referring to a particular co-ordinate system; the one you probably are interested in is 4326 for WGS84 normal lon/lat.
x and y are the co-ordinates of the point in the co-ordinate system; note that x,y means longitude,latitude.
- Optional query parameters:
-
- type, to restrict results to a particular area type or types (multiple types separated by commas);
- generation, to return results for a previous generation.
- min_generation, to return results since that generation.
- Returns:
-
A hash of the areas that the point is contained within. If the /box version is used, only the area bounding boxes are considered.
lookup by area
- URL:
- /area/[area ID]
- /area/[area ID]/geometry
- /area/[area ID]/feature.geojson
- /area/[area ID].[kml or geojson or wkt]
- /area/[SRID]/[area ID].[kml or json or wkt]
- Area ID:
-
area ID is either an integer MapIt area id, or code-type:code. The code-type identifies the type of code. For example, the Municipal Demarcation Board (
MDB
) code for Gauteng isGT
and the corresponding area ID isMDB:GT
. - Optional query parameters:
- simplify_tolerance, a floating point parameter to simplify the polygons returned.
- Returns:
- Information on a particular area, including name, type, parent, and any associated codes (see below for details). The code lookups redirect to the area URI. geometry returns centroid, extent and area of the area.
lookup multiple areas
- URL:
- /areas/[area IDs]
- /areas/[area IDs].geojson
- /areas/[area IDs]/geometry
- /areas/[type(s)]
- /areas/[name prefix]
- Parameters:
- Separate multiple parameters with commas. Name prefix means it will return any area that starts with the string given.
- Optional query parameters:
- generation, to return areas in that generation (type and name lookups only).
- min_generation, to return areas since that generation (type and name lookups only).
- type, to restrict results to a type or types (multiple separated by commas; name lookup only).
- Returns:
-
Information on multiple areas that match the parameters provided, as a dictionary indexed by area ID. The geometry argument lets you fetch multiple single area geometry results at once.
Generations
- URL:
- /generations
- Returns:
- A list of all generations in this installation of MapIt.
- Example
- List of generations
General information
- Format
-
All calls return JSON, you can generally get an HTML representation by sticking .html on the end.
Whenever an area is returned from MapIt, it is as a dictionary with the following keys: id, name, country, type, parent_area, generation_low, generation_high, codes.
- Historical areas
- By default, calls will return active areas; for some calls you may specify a previous generation to look up instead.
About MapIt
MapIt was written back in 2003 as a postcode lookup to power the original mySociety sites such as WriteToThem. Over time it gained features such as point lookup (for FixMyStreet), and when Ordnance Survey data became freely available in 2010, it was rewritten and made public for the whole UK.
Versions have appeared in other countries, such as Norway, and in 2012 we released a global version based on OpenStreetMap data.
This is a modified version run by Code for South Africa. The source code is
available at github.com/Code4SA/mapit-za.
Usage & Licence
To maintain quality of service for our own websites, as well as our API users, this service is rate limited to an average of 1 call per second in a rolling 3 minute period.
If you use this service, we ask that you attribute MapIt at the point of use on sites or apps. Attribution should use the text “Powered by MapIt”, with a link back to this page.