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GeoDataService

GeoDataService is an Angular Factory in the SVG module with the name geodata.js. It provides an API to fetch and cache TopoJSON data from the server, as well as providing a way of creating a path generator for the data to be used to render the map in an SVG layer. To use this API, see the documentation on injecting Angular services.

NameSummary
clearCacheClear the cache for TopoJSON data.
fetchTopoDataGet TopoData via a $http request.
createPathGeneratorConverts given TopoJSON format data into corresponding GeoJSON data and creates a path generator for it.
rescaleProjectionAdjust projection scale and translation to fill the view with the map.

Function Descriptions

clearCache

Clear the cache for TopoJSON data.

Example UsageArgumentsReturn Value
gds.clearCache();nonenone, but clears the cache

fetchTopoData

Get TopoData via a $http request.

Example UsageArgumentsReturn Value
var promise = gds.fetchTopoData(id);

id - string of the name of the TopoJSON map, or the URL of where the TopoJSON is

  • IDs that start with an asterisk (*) identify maps bundled with the ONOS GUI.
  • IDs that do not start with an asterisk are assumed to be URLs to externally provided data.

an $http promise object with the following extra members:

meta: an object with members id (given), url (used to get the data), and wasCached (boolean)

topodata: TopoJSON data upon response from server

createPathGenerator

Converts given TopoJSON format data into corresponding GeoJSON data and creates a path generator for it.

Example UsageArgumentsReturn Value
var pathGen = gds.createPathGnerator(topoData, opts);

topoData - the topodata from the returned fetchTopoData promise object

opts - object that allows the override of default settings (see below)

an object with the following members:

geodata: d3 feature data

pathgen: d3 geo path projection

settings: the settings object used to create the map

Default Settings

These can be overwritten in opts.

var defaultGenSettings = {
    objectTag: 'states',                  // the top level member under "objects" tag in TopoJSON
    projection: d3.geo.mercator(),        // type of geo projection, see https://github.com/mbostock/d3/wiki/Geo-Projections
    logicalSize: 1000,                    // logical size of the projection
    mapFillScale: .95                     // how large the map fills the area
};

rescaleProjection

Adjust projection scale and translation to fill the view with the map.

Example UsageArgumentsReturn Value
gds.rescaleProjection(proj, mfs, dim, path, geoData);

see defaultGenSettings from above

proj - the projection for the map

mfs - map fill scale

dim - logical size

path - the path projection

geoData - the TopoJSON feature data

none, but scales and translates the map to fit in the space
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