51 lines
1.2 KiB
JavaScript
51 lines
1.2 KiB
JavaScript
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var _ = require('underscore')
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var geojson = require('./geojson');
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var TopoJSON = require('topojson');
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function topojson() {
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}
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topojson.prototype = {};
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_.extend(topojson.prototype, geojson, {
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id: "topojson",
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getQuery: function(sql, options) {
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var sql = geojson.getQuery(sql, options);
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return sql + ' where ' + options.gn + ' is not null';
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},
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transform: function(result, options, callback) {
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toTopoJSON(result, options.gn, options.skipfields, callback);
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}
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})
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function toTopoJSON(data, gn, skipfields, callback){
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geojson.toGeoJSON(data, gn, function(err, geojson) {
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if ( err ) {
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callback(err, null);
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return;
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}
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var topology = TopoJSON.topology(geojson.features, {
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/* TODO: expose option to API for requesting an identifier
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"id": function(o) {
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console.log("id called with obj: "); console.dir(o);
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return o;
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},
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*/
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"quantization": 1e4, // TODO: expose option to API (use existing "dp" for this ?)
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"force-clockwise": true,
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"property-filter": function(d) {
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// TODO: delegate skipfields handling to toGeoJSON
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return skipfields.indexOf(d) != -1 ? null : d;
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}
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});
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callback(err, topology);
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});
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}
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module.exports = new topojson();
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