--- a/labs/openlayers/lib/OpenLayers/Format/GeoJSON.js +++ b/labs/openlayers/lib/OpenLayers/Format/GeoJSON.js @@ -1,1 +1,717 @@ - +/* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for + * full list of contributors). Published under the Clear BSD license. + * See http://svn.openlayers.org/trunk/openlayers/license.txt for the + * full text of the license. */ + +/** + * @requires OpenLayers/Format/JSON.js + * @requires OpenLayers/Feature/Vector.js + * @requires OpenLayers/Geometry/Point.js + * @requires OpenLayers/Geometry/MultiPoint.js + * @requires OpenLayers/Geometry/LineString.js + * @requires OpenLayers/Geometry/MultiLineString.js + * @requires OpenLayers/Geometry/Polygon.js + * @requires OpenLayers/Geometry/MultiPolygon.js + * @requires OpenLayers/Console.js + */ + +/** + * Class: OpenLayers.Format.GeoJSON + * Read and write GeoJSON. Create a new parser with the + * <OpenLayers.Format.GeoJSON> constructor. + * + * Inherits from: + * - <OpenLayers.Format.JSON> + */ +OpenLayers.Format.GeoJSON = OpenLayers.Class(OpenLayers.Format.JSON, { + + /** + * APIProperty: ignoreExtraDims + * {Boolean} Ignore dimensions higher than 2 when reading geometry + * coordinates. + */ + ignoreExtraDims: false, + + /** + * Constructor: OpenLayers.Format.GeoJSON + * Create a new parser for GeoJSON. + * + * Parameters: + * options - {Object} An optional object whose properties will be set on + * this instance. + */ + initialize: function(options) { + OpenLayers.Format.JSON.prototype.initialize.apply(this, [options]); + }, + + /** + * APIMethod: read + * Deserialize a GeoJSON string. + * + * Parameters: + * json - {String} A GeoJSON string + * type - {String} Optional string that determines the structure of + * the output. Supported values are "Geometry", "Feature", and + * "FeatureCollection". If absent or null, a default of + * "FeatureCollection" is assumed. + * filter - {Function} A function which will be called for every key and + * value at every level of the final result. Each value will be + * replaced by the result of the filter function. This can be used to + * reform generic objects into instances of classes, or to transform + * date strings into Date objects. + * + * Returns: + * {Object} The return depends on the value of the type argument. If type + * is "FeatureCollection" (the default), the return will be an array + * of <OpenLayers.Feature.Vector>. If type is "Geometry", the input json + * must represent a single geometry, and the return will be an + * <OpenLayers.Geometry>. If type is "Feature", the input json must + * represent a single feature, and the return will be an + * <OpenLayers.Feature.Vector>. + */ + read: function(json, type, filter) { + type = (type) ? type : "FeatureCollection"; + var results = null; + var obj = null; + if (typeof json == "string") { + obj = OpenLayers.Format.JSON.prototype.read.apply(this, + [json, filter]); + } else { + obj = json; + } + if(!obj) { + OpenLayers.Console.error("Bad JSON: " + json); + } else if(typeof(obj.type) != "string") { + OpenLayers.Console.error("Bad GeoJSON - no type: " + json); + } else if(this.isValidType(obj, type)) { + switch(type) { + case "Geometry": + try { + results = this.parseGeometry(obj); + } catch(err) { + OpenLayers.Console.error(err); + } + break; + case "Feature": + try { + results = this.parseFeature(obj); + results.type = "Feature"; + } catch(err) { + OpenLayers.Console.error(err); + } + break; + case "FeatureCollection": + // for type FeatureCollection, we allow input to be any type + results = []; + switch(obj.type) { + case "Feature": + try { + results.push(this.parseFeature(obj)); + } catch(err) { + results = null; + OpenLayers.Console.error(err); + } + break; + case "FeatureCollection": + for(var i=0, len=obj.features.length; i<len; ++i) { + try { + results.push(this.parseFeature(obj.features[i])); + } catch(err) { + results = null; + OpenLayers.Console.error(err); + } + } + break; + default: + try { + var geom = this.parseGeometry(obj); + results.push(new OpenLayers.Feature.Vector(geom)); + } catch(err) { + results = null; + OpenLayers.Console.error(err); + } + } + break; + } + } + return results; + }, + + /** + * Method: isValidType + * Check if a GeoJSON object is a valid representative of the given type. + * + * Returns: + * {Boolean} The object is valid GeoJSON object of the given type. + */ + isValidType: function(obj, type) { + var valid = false; + switch(type) { + case "Geometry": + if(OpenLayers.Util.indexOf( + ["Point", "MultiPoint", "LineString", "MultiLineString", + "Polygon", "MultiPolygon", "Box", "GeometryCollection"], + obj.type) == -1) { + // unsupported geometry type + OpenLayers.Console.error("Unsupported geometry type: " + + obj.type); + } else { + valid = true; + } + break; + case "FeatureCollection": + // allow for any type to be converted to a feature collection + valid = true; + break; + default: + // for Feature types must match + if(obj.type == type) { + valid = true; + } else { + OpenLayers.Console.error("Cannot convert types from " + + obj.type + " to " + type); + } + } + return valid; + }, + + /** + * Method: parseFeature + * Convert a feature object from GeoJSON into an + * <OpenLayers.Feature.Vector>. + * + * Parameters: + * obj - {Object} An object created from a GeoJSON object + * + * Returns: + * {<OpenLayers.Feature.Vector>} A feature. + */ + parseFeature: function(obj) { + var feature, geometry, attributes, bbox; + attributes = (obj.properties) ? obj.properties : {}; + bbox = (obj.geometry && obj.geometry.bbox) || obj.bbox; + try { + geometry = this.parseGeometry(obj.geometry); + } catch(err) { + // deal with bad geometries + throw err; + } + feature = new OpenLayers.Feature.Vector(geometry, attributes); + if(bbox) { + feature.bounds = OpenLayers.Bounds.fromArray(bbox); + } + if(obj.id) { + feature.fid = obj.id; + } + return feature; + }, + + /** + * Method: parseGeometry + * Convert a geometry object from GeoJSON into an <OpenLayers.Geometry>. + * + * Parameters: + * obj - {Object} An object created from a GeoJSON object + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + parseGeometry: function(obj) { + if (obj == null) { + return null; + } + var geometry, collection = false; + if(obj.type == "GeometryCollection") { + if(!(obj.geometries instanceof Array)) { + throw "GeometryCollection must have geometries array: " + obj; + } + var numGeom = obj.geometries.length; + var components = new Array(numGeom); + for(var i=0; i<numGeom; ++i) { + components[i] = this.parseGeometry.apply( + this, [obj.geometries[i]] + ); + } + geometry = new OpenLayers.Geometry.Collection(components); + collection = true; + } else { + if(!(obj.coordinates instanceof Array)) { + throw "Geometry must have coordinates array: " + obj; + } + if(!this.parseCoords[obj.type.toLowerCase()]) { + throw "Unsupported geometry type: " + obj.type; + } + try { + geometry = this.parseCoords[obj.type.toLowerCase()].apply( + this, [obj.coordinates] + ); + } catch(err) { + // deal with bad coordinates + throw err; + } + } + // We don't reproject collections because the children are reprojected + // for us when they are created. + if (this.internalProjection && this.externalProjection && !collection) { + geometry.transform(this.externalProjection, + this.internalProjection); + } + return geometry; + }, + + /** + * Property: parseCoords + * Object with properties corresponding to the GeoJSON geometry types. + * Property values are functions that do the actual parsing. + */ + parseCoords: { + /** + * Method: parseCoords.point + * Convert a coordinate array from GeoJSON into an + * <OpenLayers.Geometry>. + * + * Parameters: + * array - {Object} The coordinates array from the GeoJSON fragment. + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + "point": function(array) { + if (this.ignoreExtraDims == false && + array.length != 2) { + throw "Only 2D points are supported: " + array; + } + return new OpenLayers.Geometry.Point(array[0], array[1]); + }, + + /** + * Method: parseCoords.multipoint + * Convert a coordinate array from GeoJSON into an + * <OpenLayers.Geometry>. + * + * Parameters: + * array {Object} The coordinates array from the GeoJSON fragment. + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + "multipoint": function(array) { + var points = []; + var p = null; + for(var i=0, len=array.length; i<len; ++i) { + try { + p = this.parseCoords["point"].apply(this, [array[i]]); + } catch(err) { + throw err; + } + points.push(p); + } + return new OpenLayers.Geometry.MultiPoint(points); + }, + + /** + * Method: parseCoords.linestring + * Convert a coordinate array from GeoJSON into an + * <OpenLayers.Geometry>. + * + * Parameters: + * array - {Object} The coordinates array from the GeoJSON fragment. + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + "linestring": function(array) { + var points = []; + var p = null; + for(var i=0, len=array.length; i<len; ++i) { + try { + p = this.parseCoords["point"].apply(this, [array[i]]); + } catch(err) { + throw err; + } + points.push(p); + } + return new OpenLayers.Geometry.LineString(points); + }, + + /** + * Method: parseCoords.multilinestring + * Convert a coordinate array from GeoJSON into an + * <OpenLayers.Geometry>. + * + * Parameters: + * array - {Object} The coordinates array from the GeoJSON fragment. + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + "multilinestring": function(array) { + var lines = []; + var l = null; + for(var i=0, len=array.length; i<len; ++i) { + try { + l = this.parseCoords["linestring"].apply(this, [array[i]]); + } catch(err) { + throw err; + } + lines.push(l); + } + return new OpenLayers.Geometry.MultiLineString(lines); + }, + + /** + * Method: parseCoords.polygon + * Convert a coordinate array from GeoJSON into an + * <OpenLayers.Geometry>. + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + "polygon": function(array) { + var rings = []; + var r, l; + for(var i=0, len=array.length; i<len; ++i) { + try { + l = this.parseCoords["linestring"].apply(this, [array[i]]); + } catch(err) { + throw err; + } + r = new OpenLayers.Geometry.LinearRing(l.components); + rings.push(r); + } + return new OpenLayers.Geometry.Polygon(rings); + }, + + /** + * Method: parseCoords.multipolygon + * Convert a coordinate array from GeoJSON into an + * <OpenLayers.Geometry>. + * + * Parameters: + * array - {Object} The coordinates array from the GeoJSON fragment. + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + "multipolygon": function(array) { + var polys = []; + var p = null; + for(var i=0, len=array.length; i<len; ++i) { + try { + p = this.parseCoords["polygon"].apply(this, [array[i]]); + } catch(err) { + throw err; + } + polys.push(p); + } + return new OpenLayers.Geometry.MultiPolygon(polys); + }, + + /** + * Method: parseCoords.box + * Convert a coordinate array from GeoJSON into an + * <OpenLayers.Geometry>. + * + * Parameters: + * array - {Object} The coordinates array from the GeoJSON fragment. + * + * Returns: + * {<OpenLayers.Geometry>} A geometry. + */ + "box": function(array) { + if(array.length != 2) { + throw "GeoJSON box coordinates must have 2 elements"; + } + return new OpenLayers.Geometry.Polygon([ + new OpenLayers.Geometry.LinearRing([ + new OpenLayers.Geometry.Point(array[0][0], array[0][1]), + new OpenLayers.Geometry.Point(array[1][0], array[0][1]), + new OpenLayers.Geometry.Point(array[1][0], array[1][1]), + new OpenLayers.Geometry.Point(array[0][0], array[1][1]), + new OpenLayers.Geometry.Point(array[0][0], array[0][1]) + ]) + ]); + } + + }, + + /** + * APIMethod: write + * Serialize a feature, geometry, array of features into a GeoJSON string. + * + * Parameters: + * obj - {Object} An <OpenLayers.Feature.Vector>, <OpenLayers.Geometry>, + * or an array of features. + * pretty - {Boolean} Structure the output with newlines and indentation. + * Default is false. + * + * Returns: + * {String} The GeoJSON string representation of the input geometry, + * features, or array of features. + */ + write: function(obj, pretty) { + var geojson = { + "type": null + }; + if(obj instanceof Array) { + geojson.type = "FeatureCollection"; + var numFeatures = obj.length; + geojson.features = new Array(numFeatures); + for(var i=0; i<numFeatures; ++i) { + var element = obj[i]; + if(!element instanceof OpenLayers.Feature.Vector) { + var msg = "FeatureCollection only supports collections " + + "of features: " + element; + throw msg; + } + geojson.features[i] = this.extract.feature.apply( + this, [element] + ); + } + } else if (obj.CLASS_NAME.indexOf("OpenLayers.Geometry") == 0) { + geojson = this.extract.geometry.apply(this, [obj]); + } else if (obj instanceof OpenLayers.Feature.Vector) { + geojson = this.extract.feature.apply(this, [obj]); + if(obj.layer && obj.layer.projection) { + geojson.crs = this.createCRSObject(obj); + } + } + return OpenLayers.Format.JSON.prototype.write.apply(this, + [geojson, pretty]); + }, + + /** + * Method: createCRSObject + * Create the CRS object for an object. + * + * Parameters: + * object - {<OpenLayers.Feature.Vector>} + * + * Returns: + * {Object} An object which can be assigned to the crs property + * of a GeoJSON object. + */ + createCRSObject: function(object) { + var proj = object.layer.projection.toString(); + var crs = {}; + if (proj.match(/epsg:/i)) { + var code = parseInt(proj.substring(proj.indexOf(":") + 1)); + if (code == 4326) { + crs = { + "type": "OGC", + "properties": { + "urn": "urn:ogc:def:crs:OGC:1.3:CRS84" + } + }; + } else { + crs = { + "type": "EPSG", + "properties": { + "code": code + } + }; + } + } + return crs; + }, + + /** + * Property: extract + * Object with properties corresponding to the GeoJSON types. + * Property values are functions that do the actual value extraction. + */ + extract: { + /** + * Method: extract.feature + * Return a partial GeoJSON object representing a single feature. + * + * Parameters: + * feature - {<OpenLayers.Feature.Vector>} + * + * Returns: + * {Object} An object representing the point. + */ + 'feature': function(feature) { + var geom = this.extract.geometry.apply(this, [feature.geometry]); + return { + "type": "Feature", + "id": feature.fid == null ? feature.id : feature.fid, + "properties": feature.attributes, + "geometry": geom + }; + }, + + /** + * Method: extract.geometry + * Return a GeoJSON object representing a single geometry. + * + * Parameters: + * geometry - {<OpenLayers.Geometry>} + * + * Returns: + * {Object} An object representing the geometry. + */ + 'geometry': function(geometry) { + if (geometry == null) { + return null; + } + if (this.internalProjection && this.externalProjection) { + geometry = geometry.clone(); + geometry.transform(this.internalProjection, + this.externalProjection); + } + var geometryType = geometry.CLASS_NAME.split('.')[2]; + var data = this.extract[geometryType.toLowerCase()].apply(this, [geometry]); + var json; + if(geometryType == "Collection") { + json = { + "type": "GeometryCollection", + "geometries": data + }; + } else { + json = { + "type": geometryType, + "coordinates": data + }; + } + + return json; + }, + + /** + * Method: extract.point + * Return an array of coordinates from a point. + * + * Parameters: + * point - {<OpenLayers.Geometry.Point>} + * + * Returns: + * {Array} An array of coordinates representing the point. + */ + 'point': function(point) { + return [point.x, point.y]; + }, + + /** + * Method: extract.multipoint + * Return an array of point coordinates from a multipoint. + * + * Parameters: + * multipoint - {<OpenLayers.Geometry.MultiPoint>} + * + * Returns: + * {Array} An array of point coordinate arrays representing + * the multipoint. + */ + 'multipoint': function(multipoint) { + var array = []; + for(var i=0, len=multipoint.components.length; i<len; ++i) { + array.push(this.extract.point.apply(this, [multipoint.components[i]])); + } + return array; + }, + + /** + * Method: extract.linestring + * Return an array of coordinate arrays from a linestring. + * + * Parameters: + * linestring - {<OpenLayers.Geometry.LineString>} + * + * Returns: + * {Array} An array of coordinate arrays representing + * the linestring. + */ + 'linestring': function(linestring) { + var array = []; + for(var i=0, len=linestring.components.length; i<len; ++i) { + array.push(this.extract.point.apply(this, [linestring.components[i]])); + } + return array; + }, + + /** + * Method: extract.multilinestring + * Return an array of linestring arrays from a linestring. + * + * Parameters: + * linestring - {<OpenLayers.Geometry.MultiLineString>} + * + * Returns: + * {Array} An array of linestring arrays representing + * the multilinestring. + */ + 'multilinestring': function(multilinestring) { + var array = []; + for(var i=0, len=multilinestring.components.length; i<len; ++i) { + array.push(this.extract.linestring.apply(this, [multilinestring.components[i]])); + } + return array; + }, + + /** + * Method: extract.polygon + * Return an array of linear ring arrays from a polygon. + * + * Parameters: + * polygon - {<OpenLayers.Geometry.Polygon>} + * + * Returns: + * {Array} An array of linear ring arrays representing the polygon. + */ + 'polygon': function(polygon) { + var array = []; + for(var i=0, len=polygon.components.length; i<len; ++i) { + array.push(this.extract.linestring.apply(this, [polygon.components[i]])); + } + return array; + }, + + /** + * Method: extract.multipolygon + * Return an array of polygon arrays from a multipolygon. + * + * Parameters: + * multipolygon - {<OpenLayers.Geometry.MultiPolygon>} + * + * Returns: + * {Array} An array of polygon arrays representing + * the multipolygon + */ + 'multipolygon': function(multipolygon) { + var array = []; + for(var i=0, len=multipolygon.components.length; i<len; ++i) { + array.push(this.extract.polygon.apply(this, [multipolygon.components[i]])); + } + return array; + }, + + /** + * Method: extract.collection + * Return an array of geometries from a geometry collection. + * + * Parameters: + * collection - {<OpenLayers.Geometry.Collection>} + * + * Returns: + * {Array} An array of geometry objects representing the geometry + * collection. + */ + 'collection': function(collection) { + var len = collection.components.length; + var array = new Array(len); + for(var i=0; i<len; ++i) { + array[i] = this.extract.geometry.apply( + this, [collection.components[i]] + ); + } + return array; + } + + + }, + + CLASS_NAME: "OpenLayers.Format.GeoJSON" + +}); +