Files
openlayers/src/ol/source/wmtssource.js
2013-04-09 19:19:45 +02:00

258 lines
8.2 KiB
JavaScript

goog.provide('ol.source.WMTS');
goog.provide('ol.source.WMTSRequestEncoding');
goog.require('goog.array');
goog.require('goog.asserts');
goog.require('goog.math');
goog.require('goog.object');
goog.require('goog.uri.utils');
goog.require('ol.Extent');
goog.require('ol.TileCoord');
goog.require('ol.TileUrlFunction');
goog.require('ol.TileUrlFunctionType');
goog.require('ol.projection');
goog.require('ol.source.ImageTileSource');
goog.require('ol.tilegrid.WMTS');
/**
* @enum {string}
*/
ol.source.WMTSRequestEncoding = {
KVP: 'KVP', // see spec §8
REST: 'REST' // see spec §10
};
/**
* @constructor
* @extends {ol.source.ImageTileSource}
* @param {ol.source.WMTSOptions} options WMTS options.
*/
ol.source.WMTS = function(options) {
// TODO: add support for TileMatrixLimits
var version = goog.isDef(options.version) ? options.version : '1.0.0';
var format = goog.isDef(options.format) ? options.format : 'image/jpeg';
var dimensions = options.dimensions || {};
// FIXME: should we guess this requestEncoding from options.url(s)
// structure? that would mean KVP only if a template is not provided.
var requestEncoding = goog.isDef(options.requestEncoding) ?
options.requestEncoding : ol.source.WMTSRequestEncoding.KVP;
// FIXME: should we create a default tileGrid?
// we could issue a getCapabilities xhr to retrieve missing configuration
var tileGrid = options.tileGrid;
var context = {
'Layer': options.layer,
'style': options.style,
'Style': options.style,
'TileMatrixSet': options.matrixSet
};
goog.object.extend(context, dimensions);
var kvpParams;
if (requestEncoding == ol.source.WMTSRequestEncoding.KVP) {
kvpParams = {
'Service': 'WMTS',
'Request': 'GetTile',
'Version': version,
'Format': format,
'TileMatrix': '{TileMatrix}',
'TileRow': '{TileRow}',
'TileCol': '{TileCol}'
};
goog.object.extend(kvpParams, context);
}
/**
* @param {string} template Template.
* @return {ol.TileUrlFunctionType} Tile URL function.
*/
function createFromWMTSTemplate(template) {
return function(tileCoord) {
if (goog.isNull(tileCoord)) {
return undefined;
} else {
var localContext = {
'TileMatrix': tileGrid.getMatrixId(tileCoord.z),
'TileCol': tileCoord.x,
'TileRow': tileCoord.y
};
if (requestEncoding != ol.source.WMTSRequestEncoding.KVP) {
goog.object.extend(localContext, context);
}
var url = template;
for (var key in localContext) {
// FIXME: should we filter properties with hasOwnProperty?
url = url.replace('{' + key + '}', localContext[key])
.replace('%7B' + key + '%7D', localContext[key]);
}
return url;
}
};
}
var tileUrlFunction = ol.TileUrlFunction.nullTileUrlFunction;
var urls = options.urls;
if (!goog.isDef(urls) && goog.isDef(options.url)) {
urls = ol.TileUrlFunction.expandUrl(options.url);
}
if (goog.isDef(urls)) {
tileUrlFunction = ol.TileUrlFunction.createFromTileUrlFunctions(
goog.array.map(urls, function(url) {
if (goog.isDef(kvpParams)) {
// TODO: we may want to create our own appendParams function
// so that params order conforms to wmts spec guidance,
// and so that we can avoid to escape special template params
url = goog.uri.utils.appendParamsFromMap(url, kvpParams);
}
return createFromWMTSTemplate(url);
}));
}
var tmpExtent = new ol.Extent(0, 0, 0, 0);
var tmpTileCoord = new ol.TileCoord(0, 0, 0);
tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
function(tileCoord, projection) {
var tileGrid = this.getTileGrid();
goog.asserts.assert(!goog.isNull(tileGrid));
if (tileGrid.getResolutions().length <= tileCoord.z) {
return null;
}
var x = tileCoord.x;
var y = -tileCoord.y - 1;
var tileExtent = tileGrid.getTileCoordExtent(tileCoord);
var projectionExtent = projection.getExtent();
var extent = goog.isDef(options.extent) ?
options.extent : projectionExtent;
if (!goog.isNull(extent) && projection.isGlobal() &&
extent.minX === projectionExtent.minX &&
extent.maxX === projectionExtent.maxX) {
var numCols = Math.ceil(
(extent.maxX - extent.minX) /
(tileExtent.maxX - tileExtent.minX));
x = goog.math.modulo(x, numCols);
tmpTileCoord.z = tileCoord.z;
tmpTileCoord.x = x;
tmpTileCoord.y = tileCoord.y;
tileExtent = tileGrid.getTileCoordExtent(tmpTileCoord, tmpExtent);
}
if (!tileExtent.intersects(extent)) {
return null;
}
return new ol.TileCoord(tileCoord.z, x, y);
},
tileUrlFunction);
goog.base(this, {
attributions: options.attributions,
crossOrigin: options.crossOrigin,
extent: options.extent,
projection: options.projection,
tileGrid: tileGrid,
tileUrlFunction: tileUrlFunction
});
};
goog.inherits(ol.source.WMTS, ol.source.ImageTileSource);
/**
* @param {Object} wmtsCap An object representing the capabilities document.
* @param {string} layer The layer identifier.
* @return {ol.source.WMTSOptions} WMTS source options object.
*/
ol.source.WMTS.optionsFromCapabilities = function(wmtsCap, layer) {
// TODO: add support for TileMatrixLimits
var layers = wmtsCap['contents']['layers'];
var l = goog.array.find(layers, function(elt, index, array) {
return elt['identifier'] == layer;
});
goog.asserts.assert(!goog.isNull(l));
goog.asserts.assert(l['tileMatrixSetLinks'].length > 0);
var matrixSet = /** @type {string} */
(l['tileMatrixSetLinks'][0]['tileMatrixSet']);
var format = /** @type {string} */ (l['formats'][0]);
var idx = goog.array.findIndex(l['styles'], function(elt, index, array) {
return elt['isDefault'];
});
if (idx < 0) {
idx = 0;
}
var style = /** @type {string} */ (l['styles'][idx]['identifier']);
var dimensions = {};
goog.array.forEach(l['dimensions'], function(elt, index, array) {
var key = elt['identifier'];
var value = elt['default'];
if (goog.isDef(value)) {
goog.asserts.assert(goog.array.indexOf(elt['values'], value) >= 0);
} else {
value = elt['values'][0];
}
goog.asserts.assert(goog.isDef(value));
dimensions[key] = value;
});
var matrixSets = wmtsCap['contents']['tileMatrixSets'];
goog.asserts.assert(matrixSet in matrixSets);
var matrixSetObj = matrixSets[matrixSet];
var tileGrid = ol.tilegrid.WMTS.createFromCapabilitiesMatrixSet(
matrixSetObj);
var projection = ol.projection.get(matrixSetObj['supportedCRS']);
var gets = wmtsCap['operationsMetadata']['GetTile']['dcp']['http']['get'];
var encodings = goog.object.getKeys(
gets[0]['constraints']['GetEncoding']['allowedValues']);
goog.asserts.assert(encodings.length > 0);
var urls;
var requestEncoding;
switch (encodings[0]) {
case 'REST':
case 'RESTful':
// The OGC documentation is not clear if we should use REST or RESTful,
// ArcGis use RESTful, and OpenLayers use REST.
requestEncoding = ol.source.WMTSRequestEncoding.REST;
goog.asserts.assert(l['resourceUrls'].hasOwnProperty('tile'));
goog.asserts.assert(l['resourceUrls']['tile'].hasOwnProperty(format));
urls = /** @type {Array.<string>} */
(l['resourceUrls']['tile'][format]);
break;
case 'KVP':
requestEncoding = ol.source.WMTSRequestEncoding.REST;
urls = [];
goog.array.forEach(gets, function(elt, index, array) {
if (elt['constraints']['GetEncoding']['allowedValues'].hasOwnProperty(
ol.source.WMTSRequestEncoding.KVP)) {
urls.push(/** @type {string} */ (elt['url']));
}
});
goog.asserts.assert(urls.length > 0);
break;
default:
goog.asserts.fail();
}
return {
urls: urls,
layer: layer,
matrixSet: matrixSet,
format: format,
projection: projection,
requestEncoding: requestEncoding,
tileGrid: tileGrid,
style: style,
dimensions: dimensions
};
};