/* 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/XML.js
*/
/**
* Class: OpenLayers.Format.Context
* Base class for both Format.WMC and Format.OWSContext
*/
OpenLayers.Format.Context = OpenLayers.Class({
/**
* APIProperty: version
* {String} Specify a version string if one is known.
*/
version: null,
/**
* Property: layerOptions
* {Object} Default options for layers created by the parser. These
* options are overridden by the options which are read from the
* capabilities document.
*/
layerOptions: null,
/**
* Property: layerParams
* {Object} Default parameters for layers created by the parser. This
* can be used e.g. to override DEFAULT_PARAMS for
* OpenLayers.Layer.WMS.
*/
layerParams: null,
/**
* Property: parser
* {Object} Instance of the versioned parser. Cached for multiple read and
* write calls of the same version.
*/
parser: null,
/**
* Constructor: OpenLayers.Format.Context
* Create a new parser for Context documents.
*
* Parameters:
* options - {Object} An optional object whose properties will be set on
* this instance.
*/
initialize: function(options) {
OpenLayers.Util.extend(this, options);
this.options = options;
},
/**
* APIMethod: read
* Read Context data from a string, and return an object with map
* properties and a list of layers.
*
* Parameters:
* data - {String} or {DOMElement} data to read/parse.
* options - {Object} The options object must contain a map property. If
* the map property is a string, it must be the id of a dom element
* where the new map will be placed. If the map property is an
* <OpenLayers.Map>, the layers from the context document will be added
* to the map.
*
* Returns:
* {<OpenLayers.Map>} A map based on the context.
*/
read: function(data, options) {
if(typeof data == "string") {
data = OpenLayers.Format.XML.prototype.read.apply(this, [data]);
}
var root = data.documentElement;
var version = this.version;
if(!version) {
version = root.getAttribute("version");
}
var parser = this.getParser(version);
var context = parser.read(data, options);
var map;
if(options && options.map) {
this.context = context;
if(options.map instanceof OpenLayers.Map) {
map = this.mergeContextToMap(context, options.map);
} else {
var mapOptions = options.map;
if(OpenLayers.Util.isElement(mapOptions) ||
typeof mapOptions == "string") {
// we assume mapOptions references a div
// element
mapOptions = {div: mapOptions};
}
map = this.contextToMap(context, mapOptions);
}
} else {
// not documented as part of the API, provided as a non-API option
map = context;
}
return map;
},
/**
* Method: getLayerFromContext
* Create a WMS layer from a layerContext object.
*
* Parameters:
* layerContext - {Object} An object representing a WMS layer.
*
* Returns:
* {<OpenLayers.Layer.WMS>} A WMS layer.
*/
getLayerFromContext: function(layerContext) {
var i, len;
// fill initial options object from layerContext
var options = {
queryable: layerContext.queryable, //keep queryable for api compatibility
visibility: layerContext.visibility,
maxExtent: layerContext.maxExtent,
metadata: OpenLayers.Util.applyDefaults(layerContext.metadata,
{styles: layerContext.styles}),
numZoomLevels: layerContext.numZoomLevels,
units: layerContext.units,
isBaseLayer: layerContext.isBaseLayer,
opacity: layerContext.opacity,
displayInLayerSwitcher: layerContext.displayInLayerSwitcher,
singleTile: layerContext.singleTile,
tileSize: (layerContext.tileSize) ?
new OpenLayers.Size(
layerContext.tileSize.width,
layerContext.tileSize.height
) : undefined,
minScale: layerContext.minScale || layerContext.maxScaleDenominator,
maxScale: layerContext.maxScale || layerContext.minScaleDenominator
};
if (this.layerOptions) {
OpenLayers.Util.applyDefaults(options, this.layerOptions);
}
var params = {
layers: layerContext.name,
transparent: layerContext.transparent,
version: layerContext.version
};
if (layerContext.formats && layerContext.formats.length>0) {
// set default value for params if current attribute is not positionned
params.format = layerContext.formats[0].value;
for (i=0, len=layerContext.formats.length; i<len; i++) {
var format = layerContext.formats[i];
if (format.current == true) {
params.format = format.value;
break;
}
}
}
if (layerContext.styles && layerContext.styles.length>0) {
for (i=0, len=layerContext.styles.length; i<len; i++) {
var style = layerContext.styles[i];
if (style.current == true) {
// three style types to consider
// 1) linked SLD
// 2) inline SLD
// 3) named style
if(style.href) {
params.sld = style.href;
} else if(style.body) {
params.sld_body = style.body;
} else {
params.styles = style.name;
}
break;
}
}
}
if (this.layerParams) {
OpenLayers.Util.applyDefaults(params, this.layerParams);
}
var layer = null;
var service = layerContext.service;
if (service == OpenLayers.Format.Context.serviceTypes.WFS) {
options.strategies = [new OpenLayers.Strategy.BBOX()];
options.protocol = new OpenLayers.Protocol.WFS({
url: layerContext.url,
// since we do not know featureNS, let the protocol
// determine it automagically using featurePrefix
featurePrefix: layerContext.name.split(":")[0],
featureType: layerContext.name.split(":").pop()
});
layer = new OpenLayers.Layer.Vector(
layerContext.title || layerContext.name,
options
);
} else if (service == OpenLayers.Format.Context.serviceTypes.KML) {
// use a vector layer with an HTTP Protcol and a Fixed strategy
options.strategies = [new OpenLayers.Strategy.Fixed()];
options.protocol = new OpenLayers.Protocol.HTTP({
url: layerContext.url,
format: new OpenLayers.Format.KML()
});
layer = new OpenLayers.Layer.Vector(
layerContext.title || layerContext.name,
options
);
} else if (service == OpenLayers.Format.Context.serviceTypes.GML) {
// use a vector layer with a HTTP Protocol and a Fixed strategy
options.strategies = [new OpenLayers.Strategy.Fixed()];
options.protocol = new OpenLayers.Protocol.HTTP({
url: layerContext.url,
format: new OpenLayers.Format.GML()
});
layer = new OpenLayers.Layer.Vector(
layerContext.title || layerContext.name,
options
);
} else if (layerContext.features) {
// inline GML or KML features
layer = new OpenLayers.Layer.Vector(
layerContext.title || layerContext.name,
options
);
layer.addFeatures(layerContext.features);
} else if (layerContext.categoryLayer !== true) {
layer = new OpenLayers.Layer.WMS(
layerContext.title || layerContext.name,
layerContext.url,
params,
options
);
}
return layer;
},
/**
* Method: getLayersFromContext
* Create an array of layers from an array of layerContext objects.
*
* Parameters:
* layersContext - {Array(Object)} An array of objects representing layers.
*
* Returns:
* {Array(<OpenLayers.Layer>)} An array of layers.
*/
getLayersFromContext: function(layersContext) {
var layers = [];
for (var i=0, len=layersContext.length; i<len; i++) {
var layer = this.getLayerFromContext(layersContext[i]);
if (layer !== null) {
layers.push(layer);
}
}
return layers;
},
/**
* Method: contextToMap
* Create a map given a context object.
*
* Parameters:
* context - {Object} The context object.
* options - {Object} Default map options.
*
* Returns:
* {<OpenLayers.Map>} A map based on the context object.
*/
contextToMap: function(context, options) {
options = OpenLayers.Util.applyDefaults({
maxExtent: context.maxExtent,
projection: context.projection
}, options);
var map = new OpenLayers.Map(options);
map.addLayers(this.getLayersFromContext(context.layersContext));
map.setCenter(
context.bounds.getCenterLonLat(),
map.getZoomForExtent(context.bounds, true)
);
return map;
},
/**
* Method: mergeContextToMap
* Add layers from a context object to a map.
*
* Parameters:
* context - {Object} The context object.
* map - {<OpenLayers.Map>} The map.
*
* Returns:
* {<OpenLayers.Map>} The same map with layers added.
*/
mergeContextToMap: function(context, map) {
map.addLayers(this.getLayersFromContext(context.layersContext));
return map;
},
/**
* APIMethod: write
* Write a context document given a map.
*
* Parameters:
* obj - {<OpenLayers.Map> | Object} A map or context object.
* options - {Object} Optional configuration object.
*
* Returns:
* {String} A context document string.
*/
write: function(obj, options) {
obj = this.toContext(obj);
var version = options && options.version;
var parser = this.getParser(version);
var context = parser.write(obj, options);
return context;
},
CLASS_NAME: "OpenLayers.Format.Context"
});
/**
* Constant: OpenLayers.Format.Context.serviceTypes
* Enumeration for service types
*/
OpenLayers.Format.Context.serviceTypes = {
"WMS": "urn:ogc:serviceType:WMS",
"WFS": "urn:ogc:serviceType:WFS",
"WCS": "urn:ogc:serviceType:WCS",
"GML": "urn:ogc:serviceType:GML",
"SLD": "urn:ogc:serviceType:SLD",
"FES": "urn:ogc:serviceType:FES",
"KML": "urn:ogc:serviceType:KML"
};