terriajs
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Geospatial data visualization platform.
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JavaScript
'use strict';
/*global require*/
var ArcGisMapServerImageryProvider = require('terriajs-cesium/Source/Scene/ArcGisMapServerImageryProvider');
var defaultValue = require('terriajs-cesium/Source/Core/defaultValue');
var defined = require('terriajs-cesium/Source/Core/defined');
var defineProperties = require('terriajs-cesium/Source/Core/defineProperties');
var Ellipsoid = require('terriajs-cesium/Source/Core/Ellipsoid');
var getToken = require('./getToken');
var ImageryLayerCatalogItem = require('./ImageryLayerCatalogItem');
var ImageryProvider = require('terriajs-cesium/Source/Scene/ImageryProvider');
var inherit = require('../Core/inherit');
var knockout = require('terriajs-cesium/Source/ThirdParty/knockout');
var Legend = require('../Map/Legend');
var LegendUrl = require('../Map/LegendUrl');
var loadJson = require('../Core/loadJson');
var Metadata = require('./Metadata');
var MetadataItem = require('./MetadataItem');
var overrideProperty = require('../Core/overrideProperty');
var proj4 = require('proj4').default;
var proj4definitions = require ('../Map/Proj4Definitions');
var proxyCatalogItemUrl = require('./proxyCatalogItemUrl');
var Rectangle = require('terriajs-cesium/Source/Core/Rectangle');
var replaceUnderscores = require('../Core/replaceUnderscores');
var RequestErrorEvent = require('terriajs-cesium/Source/Core/RequestErrorEvent');
var TerriaError = require('../Core/TerriaError');
var unionRectangleArray = require('../Map/unionRectangleArray');
var URI = require('urijs');
var WebMercatorTilingScheme = require('terriajs-cesium/Source/Core/WebMercatorTilingScheme');
var when = require('terriajs-cesium/Source/ThirdParty/when');
/**
* A {@link ImageryLayerCatalogItem} representing a layer from an Esri ArcGIS MapServer.
*
* @alias ArcGisMapServerCatalogItem
* @constructor
* @extends ImageryLayerCatalogItem
*
* @param {Terria} terria The Terria instance.
*/
var ArcGisMapServerCatalogItem = function(terria) {
ImageryLayerCatalogItem.call(this, terria);
this._legendUrl = undefined; // a LegendUrl object for a legend provided explicitly
this._generatedLegendUrl = undefined; // a LegendUrl object pointing to a data URL of a legend generated by us
this._mapServerData = undefined; // cached JSON response of server metadata
this._layersData = undefined; // cached JSON response of layers metadata
this._thisLayerInLayersData = undefined; // cached JSON response of one single layer
this._allLayersInLayersData = undefined; // cached JSON response of either all layers, or [one layer].
this._lastToken = undefined; // cached token
this._newTokenRequestInFlight = undefined; // a promise for an in-flight token request
/**
* Gets or sets the comma-separated list of layer IDs to show. If this property is undefined,
* all layers are shown.
* @type {String}
*/
this.layers = undefined;
/**
* Gets or sets the denominator of the largest scale (smallest denominator) for which tiles should be requested. For example, if this value is 1000, then tiles representing
* a scale larger than 1:1000 (i.e. numerically smaller denominator, when zooming in closer) will not be requested. Instead, tiles of the largest-available scale, as specified by this property,
* will be used and will simply get blurier as the user zooms in closer.
* @type {Number}
*/
this.maximumScale = undefined;
/**
* Gets or sets the denominator of the largest scale (smallest denominator) beyond which to show a message explaining that no further zoom levels are available, at the request
* of the data custodian.
* @type {Number}
*/
this.maximumScaleBeforeMessage = undefined;
/**
* Gets or sets a value indicating whether to continue showing tiles when the {@link ArcGisMapServerCatalogItem#maximumScaleBeforeMessage}
* is exceeded. This property is observable.
* @type {Boolean}
* @default true
*/
this.showTilesAfterMessage = true;
/**
* Gets or sets a value indicating whether features in this catalog item can be selected by clicking them on the map.
* @type {Boolean}
* @default true
*/
this.allowFeaturePicking = true;
/**
* Gets or sets the URL to use for requesting tokens.
* @type {String}
*/
this.tokenUrl = undefined;
/**
* Gets or sets the additional parameters to pass to the WMS server when requesting images.
* All parameter names must be entered in lowercase in order to be consistent with references in TerrisJS code.
* If this property is undefined, {@link WebMapServiceCatalogItem.defaultParameters} is used.
* @type {Object}
*/
this.parameters = {};
knockout.track(this, ['layers', 'maximumScale', '_legendUrl', '_generatedLegendUrl', 'maximumScaleBeforeMessage', 'showTilesAfterMessage', 'allowFeaturePicking', 'tokenUrl', 'parameters']);
// metadataUrl and legendUrl are derived from url if not explicitly specified.
overrideProperty(this, 'metadataUrl', {
get: function() {
if (defined(this._metadataUrl)) {
return this._metadataUrl;
}
return cleanUrl(this.url);
},
set: function(value) {
this._metadataUrl = value;
}
});
overrideProperty(this, 'legendUrl', {
get: function() {
if (defined(this._legendUrl)) {
return this._legendUrl;
} else if (defined(this._generatedLegendUrl)) {
return this._generatedLegendUrl;
} else {
return new LegendUrl(cleanUrl(this.url) + '/legend');
}
},
set: function(value) {
this._legendUrl = value;
}
});
// The dataUrl must be explicitly specified. Don't try to use `url` as the the dataUrl.
overrideProperty(this, 'dataUrl', {
get: function() {
return this._dataUrl;
},
set: function(value) {
this._dataUrl = value;
}
});
overrideProperty(this, 'dataUrlType', {
get: function() {
return this._dataUrlType;
},
set: function(value) {
this._dataUrlType = value;
}
});
};
inherit(ImageryLayerCatalogItem, ArcGisMapServerCatalogItem);
defineProperties(ArcGisMapServerCatalogItem.prototype, {
/**
* Gets the type of data item represented by this instance.
* @memberOf ArcGisMapServerCatalogItem.prototype
* @type {String}
*/
type: {
get: function() {
return 'esri-mapServer';
}
},
/**
* Gets a human-readable name for this type of data source, 'Esri ArcGIS MapServer'.
* @memberOf ArcGisMapServerCatalogItem.prototype
* @type {String}
*/
typeName: {
get: function() {
return 'Esri ArcGIS MapServer';
}
},
/**
* Gets the metadata associated with this data source and the server that provided it, if applicable.
* @memberOf ArcGisMapServerCatalogItem.prototype
* @type {Metadata}
*/
metadata: {
get: function() {
if (!defined(this._metadata)) {
this._metadata = requestMetadata(this);
}
return this._metadata;
}
}
});
/*
Goal: To match URLs ending in MapServer/0 where 0 is any number
but also allowing for an optional final /, and ? and # terms.
For simplicity, match any path that includes /MapServer/0
*/
var partsRegex = new RegExp('^(.*\/MapServer\/)([0-9]+)', 'i');
function getBaseURI(item) {
var uri = new URI(item.url);
if (uri.segment(-1).match(/\d+/)) {
uri.segment(-1, '');
}
return uri;
}
function getJson(item, uri) {
return loadJson(proxyCatalogItemUrl(item, uri.addQuery('f', 'json').toString(), '1d'));
}
ArcGisMapServerCatalogItem.prototype._load = function() {
var that = this;
if (!defined(this._mapServerData) || !defined(this._layersData)) {
var uri = new URI(this.url);
var layers = 'layers';
if (uri.segment(-1).match(/\d+/)) {
// URL is a single REST layer, like .../arcgis/rest/services/Society/Society_SCRC/MapServer/16
layers = uri.segment(-1);
this.layers = layers; // ## is this ok to do?
}
var promise = when();
if (this.tokenUrl) {
promise = getToken(this.terria, this.tokenUrl, this.url);
}
return promise.then(function (token) {
that._lastToken = token;
var serviceUri = getBaseURI(that);
var layersUri = getBaseURI(that).segment(layers); // either 'layers' or a number
var legendUri = getBaseURI(that).segment('legend');
if (token) {
serviceUri.addQuery('token', token);
layersUri.addQuery('token', token);
legendUri.addQuery('token', token);
}
var serviceMetadata = that._mapServerData || getJson(that, serviceUri);
var layersMetadata = that._layersData || getJson(that, layersUri);
var legendMetadata = that._legendData || getJson(that, legendUri);
return when.all([serviceMetadata, layersMetadata, legendMetadata]).then(function(results) {
if (defined(results[1].layers)) {
that.updateFromMetadata(results[0], results[1], results[2], false);
} else if (defined(results[1].id)) {
// Results of a single layer query. Make it look like a multi layer query result.
that.updateFromMetadata(results[0], {"layers": [results[1]]}, results[2], false, results[1]);
} else {
var message = defined(results[0].error) ? results[0].error.message : 'This dataset returned unusable metadata.';
throw new TerriaError({
title: 'ArcGIS Mapserver Error',
message: '<p>' + message + '</p><p>Please report it by \
sending an email to <a href="mailto:' + that.terria.supportEmail + '">' + that.terria.supportEmail + '</a>.</p>'
});
}
});
});
}
};
ArcGisMapServerCatalogItem.prototype.handleTileError = function(detailsRequestPromise, imageryProvider, x, y, level) {
if (!defined(this.tokenUrl)) {
return detailsRequestPromise;
}
const that = this;
return detailsRequestPromise.otherwise(function(e) {
if (e && (e.statusCode === 498 || e.statusCode === 499)) {
return requestToken(that, imageryProvider);
} else {
return when.reject(e);
}
}).then(function(responseText) {
// On an `export` request with an expired or invalid token, ArcGIS returns
// a 200 response with a JSON payload indicating an error.
try {
const json = JSON.parse(responseText);
if (json && json.error && json.error.code) {
if (json.error.code === 498 || json.error.code === 499) {
return requestToken(that, imageryProvider);
} else {
// A non-token error occurred, tile fails.
return when.reject(new RequestErrorEvent(json.error.code, json.error.message));
}
}
} catch (e) {
}
// Not JSON or not an error, so let's retry.
return responseText;
});
};
function requestToken(catalogItem, imageryProvider) {
if (!defined(catalogItem._newTokenRequestInFlight)) {
catalogItem._newTokenRequestInFlight = getToken(catalogItem.terria, catalogItem.tokenUrl, catalogItem.url).then(function(token) {
catalogItem._lastToken = token;
imageryProvider.token = token;
catalogItem._newTokenRequestInFlight = undefined;
});
}
return catalogItem._newTokenRequestInFlight;
}
ArcGisMapServerCatalogItem.prototype._createImageryProvider = function() {
var maximumLevel = maximumScaleToLevel(this.maximumScale);
var r = partsRegex.exec(this.url);
var baseUrl = (r && r[2]) ? r[1] : this.url;
// Strip trailing forward slash if exists
baseUrl = baseUrl.replace(/\/$/g, '');
const dynamicRequired = this.layers && this.layers.length > 0;
const imageryOptions = {
url: cleanAndProxyUrl(this, baseUrl),
layers: getLayerList(this),
tilingScheme: new WebMercatorTilingScheme(),
maximumLevel: maximumLevel,
mapServerData: this._mapServerData,
enablePickFeatures: defaultValue(this.allowFeaturePicking, true),
usePreCachedTilesIfAvailable: !dynamicRequired,
parameters: this.parameters
};
if (defined(this._lastToken)) {
// Using the last token is an optimization; if its still valid it will speed up
// the operation and if its not then it will just be requested when its needed.
imageryOptions.token = this._lastToken;
}
var imageryProvider = new ArcGisMapServerImageryProvider(imageryOptions);
var maximumLevelBeforeMessage = maximumScaleToLevel(this.maximumScaleBeforeMessage);
if (defined(maximumLevelBeforeMessage)) {
var realRequestImage = imageryProvider.requestImage;
var messageDisplayed = false;
var that = this;
imageryProvider.requestImage = function(x, y, level) {
if (level > maximumLevelBeforeMessage) {
if (!messageDisplayed) {
that.terria.error.raiseEvent(new TerriaError({
title: 'Dataset will not be shown at this scale',
message: 'The "' + that.name + '" dataset will not be shown when zoomed in this close to the map because the data custodian has ' +
'indicated that the data is not intended or suitable for display at this scale. Click the dataset\'s Info button on the ' +
'Now Viewing tab for more information about the dataset and the data custodian.'
}));
messageDisplayed = true;
}
if (!that.showTilesAfterMessage) {
return ImageryProvider.loadImage(imageryProvider, that.terria.baseUrl + 'images/blank.png');
}
}
return realRequestImage.call(imageryProvider, x, y, level);
};
}
return imageryProvider;
};
var noDataRegex = /^No[\s_-]?Data$/i;
/**
* Updates this catalog item from a the MapServer metadata and the MapServer/layers metadata.
* @param {Object} mapServerJson The JSON metadata found at the /MapServer URL.
* @param {Object} layersJson The JSON metadata found at the /MapServer/layers URL.
* @param {Boolean} [overwrite=false] True to overwrite existing property values with data from the metadata; false to
* preserve any existing values.
* @param {Object} [thisLayerJson] A reference to this layer within the `layersJson` object. If this parameter is not
* specified, the layer is found automatically based on this catalog item's `layers` property.
*/
ArcGisMapServerCatalogItem.prototype.updateFromMetadata = function(mapServerJson, layersJson, legendJson, overwrite, thisLayerJson) {
var i;
if (!defined(thisLayerJson)) {
thisLayerJson = findLayers(layersJson.layers, this.layers);
if (!defined(thisLayerJson)) {
return;
}
if (defined(this.layers)) {
var layers = this.layers.split(',');
for (i = 0; i < thisLayerJson.length; ++i) {
if (!defined(thisLayerJson[i])) {
console.log('A layer with the name or ID \"' + layers[i] + '\" does not exist on the ArcGIS MapServer - ignoring it.');
thisLayerJson.splice(i, 1);
layers.splice(i, 1);
--i;
}
}
}
if (thisLayerJson.length === 0) {
return;
}
}
this._mapServerData = mapServerJson;
this._layersData = layersJson;
this._legendData = legendJson;
if (Array.isArray(thisLayerJson)) {
this._thisLayerInLayersData = thisLayerJson[0];
this._allLayersInLayersData = thisLayerJson;
thisLayerJson = this._thisLayerInLayersData;
} else {
this._thisLayerInLayersData = thisLayerJson;
this._allLayersInLayersData = [thisLayerJson];
}
updateValue(this, overwrite, 'dataCustodian', getDataCustodian(mapServerJson));
updateValue(this, overwrite, 'rectangle', getRectangleFromLayers(this._allLayersInLayersData));
// if catalog contains a hand-crafted legend image, we respect it.
if (!defined(this._legendUrl)) {
this.loadLegendFromJson(legendJson); // a promise.
}
var minimumMaxScale = Number.MAX_VALUE;
var minimumMaxScaleWithoutNoData = Number.MAX_VALUE;
for (i = 0; i < this._allLayersInLayersData.length; ++i) {
var l = this._allLayersInLayersData[i];
if (l.maxScale < minimumMaxScale) {
minimumMaxScale = l.maxScale;
}
if (!noDataRegex.test(l.name) && l.maxScale < minimumMaxScaleWithoutNoData) {
minimumMaxScaleWithoutNoData = l.maxScale;
}
}
if (minimumMaxScale !== Number.MAX_VALUE) {
updateValue(this, overwrite, 'maximumScale', minimumMaxScale);
}
if (minimumMaxScaleWithoutNoData !== minimumMaxScale) {
updateValue(this, overwrite, 'maximumScaleBeforeMessage', minimumMaxScaleWithoutNoData);
}
updateInfoSection(this, overwrite, 'Data Description', thisLayerJson.description);
updateInfoSection(this, overwrite, 'Service Description', mapServerJson.serviceDescription);
updateInfoSection(this, overwrite, 'Service Description', mapServerJson.description);
var copyrightText = defined(thisLayerJson.copyrightText) && thisLayerJson.copyrightText.length > 0 ?
thisLayerJson.copyrightText : mapServerJson.copyrightText;
updateInfoSection(this, overwrite, 'Copyright Text', copyrightText);
};
function maximumScaleToLevel(maximumScale) {
if (!defined(maximumScale) || maximumScale <= 0.0) {
return undefined;
}
var dpi = 96; // Esri default DPI, unless we specify otherwise.
var centimetersPerInch = 2.54;
var centimetersPerMeter = 100;
var dotsPerMeter = dpi * centimetersPerMeter / centimetersPerInch;
var tileWidth = 256;
var circumferenceAtEquator = 2 * Math.PI * Ellipsoid.WGS84.maximumRadius;
var distancePerPixelAtLevel0 = circumferenceAtEquator / tileWidth;
var level0ScaleDenominator = distancePerPixelAtLevel0 * dotsPerMeter;
// 1e-6 epsilon from WMS 1.3.0 spec, section 7.2.4.6.9.
var ratio = level0ScaleDenominator / (maximumScale - 1e-6);
var levelAtMinScaleDenominator = Math.log(ratio) / Math.log(2);
return levelAtMinScaleDenominator | 0;
}
function getRectangleFromLayer(thisLayerJson) {
var extent = thisLayerJson.extent;
if (defined(extent) && extent.spatialReference && extent.spatialReference.wkid) {
var wkid = 'EPSG:' + extent.spatialReference.wkid;
if (!defined(proj4definitions[wkid])) {
return undefined;
}
var source = new proj4.Proj(proj4definitions[wkid]);
var dest = new proj4.Proj('EPSG:4326');
var p = proj4(source, dest, [extent.xmin, extent.ymin]);
var west = p[0];
var south = p[1];
p = proj4(source, dest, [extent.xmax, extent.ymax]);
var east = p[0];
var north = p[1];
return Rectangle.fromDegrees(west, south, east, north);
}
return undefined;
}
function getRectangleFromLayers(layers) {
if (!Array.isArray(layers)) {
return getRectangleFromLayer(layers);
}
return unionRectangleArray(layers.map(function(item) {
return getRectangleFromLayer(item);
}));
}
function updateInfoSection(item, overwrite, sectionName, sectionValue) {
if (!defined(sectionValue) || sectionValue.length === 0) {
return;
}
var section = item.findInfoSection(sectionName);
if (!defined(section)) {
item.info.push({
name: sectionName,
content: sectionValue
});
} else if (overwrite) {
section.content = sectionValue;
}
}
function updateValue(item, overwrite, propertyName, propertyValue) {
if (!defined(propertyValue)) {
return;
}
if (overwrite || !defined(item[propertyName])) {
item[propertyName] = propertyValue;
}
}
function getDataCustodian(mapServerJson) {
if (mapServerJson && mapServerJson.documentInfo && mapServerJson.documentInfo.Author && mapServerJson.documentInfo.Author.length > 0) {
return mapServerJson.documentInfo.Author;
}
return undefined;
}
function cleanAndProxyUrl(catalogItem, url) {
return proxyCatalogItemUrl(catalogItem, cleanUrl(url));
}
function cleanUrl(url) {
// Strip off the search portion of the URL
var uri = new URI(url);
uri.search('');
return uri.toString();
}
function requestMetadata(item) {
var result = new Metadata();
result.isLoading = true;
result.promise = when(item.load()).then(function() {
populateMetadataGroup(result.serviceMetadata, item._mapServerData);
if (!defined(item.layers)) {
result.dataSourceErrorMessage = 'Using all layers from this service that are visible by default. See the Service Details below.';
} else if (defined(item._thisLayerInLayersData)) {
populateMetadataGroup(result.dataSourceMetadata, item._thisLayerInLayersData);
} else {
result.dataSourceErrorMessage = 'No details are available.';
}
result.isLoading = false;
}).otherwise(function() {
result.dataSourceErrorMessage = 'An error occurred while invoking the ArcGIS map service.';
result.serviceErrorMessage = 'An error occurred while invoking the ArcGIS map service.';
result.isLoading = false;
});
return result;
}
function populateMetadataGroup(metadataGroup, sourceMetadata) {
if (typeof sourceMetadata === 'string' || sourceMetadata instanceof String) {
return;
}
if (sourceMetadata instanceof Array && (sourceMetadata.length === 0 || typeof sourceMetadata[0] !== 'object')) {
return;
}
for (var name in sourceMetadata) {
if (sourceMetadata.hasOwnProperty(name)) {
var value = sourceMetadata[name];
var dest = new MetadataItem();
dest.name = name;
dest.value = value;
populateMetadataGroup(dest, value);
metadataGroup.items.push(dest);
}
}
}
function findLayer(layers, id) {
id = id.toString();
var idLowerCase = id.toLowerCase();
var foundByName;
for (var i = 0; i < layers.length; ++i) {
var layer = layers[i];
if (layer.id.toString() === id) {
return layer;
} else if (layer.name.toLowerCase() === idLowerCase) {
foundByName = layer;
}
}
return foundByName;
}
/* Given a comma-separated string of layer names, returns the layer objects corresponding to them. */
function findLayers(layers, names) {
if (!defined(names)) {
// If a list of layers is not specified, we're using all layers.
return layers;
}
return names.split(',').map(function(id) {
return findLayer(layers, id);
});
}
function getLayerList(catalogItem) {
if (catalogItem._allLayersInLayersData && catalogItem._allLayersInLayersData.length > 0) {
var layers = [];
for (var i = 0; i < catalogItem._allLayersInLayersData.length; ++i) {
if (defined(catalogItem._allLayersInLayersData[i]) && defined(catalogItem._allLayersInLayersData[i].id)) {
layers.push(catalogItem._allLayersInLayersData[i].id.toString());
}
}
return layers.join(',');
} else {
return catalogItem.layers;
}
}
// Load a data URI and wait for it to load, returning an item. All of this is because data URI's don't load instantly,
// and we need to load the image in order to pass its dimensions.
// Alternative solution: just hardcode 26x26.
function loadImage(title, imageURI) {
var img = new Image();
img.src = imageURI;
var deferred = when.defer();
img.onload = deferred.resolve;
return deferred.promise.then(function() {
return {
title: title,
image: img,
imageUrl: imageURI,
imageWidth: img.width,
imageHeight: img.height
};
});
}
var labelsRegex = /_Labels$/;
/**
* Turns JSON into a LegendUrl.
* @param {Object} json JSON retrieved from server.
* @return {Promise}
*/
ArcGisMapServerCatalogItem.prototype.loadLegendFromJson = function(json) {
var options = {title: ''};
var layers = !defined(this.layers) ? [] : this.layers.toLowerCase().split(',');
var itemPromises = [];
var shownLegends = {};
json.layers.forEach(function(l) {
if (noDataRegex.test(l.layerName) || labelsRegex.test(l.layerName)) {
return;
}
if (defined(this.layers) && layers.indexOf(String(l.layerId)) < 0 && layers.indexOf(l.layerName.toLowerCase()) < 0) {
return;
}
options.title = replaceUnderscores(l.layerName);
l.legend.forEach(function(leg) {
if (shownLegends[leg.label + leg.imageData]) {
// Hide truly duplicate layers.
return;
}
shownLegends[leg.label + leg.imageData] = true;
var title = leg.label !== '' ? leg.label : l.layerName;
itemPromises.push(loadImage(replaceUnderscores(title), 'data:' + leg.contentType + ';base64,' + leg.imageData));
}, this);
}, this);
var that = this;
if (itemPromises.length === 0) {
return;
}
return when.all(itemPromises).then(function(items) {
items.reverse();
options.items = items;
return (that._generatedLegendUrl = new Legend(options).getLegendUrl());
}).otherwise(function(error) {
throw error;
});
};
module.exports = ArcGisMapServerCatalogItem;