/* global define, console, Terraformer, shp, csv2geojson, RAMP, ArrayBuffer, Uint16Array */
/**
* @module RAMP
* @submodule DataLoader
* @main DataLoader
*/
/**
* A module for loading from web services and local files. Fetches data via File API (IE9 is currently not supported) or
* via XmlHttpRequest. Handles GeoJSON, Shapefiles and CSV currently. Includes utilities for parsing files into GeoJSON
* (currently the selected intermediate format) and converting GeoJSON into FeatureLayers for consumption by the ESRI JS
* API.
*
* ####Imports RAMP Modules:
* {{#crossLink "LayerLoader"}}{{/crossLink}}
* {{#crossLink "GlobalStorage"}}{{/crossLink}}
* {{#crossLink "Map"}}{{/crossLink}}
* {{#crossLink "Util"}}{{/crossLink}}
*
* @class DataLoader
* @static
* @uses dojo/Deferred
* @uses dojo/query
* @uses dojo/_base/array
* @uses esri/request
* @uses esri/SpatialReference
* @uses esri/layers/FeatureLayer
* @uses esri/renderers/SimpleRenderer
*/
define([
"dojo/Deferred", "dojo/query", "dojo/_base/array",
"esri/request", "esri/SpatialReference", "esri/layers/FeatureLayer", "esri/renderers/SimpleRenderer",
"ramp/layerLoader", "ramp/globalStorage", "ramp/map",
"utils/util"
],
function (
Deferred, query, dojoArray,
EsriRequest, SpatialReference, FeatureLayer, SimpleRenderer,
LayerLoader, GlobalStorage, RampMap,
Util
) {
"use strict";
/**
* Maps GeoJSON geometry types to a set of default renders defined in GlobalStorage.DefaultRenders
* @property featureTypeToRenderer {Object}
* @private
*/
var featureTypeToRenderer = {
Point: "circlePoint", MultiPoint: "circlePoint",
LineString: "solidLine", MultiLineString: "solidLine",
Polygon: "outlinedPoly", MultiPolygon: "outlinedPoly"
};
/**
* Loads a dataset using async calls, returns a promise which resolves with the dataset requested.
* Datasets may be loaded from URLs or via the File API and depending on the options will be loaded
* into a string or an ArrayBuffer.
*
* @param {Object} args Arguments object, should contain either {string} url or {File} file and optionally
* {string} type as "text" or "binary" (text by default)
* @returns {Promise} a Promise object resolving with either a {string} or {ArrayBuffer}
*/
function loadDataSet(args) {
var def = new Deferred(), promise;
if (args.file) {
if (args.url) {
throw new Error("Either url or file should be specified, not both");
}
if (args.type === "binary") {
promise = Util.readFileAsArrayBuffer(args.file);
} else {
promise = Util.readFileAsText(args.file);
}
promise.then(function (data) { def.resolve(data); }, function (error) { def.reject(error); });
} else if (args.url) {
try {
promise = (new EsriRequest({ url: args.url, handleAs: "text" })).promise;
} catch (e) {
def.reject(e);
}
promise.then(
function (data) {
// http://updates.html5rocks.com/2012/06/How-to-convert-ArrayBuffer-to-and-from-String
function str2ab(str) {
var buf = new ArrayBuffer(str.length * 2), // 2 bytes for each char
bufView = new Uint16Array(buf),
i = 0, j = 0, strLen = str.length, code;
while (i < strLen) {
// jshint bitwise:false
code = str.charCodeAt(i++);
if (code & 0xff00) {
bufView[j++] = (0xff00 & code) >> 8;
}
bufView[j++] = 0xff & code;
// jshint bitwise:true
}
return buf.slice(0,j);
}
if (args.type === 'binary') {
def.resolve(str2ab(data));
return;
}
def.resolve(data);
},
function (error) { def.reject(error); }
);
} else {
throw new Error("One of url or file should be specified");
}
return def.promise;
}
/**
* Fetch relevant data from a single feature layer endpoint. Returns a promise which
* resolves with a partial list of properties extracted from the endpoint.
*
* @param {string} featureLayerEndpoint a URL pointing to an ESRI Feature Layer
* @returns {Promise} a promise resolving with an object containing basic properties for the layer
*/
function getFeatureLayer(featureLayerEndpoint) {
var def = new Deferred(), promise;
try {
promise = (new EsriRequest({ url: featureLayerEndpoint + '?f=json' })).promise;
} catch (e) {
def.reject(e);
}
promise.then(
function (data) {
try {
var alias = {};
dojoArray.forEach(data.fields, function (field) {
alias[field.name] = field.alias;
});
var res = {
layerId: data.id, //TODO verifiy this. i think this is the index. we would want to use autoID?
layerName: data.name,
layerUrl: featureLayerEndpoint,
geometryType: data.geometryType,
fields: dojoArray.map(data.fields, function (x) { return x.name; }),
renderer: data.drawingInfo.renderer,
aliasMap: alias,
maxScale: data.maxScale,
minScale: data.minScale
};
def.resolve(res);
} catch (e) {
def.reject(e);
}
},
function (error) {
console.log(error);
def.reject(error);
}
);
return def.promise;
}
/**
* Fetch relevant data from a legend related to a feature layer endpoint. Returns a promise which
* resolves with a partial list of properties extracted from the endpoint.
*
* @param {string} featureLayerEndpoint a URL pointing to an ESRI Feature Layer
* @returns {Promise} a promise resolving with an object mapping legend labels to data URLs for those labels
*/
function getFeatureLayerLegend(featureLayerEndpoint) {
var def = new Deferred(), promise, legendUrl, idx, layerIdx;
//snip off last slash if there
idx = featureLayerEndpoint.indexOf('/', featureLayerEndpoint.length - 1);
if (idx > -1) {
legendUrl = featureLayerEndpoint.substring(0, idx - 1);
} else {
legendUrl = featureLayerEndpoint;
}
//snip off & store layer index, add legend to url
idx = legendUrl.lastIndexOf('/');
layerIdx = parseInt(legendUrl.substring(idx + 1));
legendUrl = legendUrl.substring(0, idx) + '/legend?f=json';
try {
promise = (new EsriRequest({ url: legendUrl })).promise;
} catch (e) {
def.reject(e);
}
promise.then(
function (data) {
//find our layer in the legend
var res = {};
dojoArray.forEach(data.layers, function (layer) {
if (layer.layerId === layerIdx) {
dojoArray.forEach(layer.legend, function (legendItem) {
res[legendItem.label] = "data:" + legendItem.contentType + ';base64,' + legendItem.imageData;
});
}
});
def.resolve(res);
},
function (error) {
console.log(error);
def.reject(error);
}
);
return def.promise;
}
/**
* Fetch layer data from a WMS endpoint. This method will execute a WMS GetCapabilities
* request against the specified URL, it requests WMS 1.3 and it is capable of parsing
* 1.3 or 1.1.1 responses. It returns a promise which will resolve with basic layer
* metadata and querying information.
*
* metadata response format:
* { queryTypes: [mimeType], layers: [{name, desc, queryable(bool)}] }
*
* @param {string} wmsEndpoint a URL pointing to a WMS server (it must not include a query string)
* @returns {Promise} a promise resolving with a metadata object (as specified above)
*/
function getWmsLayerList(wmsEndpoint) {
var def = new Deferred(), promise;
try {
promise = (new EsriRequest({ url: wmsEndpoint + '?service=WMS&version=1.3&request=GetCapabilities', handleAs: 'xml' })).promise;
} catch (e) {
def.reject(e);
}
// there might already be a way to do this in the parsing API
// I don't know XML parsing well enough (and I don't want to)
function getImmediateChild(node, childName) {
var i;
for (i = 0; i < node.childNodes.length; ++i) {
if (node.childNodes[i].nodeName === childName) {
return node.childNodes[i];
}
}
return undefined;
}
promise.then(
function (data) {
var layers, res = {};
try {
layers = dojoArray.map(query('Layer > Name', data), function (nameNode) { return nameNode.parentNode; });
res.layers = dojoArray.map(layers, function (x) {
var nameNode = getImmediateChild(x, 'Name'),
name = nameNode.textContent || nameNode.text,
// .text is for IE9's benefit, even though it claims to support .textContent
titleNode = getImmediateChild(x, 'Title');
return {
name: name,
desc: titleNode ? (titleNode.textContent || titleNode.text) : name,
queryable: x.getAttribute('queryable') === '1'
};
});
res.queryTypes = dojoArray.map(query('GetFeatureInfo > Format', data), function (node) { return node.textContent || node.text; });
} catch (e) {
def.reject(e);
}
def.resolve(res);
},
function (error) {
console.log(error);
def.reject(error);
}
);
return def.promise;
}
/**
* Performs in place assignment of integer ids for a GeoJSON FeatureCollection.
*/
function assignIds(geoJson) {
if (geoJson.type !== 'FeatureCollection') {
throw new Error("Assignment can only be performed on FeatureCollections");
}
dojoArray.forEach(geoJson.features, function (val, idx) {
if (typeof val.id === "undefined") {
val.id = idx;
}
});
}
/**
* Extracts fields from the first feature in the feature collection, does no
* guesswork on property types and calls everything a string.
*/
function extractFields(geoJson) {
if (geoJson.features.length < 1) {
throw new Error("Field extraction requires at least one feature");
}
return dojoArray.map(Object.keys(geoJson.features[0].properties), function (prop) {
return { name: prop, type: "esriFieldTypeString" };
});
}
/**
* Will generate a generic datagrid config node for a set of layer attributes.
*
* @param {Array} fields an array of attribute fields for a layer
* @param {Object} aliases optional param. a mapping of field names to field aliases
* @returns {Object} an JSON config object for feature datagrid
*/
function createDatagridConfig(fields, aliases) {
function makeField(id, fn, wd, ttl, tp) {
return {
id: id,
fieldName: fn,
width: wd,
orderable: false,
type: 'string',
alignment: 0,
title: ttl,
columnTemplate: tp
};
}
var dg = {
rowsPerPage: 50,
gridColumns: []
};
dg.gridColumns.push(makeField('iconCol', '', '50px', 'Icon', 'graphic_icon'));
dg.gridColumns.push(makeField('detailsCol', '', '60px', 'Details', 'details_button'));
dojoArray.forEach(fields, function (field, idx) {
if (field.toLowerCase() !== "shape") {
var fieldTitle = field;
if (aliases) {
if (aliases[field]) {
fieldTitle = aliases[field];
}
}
dg.gridColumns.push(makeField("col" + idx.toString(), field, '100px', fieldTitle, 'title_span'));
}
});
return dg;
}
/**
* Will generate a symbology config node for a ESRI feature service.
* Uses the information from the feature layers renderer JSON definition
*
* @param {Object} renderer renderer object from feature layer endpoint
* @param {Object} legendLookup object that maps legend label to data url of legend image
* @returns {Object} an JSON config object for feature symbology
*/
function createSymbologyConfig(renderer, legendLookup) {
var symb = {
type: renderer.type
};
switch (symb.type) {
case "simple":
symb.label = renderer.label;
symb.imageUrl = legendLookup[renderer.label];
break;
case "uniqueValue":
if (renderer.defaultLabel) {
symb.defaultImageUrl = legendLookup[renderer.defaultLabel];
}
symb.field1 = renderer.field1;
symb.field2 = renderer.field2;
symb.field3 = renderer.field3;
symb.valueMaps = dojoArray.map(renderer.uniqueValueInfos, function (uvi) {
return {
label: uvi.label,
value: uvi.value,
imageUrl: legendLookup[uvi.label]
};
});
break;
case "classBreaks":
if (renderer.defaultLabel) {
symb.defaultImageUrl = legendLookup[renderer.defaultLabel];
}
symb.field = renderer.field;
symb.minValue = renderer.minValue;
symb.rangeMaps = dojoArray.map(renderer.classBreakInfos, function (cbi) {
return {
label: cbi.label,
maxValue: cbi.classMaxValue,
imageUrl: legendLookup[cbi.label]
};
});
break;
default:
//Renderer we dont support
console.log('encountered unsupported renderer type: ' + symb.type);
//TODO make a stupid basic renderer to prevent things from breaking?
}
return symb;
}
/**
* Peek at the CSV output (useful for checking headers).
*
* @param {string} data a string containing the CSV (or any DSV) data
* @param {string} delimiter the delimiter used by the data, unlike other functions this will not guess a delimiter and
* this parameter is required
* @returns {Array} an array of arrays containing the parsed CSV
*/
function csvPeek(data, delimiter) {
return csv2geojson.dsv(delimiter).parseRows(data);
}
/**
* Converts a GeoJSON object into a FeatureLayer. Expects GeoJSON to be formed as a FeatureCollection
* containing a uniform feature type (FeatureLayer type will be set according to the type of the first
* feature entry). Accepts the following options:
* - renderer: a string identifying one of the properties in defaultRenders
* - sourceProjection: a string matching a proj4.defs projection to be used for the source data (overrides
* geoJson.crs)
* - targetWkid: an integer for an ESRI wkid, defaults to map wkid if not specified
* - fields: an array of fields to be appended to the FeatureLayer layerDefinition (OBJECTID is set by default)
*
* @method makeGeoJsonLayer
* @param {Object} geoJson An object following the GeoJSON specification, should be a FeatureCollection with
* Features of only one type
* @param {Object} opts An object for supplying additional parameters
* @returns {FeatureLayer} An ESRI FeatureLayer
*/
function makeGeoJsonLayer(geoJson, opts) {
var esriJson, layerDefinition, layer, fs, targetWkid, srcProj,
defaultRenderers = GlobalStorage.DefaultRenderers,
layerID = LayerLoader.nextId();
layerDefinition = {
objectIdField: "OBJECTID",
fields: [{
name: "OBJECTID",
type: "esriFieldTypeOID"
}]
};
targetWkid = RAMP.map.spatialReference.wkid;
assignIds(geoJson);
layerDefinition.drawingInfo = defaultRenderers[featureTypeToRenderer[geoJson.features[0].geometry.type]];
if (opts) {
if (opts.sourceProjection) {
srcProj = opts.sourceProjection;
}
if (opts.targetWkid) {
targetWkid = opts.targetWkid;
}
if (opts.fields) {
layerDefinition.fields = layerDefinition.fields.concat(opts.fields);
}
}
if (layerDefinition.fields.length === 1) {
layerDefinition.fields = layerDefinition.fields.concat(extractFields(geoJson));
}
console.log('reprojecting ' + srcProj + ' -> EPSG:' + targetWkid);
//console.log(geoJson);
Terraformer.Proj.convert(geoJson, 'EPSG:' + targetWkid, srcProj);
//console.log(geoJson);
esriJson = Terraformer.ArcGIS.convert(geoJson, { sr: targetWkid });
console.log('geojson -> esrijson converted');
//console.log(esriJson);
fs = { features: esriJson, geometryType: layerDefinition.drawingInfo.geometryType };
layer = new FeatureLayer({ layerDefinition: layerDefinition, featureSet: fs }, { mode: FeatureLayer.MODE_SNAPSHOT, id: layerID });
// ＼(｀O´)／ manually setting SR because it will come out as 4326
layer.spatialReference = new SpatialReference({ wkid: targetWkid });
// TODO : refactor the hack
// SZ_HACK
layer.renderer._RAMP_rendererType = featureTypeToRenderer[geoJson.features[0].geometry.type];
//SZ TESTING -- this will be removed when the UI separates the layer creation an layer enhancement
//enhanceFileFeatureLayer(layer, opts);
return layer;
}
/**
* Will take a feature layer built from user supplied data, and apply extra user options (such as symbology,
* display field), and generate a config node for the layer. Accepts the following options:
* - renderer: a string identifying one of the properties in defaultRenders
* - color: color of the renderer
* - icon: icon to display in grid and maptips
* - nameField: descriptive name field for the layer
* - datasetName: description of the name field
*
* @method enhanceFileFeatureLayer
* @param {Object} featureLayer a feature layer object generated by makeGeoJsonLayer
* @param {Object} opts An object for supplying additional parameters
*/
function enhanceFileFeatureLayer(featureLayer, opts) {
//make a minimal config object for this layer
var newConfig = {
id: featureLayer.id,
displayName: opts.datasetName,
nameField: opts.nameField,
symbology: {
type: "simple",
imageUrl: opts.icon
},
datagrid: createDatagridConfig(opts.fields)
},
defaultRenderers = GlobalStorage.DefaultRenderers;
//backfill the rest of the config object with default values
newConfig = GlobalStorage.applyFeatureDefaults(newConfig);
//add custom properties and event handlers to layer object
RampMap.enhanceLayer(featureLayer, newConfig, true);
featureLayer.ramp.type = GlobalStorage.layerType.feature; //TODO revisit
featureLayer.ramp.load.state = "loaded"; //because we made the feature layer by hand, it already has it's layer definition, so it begins in loaded state. the load event never fires
featureLayer.type = "Feature Layer"; //required to visible layer function
//plop config in global config object so everyone can access it.
RAMP.config.layers.feature.push(newConfig);
//apply new renderer if one is defined
if (opts.renderer && defaultRenderers.hasOwnProperty(opts.renderer)) {
var rend = defaultRenderers[opts.renderer].renderer;
if (opts.colour) {
rend.symbol.color = opts.colour;
}
featureLayer.renderer = new SimpleRenderer(rend);
} else if (opts.colour) { // change only color of the renderer
// SZ_HACK
featureLayer.renderer.symbol.color = opts.colour;
}
}
/**
* Constructs a FeatureLayer from CSV data.
* @param {string} csvData the CSV data to be processed
* @param {object} opts options to be set for the parser {string} latfield, {string} lonfield, {string} delimiter
* @returns {Promise} a promise resolving with a {FeatureLayer}
*/
function buildCsv(csvData, opts) {
var def = new Deferred(), csvOpts = { latfield: 'Lat', lonfield: 'Long', delimiter: ',' };
if (opts) {
if (opts.latfield) {
csvOpts.latfield = opts.latfield;
}
if (opts.lonfield) {
csvOpts.lonfield = opts.lonfield;
}
if (opts.delimiter) {
csvOpts.delimiter = opts.delimiter;
}
}
try {
csv2geojson.csv2geojson(csvData, csvOpts, function (err, data) {
var jsonLayer;
if (err) {
def.reject(err);
console.log("conversion error");
console.log(err);
return;
}
console.log('csv parsed');
console.log(data);
// csv2geojson will not include the lat and long in the feature
dojoArray.forEach(data.features, function (feature) {
// add new property Long and Lat before layer is generated
feature.properties[csvOpts.lonfield] = feature.geometry.coordinates[0];
feature.properties[csvOpts.latfield] = feature.geometry.coordinates[1];
});
jsonLayer = makeGeoJsonLayer(data, opts);
def.resolve(jsonLayer);
});
} catch (e) {
def.reject(e);
}
return def.promise;
}
/**
* Constructs a FeatureLayer from a Shapefile.
* @param {ArrayBuffer} shpData an ArrayBuffer of the Shapefile in zip format
* @returns {Promise} a promise resolving with a {FeatureLayer}
*/
function buildShapefile(shpData) {
var def = new Deferred();
try {
// window.crypto.subtle.digest({ name: "SHA-256" }, shpData).then(function (h) { var u8 = new Uint16Array(h); console.log(u8); });
shp.getShapefile(shpData).then(function (geojson) {
var jsonLayer;
try {
jsonLayer = makeGeoJsonLayer(geojson);
def.resolve(jsonLayer);
} catch (e) {
def.reject(e);
}
}, function (error) {
def.reject(error);
});
} catch (e) {
def.reject(e);
}
return def.promise;
}
/**
* Constructs a FeatureLayer from a GeoJSON string.
* This wraps makeGeoJsonLayer in an async wrapper, this is unnecessary but provides a consistent API.
* @param {string} jsonData a string containing the GeoJSON
* @returns {Promise} a promise resolving with a {FeatureLayer}
*/
function buildGeoJson(jsonData) {
var def = new Deferred(), jsonLayer = null;
try {
jsonLayer = makeGeoJsonLayer(JSON.parse(jsonData));
def.resolve(jsonLayer);
} catch (e) {
def.reject(e);
}
return def.promise;
}
return {
loadDataSet: loadDataSet,
getFeatureLayer: getFeatureLayer,
getFeatureLayerLegend: getFeatureLayerLegend,
getWmsLayerList: getWmsLayerList,
makeGeoJsonLayer: makeGeoJsonLayer,
csvPeek: csvPeek,
buildCsv: buildCsv,
buildShapefile: buildShapefile,
buildGeoJson: buildGeoJson,
enhanceFileFeatureLayer: enhanceFileFeatureLayer,
createDatagridConfig: createDatagridConfig,
createSymbologyConfig: createSymbologyConfig
};
});
Reusable Accessible Mapping Platform