LoadCensusBlockTiles

query.js

/* Author: Albert Sun
   WSJ.com News Graphics
*/

/*jslint white: false, nomen: false, debug: false, devel: true, onevar: false, plusplus: false, browser: true, bitwise: false, es5: true, maxerr: 200 */
/*global jQuery: false, $: false, log: false, window: false, WSJNG: false, _: false, google: false, localStorage: false */

// Necessary functions
if (!window.typeOf) {
    window.typeOf = function(b){var a=typeof b;if(a==="object")if(b){if(b instanceof Array)a="array"}else a="null";return a};
}

// ***************************************
// Just in case there's a console.log hanging around....
// ***************************************
if (!window.console) { window.console = { "log": jQuery.noop }; }


// ***************************************
// Set up a Global Namespace
// ***************************************
var WSJNG = WSJNG || {};
WSJNG.query = WSJNG.query || {};



WSJNG.query.LoadCensusBlockTiles = (function() {
    var self = {};
    var loaded = new WSJNG.Dictionary();
    activexhr = [];

    self.setController = function(controller) {
        this.controller = controller;
    };

    self.handleDjangoResponse = function(data, textStatus, jqXHR) {
        var i, len, GEOID10, geom, info;
        var url = this.url.split(/\/|\./);
        var tile = [url[4], url[5], url[3]]; //[x,y,z]
        data = data.features;
        for (i=0, len=data.length; i<len; i++) {
            GEOID10 = data[i].id;
            geom = WSJNG.geom.ParseGeoJSONMultiPolygon(data[i].geometry.coordinates);
            
            if (data[i].properties !== undefined) {
                info = data[i].properties;
            }
            if (!WSJNG.Blocks[GEOID10]) {
                WSJNG.Blocks[GEOID10]= new WSJNG.Feature({"GEOID10": GEOID10, "multipolygon": geom, "fields": info, "map": WSJNG.map, "controller": self.controller});
                if (self.controller.SelectionController.containsFeature(GEOID10) === true) {
                    WSJNG.Blocks[GEOID10].selected = true;
                }
            }
            WSJNG.Blocks[GEOID10].tiles[tile.join("_")] = true;
        }
    };

    self.LoadTile = function(tile) {
        var key = "", xhrobj;
        key = tile.join("_");
        if (loaded[key] !== true) {
            xhrobj = $.getJSON("/geom/CensusBlockTile/"+tile[2]+"/"+tile[0]+"/"+tile[1]+".json")
                .complete(function(jqXHR, textStatus) {
                    for (var i=0, len=activexhr.length; i<len; i++) {
                        if (activexhr[i] === jqXHR) {
                            //console.log("removing xhr "+activexhr.length);
                            activexhr.splice(i,1);
                            return;
                        }
                    }
                });
            activexhr.push(xhrobj);
            $.when(xhrobj).then(
                this.handleDjangoResponse,
                (function(k) { return function() {
                    //fail handler: if the loadtile request fails, mark it as unloaded so we know to try again
                    loaded[k] = false;
                }; }(key))
            );
            loaded[key] = true;
        } else {
	    console.log('tile already loaded');
	}
    };

    self.RemoveTile = function(tilekey) {
	// 1. remove tileid from the query loaded object
	// 2. go through all blocks in the tile and remove self from them
	// 3. if a block that is getting the tile removed has no tiles remaining, remove it

	// loaded may not even be neccessary if google takes care of not requesting any tiles that have already been added
	// let's keep it for now anyways

	// it might be too slow to loop through all thousands of blocks every time a tile is unloaded
	// should save the GEOIDS associated with that tile with the tilekey for a quicker lookup
	

	loaded[tilekey] = false;
	var keys = WSJNG.Blocks.keys();
        for (var i=0,len=keys.length; i<len; i++) {
	    if (self.controller.SelectionController.containsFeature(keys[i]) !== true) {
		delete WSJNG.Blocks[keys[i]].tiles[tilekey];
		if (WSJNG.Blocks[keys[i]].tiles.length == 0) {
		    WSJNG.Blocks[keys[i]].remove();
		    delete WSJNG.Blocks[keys[i]];
		}
	    }
	}
    };

    /**
     * Remove all tiles from the map, except for selected ones
     */
    self.ReleaseBlocks = function() {
        $.when.apply(this, activexhr).always(function() {
            var counter = 0;
            var keys = WSJNG.Blocks.keys();
            for (var i=0,len=keys.length; i<len; i++) {
                if (self.controller.SelectionController.containsFeature(keys[i]) !== true) {
                    WSJNG.Blocks[keys[i]].remove();
                    delete WSJNG.Blocks[keys[i]];
                    counter++;
                }
            }
            loaded = new WSJNG.Dictionary();
            //console.log("removed "+counter+" blocks");
        });

        //console.log("aborting xhr "+activexhr.length);
         _.each(activexhr, function(el, i, list) {
             el.abort();
        });
    };

    return self;
}());