dygraph-options.js

   1 /**
   2  * @license
   3  * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
   4  * MIT-licensed (http://opensource.org/licenses/MIT)
   5  */
   6
   7 /**
   8  * @fileoverview DygraphOptions is responsible for parsing and returning information about options.
   9  *
  10  * Still tightly coupled to Dygraphs, we could remove some of that, you know.
  11  */
  12
  13 var DygraphOptions = (function() {
  14
  15 /*jshint sub:true */
  16 /*global Dygraph:false */
  17 "use strict";
  18
  19 /*
  20  * Interesting member variables: (REMOVING THIS LIST AS I CLOSURIZE)
  21  * global_ - global attributes (common among all graphs, AIUI)
  22  * user - attributes set by the user
  23  * series_ - { seriesName -> { idx, yAxis, options }}
  24  */
  25
  26 /**
  27  * This parses attributes into an object that can be easily queried.
  28  *
  29  * It doesn't necessarily mean that all options are available, specifically
  30  * if labels are not yet available, since those drive details of the per-series
  31  * and per-axis options.
  32  *
  33  * @param {Dygraph} dygraph The chart to which these options belong.
  34  * @constructor
  35  */
  36 var DygraphOptions = function(dygraph) {
  37   /**
  38    * The dygraph.
  39    * @type {!Dygraph}
  40    */
  41   this.dygraph_ = dygraph;
  42
  43   /**
  44    * Array of axis index to { series : [ series names ] , options : { axis-specific options. }
  45    * @type {Array.<{series : Array.<string>, options : Object}>} @private
  46    */
  47   this.yAxes_ = [];
  48
  49   /**
  50    * Contains x-axis specific options, which are stored in the options key.
  51    * This matches the yAxes_ object structure (by being a dictionary with an
  52    * options element) allowing for shared code.
  53    * @type {options: Object} @private
  54    */
  55   this.xAxis_ = {};
  56   this.series_ = {};
  57
  58   // Once these two objects are initialized, you can call get();
  59   this.global_ = this.dygraph_.attrs_;
  60   this.user_ = this.dygraph_.user_attrs_ || {};
  61
  62   /**
  63    * A list of series in columnar order.
  64    * @type {Array.<string>}
  65    */
  66   this.labels_ = [];
  67
  68   this.highlightSeries_ = this.get("highlightSeriesOpts") || {};
  69   this.reparseSeries();
  70 };
  71
  72 /**
  73  * Not optimal, but does the trick when you're only using two axes.
  74  * If we move to more axes, this can just become a function.
  75  *
  76  * @type {Object.<number>}
  77  * @private
  78  */
  79 DygraphOptions.AXIS_STRING_MAPPINGS_ = {
  80   'y' : 0,
  81   'Y' : 0,
  82   'y1' : 0,
  83   'Y1' : 0,
  84   'y2' : 1,
  85   'Y2' : 1
  86 };
  87
  88 /**
  89  * @param {string|number} axis
  90  * @private
  91  */
  92 DygraphOptions.axisToIndex_ = function(axis) {
  93   if (typeof(axis) == "string") {
  94     if (DygraphOptions.AXIS_STRING_MAPPINGS_.hasOwnProperty(axis)) {
  95       return DygraphOptions.AXIS_STRING_MAPPINGS_[axis];
  96     }
  97     throw "Unknown axis : " + axis;
  98   }
  99   if (typeof(axis) == "number") {
 100     if (axis === 0 || axis === 1) {
 101       return axis;
 102     }
 103     throw "Dygraphs only supports two y-axes, indexed from 0-1.";
 104   }
 105   if (axis) {
 106     throw "Unknown axis : " + axis;
 107   }
 108   // No axis specification means axis 0.
 109   return 0;
 110 };
 111
 112 /**
 113  * Reparses options that are all related to series. This typically occurs when
 114  * options are either updated, or source data has been made available.
 115  *
 116  * TODO(konigsberg): The method name is kind of weak; fix.
 117  */
 118 DygraphOptions.prototype.reparseSeries = function() {
 119   var labels = this.get("labels");
 120   if (!labels) {
 121     return; // -- can't do more for now, will parse after getting the labels.
 122   }
 123
 124   this.labels_ = labels.slice(1);
 125
 126   this.yAxes_ = [ { series : [], options : {}} ]; // Always one axis at least.
 127   this.xAxis_ = { options : {} };
 128   this.series_ = {};
 129
 130   // Traditionally, per-series options were specified right up there with the options. For instance
 131   // {
 132   //   labels: [ "X", "foo", "bar" ],
 133   //   pointSize: 3,
 134   //   foo : {}, // options for foo
 135   //   bar : {} // options for bar
 136   // }
 137   //
 138   // Moving forward, series really should be specified in the series element, separating them.
 139   // like so:
 140   //
 141   // {
 142   //   labels: [ "X", "foo", "bar" ],
 143   //   pointSize: 3,
 144   //   series : {
 145   //     foo : {}, // options for foo
 146   //     bar : {} // options for bar
 147   //   }
 148   // }
 149   //
 150   // So, if series is found, it's expected to contain per-series data, otherwise we fall
 151   // back.
 152   var oldStyleSeries = !this.user_["series"];
 153
 154   if (oldStyleSeries) {
 155     var axisId = 0; // 0-offset; there's always one.
 156     // Go through once, add all the series, and for those with {} axis options, add a new axis.
 157     for (var idx = 0; idx < this.labels_.length; idx++) {
 158       var seriesName = this.labels_[idx];
 159
 160       var optionsForSeries = this.user_[seriesName] || {};
 161
 162       var yAxis = 0;
 163       var axis = optionsForSeries["axis"];
 164       if (typeof(axis) == 'object') {
 165         yAxis = ++axisId;
 166         this.yAxes_[yAxis] = { series : [ seriesName ], options : axis };
 167       }
 168
 169       // Associate series without axis options with axis 0.
 170       if (!axis) { // undefined
 171         this.yAxes_[0].series.push(seriesName);
 172       }
 173
 174       this.series_[seriesName] = { idx: idx, yAxis: yAxis, options : optionsForSeries };
 175     }
 176
 177     // Go through one more time and assign series to an axis defined by another
 178     // series, e.g. { 'Y1: { axis: {} }, 'Y2': { axis: 'Y1' } }
 179     for (var idx = 0; idx < this.labels_.length; idx++) {
 180       var seriesName = this.labels_[idx];
 181       var optionsForSeries = this.series_[seriesName]["options"];
 182       var axis = optionsForSeries["axis"];
 183
 184       if (typeof(axis) == 'string') {
 185         if (!this.series_.hasOwnProperty(axis)) {
 186           Dygraph.error("Series " + seriesName + " wants to share a y-axis with " +
 187                      "series " + axis + ", which does not define its own axis.");
 188           return;
 189         }
 190         var yAxis = this.series_[axis].yAxis;
 191         this.series_[seriesName].yAxis = yAxis;
 192         this.yAxes_[yAxis].series.push(seriesName);
 193       }
 194     }
 195   } else {
 196     for (var idx = 0; idx < this.labels_.length; idx++) {
 197       var seriesName = this.labels_[idx];
 198       var optionsForSeries = this.user_.series[seriesName] || {};
 199       var yAxis = DygraphOptions.axisToIndex_(optionsForSeries["axis"]);
 200
 201       this.series_[seriesName] = {
 202         idx: idx,
 203         yAxis: yAxis,
 204         options : optionsForSeries };
 205
 206       if (!this.yAxes_[yAxis]) {
 207         this.yAxes_[yAxis] =  { series : [ seriesName ], options : {} };
 208       } else {
 209         this.yAxes_[yAxis].series.push(seriesName);
 210       }
 211     }
 212   }
 213
 214   var axis_opts = this.user_["axes"] || {};
 215   Dygraph.update(this.yAxes_[0].options, axis_opts["y"] || {});
 216   if (this.yAxes_.length > 1) {
 217     Dygraph.update(this.yAxes_[1].options, axis_opts["y2"] || {});
 218   }
 219   Dygraph.update(this.xAxis_.options, axis_opts["x"] || {});
 220 };
 221
 222 /**
 223  * Get a global value.
 224  *
 225  * @param {string} name the name of the option.
 226  */
 227 DygraphOptions.prototype.get = function(name) {
 228   var result = this.getGlobalUser_(name);
 229   if (result !== null) {
 230     return result;
 231   }
 232   return this.getGlobalDefault_(name);
 233 };
 234
 235 DygraphOptions.prototype.getGlobalUser_ = function(name) {
 236   if (this.user_.hasOwnProperty(name)) {
 237     return this.user_[name];
 238   }
 239   return null;
 240 };
 241
 242 DygraphOptions.prototype.getGlobalDefault_ = function(name) {
 243   if (this.global_.hasOwnProperty(name)) {
 244     return this.global_[name];
 245   }
 246   if (Dygraph.DEFAULT_ATTRS.hasOwnProperty(name)) {
 247     return Dygraph.DEFAULT_ATTRS[name];
 248   }
 249   return null;
 250 };
 251
 252 /**
 253  * Get a value for a specific axis. If there is no specific value for the axis,
 254  * the global value is returned.
 255  *
 256  * @param {string} name the name of the option.
 257  * @param {string|number} axis the axis to search. Can be the string representation
 258  * ("y", "y2") or the axis number (0, 1).
 259  */
 260 DygraphOptions.prototype.getForAxis = function(name, axis) {
 261   var axisIdx;
 262   var axisString;
 263
 264   // Since axis can be a number or a string, straighten everything out here.
 265   if (typeof(axis) == 'number') {
 266     axisIdx = axis;
 267     axisString = axisIdx === 0 ? "y" : "y2";
 268   } else {
 269     if (axis == "y1") { axis = "y"; } // Standardize on 'y'. Is this bad? I think so.
 270     if (axis == "y") {
 271       axisIdx = 0;
 272     } else if (axis == "y2") {
 273       axisIdx = 1;
 274     } else if (axis == "x") {
 275       axisIdx = -1; // simply a placeholder for below.
 276     } else {
 277       throw "Unknown axis " + axis;
 278     }
 279     axisString = axis;
 280   }
 281
 282   var userAxis = (axisIdx == -1) ? this.xAxis_ : this.yAxes_[axisIdx];
 283
 284   // Search the user-specified axis option first.
 285   if (userAxis) { // This condition could be removed if we always set up this.yAxes_ for y2.
 286     var axisOptions = userAxis.options;
 287     if (axisOptions.hasOwnProperty(name)) {
 288       return axisOptions[name];
 289     }
 290   }
 291
 292   // User-specified global options second.
 293   // But, hack, ignore globally-specified 'logscale' for 'x' axis declaration.
 294   if (!(axis === 'x' && name === 'logscale')) {
 295     var result = this.getGlobalUser_(name);
 296     if (result !== null) {
 297       return result;
 298     }
 299   }
 300   // Default axis options third.
 301   var defaultAxisOptions = Dygraph.DEFAULT_ATTRS.axes[axisString];
 302   if (defaultAxisOptions.hasOwnProperty(name)) {
 303     return defaultAxisOptions[name];
 304   }
 305
 306   // Default global options last.
 307   return this.getGlobalDefault_(name);
 308 };
 309
 310 /**
 311  * Get a value for a specific series. If there is no specific value for the series,
 312  * the value for the axis is returned (and afterwards, the global value.)
 313  *
 314  * @param {string} name the name of the option.
 315  * @param {string} series the series to search.
 316  */
 317 DygraphOptions.prototype.getForSeries = function(name, series) {
 318   // Honors indexes as series.
 319   if (series === this.dygraph_.getHighlightSeries()) {
 320     if (this.highlightSeries_.hasOwnProperty(name)) {
 321       return this.highlightSeries_[name];
 322     }
 323   }
 324
 325   if (!this.series_.hasOwnProperty(series)) {
 326     throw "Unknown series: " + series;
 327   }
 328
 329   var seriesObj = this.series_[series];
 330   var seriesOptions = seriesObj["options"];
 331   if (seriesOptions.hasOwnProperty(name)) {
 332     return seriesOptions[name];
 333   }
 334
 335   return this.getForAxis(name, seriesObj["yAxis"]);
 336 };
 337
 338 /**
 339  * Returns the number of y-axes on the chart.
 340  * @return {number} the number of axes.
 341  */
 342 DygraphOptions.prototype.numAxes = function() {
 343   return this.yAxes_.length;
 344 };
 345
 346 /**
 347  * Return the y-axis for a given series, specified by name.
 348  */
 349 DygraphOptions.prototype.axisForSeries = function(series) {
 350   return this.series_[series].yAxis;
 351 };
 352
 353 /**
 354  * Returns the options for the specified axis.
 355  */
 356 // TODO(konigsberg): this is y-axis specific. Support the x axis.
 357 DygraphOptions.prototype.axisOptions = function(yAxis) {
 358   return this.yAxes_[yAxis].options;
 359 };
 360
 361 /**
 362  * Return the series associated with an axis.
 363  */
 364 DygraphOptions.prototype.seriesForAxis = function(yAxis) {
 365   return this.yAxes_[yAxis].series;
 366 };
 367
 368 /**
 369  * Return the list of all series, in their columnar order.
 370  */
 371 DygraphOptions.prototype.seriesNames = function() {
 372   return this.labels_;
 373 };
 374
 375 return DygraphOptions;
 376
 377 })();