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    * { options : { axis-specific options. } }
  51    * @type {Object} @private
  52    */
  53   this.xAxis_ = {};
  54   this.series_ = {};
  55
  56   // Once these two objects are initialized, you can call get();
  57   this.global_ = this.dygraph_.attrs_;
  58   this.user_ = this.dygraph_.user_attrs_ || {};
  59
  60   /**
  61    * A list of series in columnar order.
  62    * @type {Array.<string>}
  63    */
  64   this.labels_ = [];
  65
  66   this.highlightSeries_ = this.get("highlightSeriesOpts") || {};
  67   this.reparseSeries();
  68 };
  69
  70 /**
  71  * Not optimal, but does the trick when you're only using two axes.
  72  * If we move to more axes, this can just become a function.
  73  *
  74  * @type {Object.<string, number>}
  75  * @private
  76  */
  77 DygraphOptions.AXIS_STRING_MAPPINGS_ = {
  78   'y' : 0,
  79   'Y' : 0,
  80   'y1' : 0,
  81   'Y1' : 0,
  82   'y2' : 1,
  83   'Y2' : 1
  84 };
  85
  86 /**
  87  * @param {string|number} axis
  88  * @private
  89  */
  90 DygraphOptions.axisToIndex_ = function(axis) {
  91   if (typeof(axis) == "string") {
  92     if (DygraphOptions.AXIS_STRING_MAPPINGS_.hasOwnProperty(axis)) {
  93       return DygraphOptions.AXIS_STRING_MAPPINGS_[axis];
  94     }
  95     throw "Unknown axis : " + axis;
  96   }
  97   if (typeof(axis) == "number") {
  98     if (axis === 0 || axis === 1) {
  99       return axis;
 100     }
 101     throw "Dygraphs only supports two y-axes, indexed from 0-1.";
 102   }
 103   if (axis) {
 104     throw "Unknown axis : " + axis;
 105   }
 106   // No axis specification means axis 0.
 107   return 0;
 108 };
 109
 110 /**
 111  * Reparses options that are all related to series. This typically occurs when
 112  * options are either updated, or source data has been made available.
 113  *
 114  * TODO(konigsberg): The method name is kind of weak; fix.
 115  */
 116 DygraphOptions.prototype.reparseSeries = function() {
 117   var labels = this.get("labels");
 118   if (!labels) {
 119     return; // -- can't do more for now, will parse after getting the labels.
 120   }
 121
 122   this.labels_ = labels.slice(1);
 123
 124   this.yAxes_ = [ { series : [], options : {}} ]; // Always one axis at least.
 125   this.xAxis_ = { options : {} };
 126   this.series_ = {};
 127
 128   // Traditionally, per-series options were specified right up there with the options. For instance
 129   // {
 130   //   labels: [ "X", "foo", "bar" ],
 131   //   pointSize: 3,
 132   //   foo : {}, // options for foo
 133   //   bar : {} // options for bar
 134   // }
 135   //
 136   // Moving forward, series really should be specified in the series element, separating them.
 137   // like so:
 138   //
 139   // {
 140   //   labels: [ "X", "foo", "bar" ],
 141   //   pointSize: 3,
 142   //   series : {
 143   //     foo : {}, // options for foo
 144   //     bar : {} // options for bar
 145   //   }
 146   // }
 147   //
 148   // So, if series is found, it's expected to contain per-series data, otherwise we fall
 149   // back.
 150   var oldStyleSeries = !this.user_["series"];
 151
 152   if (oldStyleSeries) {
 153     var axisId = 0; // 0-offset; there's always one.
 154     // Go through once, add all the series, and for those with {} axis options, add a new axis.
 155     for (var idx = 0; idx < this.labels_.length; idx++) {
 156       var seriesName = this.labels_[idx];
 157
 158       var optionsForSeries = this.user_[seriesName] || {};
 159
 160       var yAxis = 0;
 161       var axis = optionsForSeries["axis"];
 162       if (typeof(axis) == 'object') {
 163         yAxis = ++axisId;
 164         this.yAxes_[yAxis] = { series : [ seriesName ], options : axis };
 165       }
 166
 167       // Associate series without axis options with axis 0.
 168       if (!axis) { // undefined
 169         this.yAxes_[0].series.push(seriesName);
 170       }
 171
 172       this.series_[seriesName] = { idx: idx, yAxis: yAxis, options : optionsForSeries };
 173     }
 174
 175     // Go through one more time and assign series to an axis defined by another
 176     // series, e.g. { 'Y1: { axis: {} }, 'Y2': { axis: 'Y1' } }
 177     for (var idx = 0; idx < this.labels_.length; idx++) {
 178       var seriesName = this.labels_[idx];
 179       var optionsForSeries = this.series_[seriesName]["options"];
 180       var axis = optionsForSeries["axis"];
 181
 182       if (typeof(axis) == 'string') {
 183         if (!this.series_.hasOwnProperty(axis)) {
 184           Dygraph.error("Series " + seriesName + " wants to share a y-axis with " +
 185                      "series " + axis + ", which does not define its own axis.");
 186           return;
 187         }
 188         var yAxis = this.series_[axis].yAxis;
 189         this.series_[seriesName].yAxis = yAxis;
 190         this.yAxes_[yAxis].series.push(seriesName);
 191       }
 192     }
 193   } else {
 194     for (var idx = 0; idx < this.labels_.length; idx++) {
 195       var seriesName = this.labels_[idx];
 196       var optionsForSeries = this.user_.series[seriesName] || {};
 197       var yAxis = DygraphOptions.axisToIndex_(optionsForSeries["axis"]);
 198
 199       this.series_[seriesName] = {
 200         idx: idx,
 201         yAxis: yAxis,
 202         options : optionsForSeries };
 203
 204       if (!this.yAxes_[yAxis]) {
 205         this.yAxes_[yAxis] =  { series : [ seriesName ], options : {} };
 206       } else {
 207         this.yAxes_[yAxis].series.push(seriesName);
 208       }
 209     }
 210   }
 211
 212   var axis_opts = this.user_["axes"] || {};
 213   Dygraph.update(this.yAxes_[0].options, axis_opts["y"] || {});
 214   if (this.yAxes_.length > 1) {
 215     Dygraph.update(this.yAxes_[1].options, axis_opts["y2"] || {});
 216   }
 217   Dygraph.update(this.xAxis_.options, axis_opts["x"] || {});
 218 };
 219
 220 /**
 221  * Get a global value.
 222  *
 223  * @param {string} name the name of the option.
 224  */
 225 DygraphOptions.prototype.get = function(name) {
 226   var result = this.getGlobalUser_(name);
 227   if (result !== null) {
 228     return result;
 229   }
 230   return this.getGlobalDefault_(name);
 231 };
 232
 233 DygraphOptions.prototype.getGlobalUser_ = function(name) {
 234   if (this.user_.hasOwnProperty(name)) {
 235     return this.user_[name];
 236   }
 237   return null;
 238 };
 239
 240 DygraphOptions.prototype.getGlobalDefault_ = function(name) {
 241   if (this.global_.hasOwnProperty(name)) {
 242     return this.global_[name];
 243   }
 244   if (Dygraph.DEFAULT_ATTRS.hasOwnProperty(name)) {
 245     return Dygraph.DEFAULT_ATTRS[name];
 246   }
 247   return null;
 248 };
 249
 250 /**
 251  * Get a value for a specific axis. If there is no specific value for the axis,
 252  * the global value is returned.
 253  *
 254  * @param {string} name the name of the option.
 255  * @param {string|number} axis the axis to search. Can be the string representation
 256  * ("y", "y2") or the axis number (0, 1).
 257  */
 258 DygraphOptions.prototype.getForAxis = function(name, axis) {
 259   var axisIdx;
 260   var axisString;
 261
 262   // Since axis can be a number or a string, straighten everything out here.
 263   if (typeof(axis) == 'number') {
 264     axisIdx = axis;
 265     axisString = axisIdx === 0 ? "y" : "y2";
 266   } else {
 267     if (axis == "y1") { axis = "y"; } // Standardize on 'y'. Is this bad? I think so.
 268     if (axis == "y") {
 269       axisIdx = 0;
 270     } else if (axis == "y2") {
 271       axisIdx = 1;
 272     } else if (axis == "x") {
 273       axisIdx = -1; // simply a placeholder for below.
 274     } else {
 275       throw "Unknown axis " + axis;
 276     }
 277     axisString = axis;
 278   }
 279
 280   var userAxis = (axisIdx == -1) ? this.xAxis_ : this.yAxes_[axisIdx];
 281
 282   // Search the user-specified axis option first.
 283   if (userAxis) { // This condition could be removed if we always set up this.yAxes_ for y2.
 284     var axisOptions = userAxis.options;
 285     if (axisOptions.hasOwnProperty(name)) {
 286       return axisOptions[name];
 287     }
 288   }
 289
 290   // User-specified global options second.
 291   var result = this.getGlobalUser_(name);
 292   if (result !== null) {
 293     return result;
 294   }
 295
 296   // Default axis options third.
 297   var defaultAxisOptions = Dygraph.DEFAULT_ATTRS.axes[axisString];
 298   if (defaultAxisOptions.hasOwnProperty(name)) {
 299     return defaultAxisOptions[name];
 300   }
 301
 302   // Default global options last.
 303   return this.getGlobalDefault_(name);
 304 };
 305
 306 /**
 307  * Get a value for a specific series. If there is no specific value for the series,
 308  * the value for the axis is returned (and afterwards, the global value.)
 309  *
 310  * @param {string} name the name of the option.
 311  * @param {string} series the series to search.
 312  */
 313 DygraphOptions.prototype.getForSeries = function(name, series) {
 314   // Honors indexes as series.
 315   if (series === this.dygraph_.getHighlightSeries()) {
 316     if (this.highlightSeries_.hasOwnProperty(name)) {
 317       return this.highlightSeries_[name];
 318     }
 319   }
 320
 321   if (!this.series_.hasOwnProperty(series)) {
 322     throw "Unknown series: " + series;
 323   }
 324
 325   var seriesObj = this.series_[series];
 326   var seriesOptions = seriesObj["options"];
 327   if (seriesOptions.hasOwnProperty(name)) {
 328     return seriesOptions[name];
 329   }
 330
 331   return this.getForAxis(name, seriesObj["yAxis"]);
 332 };
 333
 334 /**
 335  * Returns the number of y-axes on the chart.
 336  * @return {number} the number of axes.
 337  */
 338 DygraphOptions.prototype.numAxes = function() {
 339   return this.yAxes_.length;
 340 };
 341
 342 /**
 343  * Return the y-axis for a given series, specified by name.
 344  */
 345 DygraphOptions.prototype.axisForSeries = function(series) {
 346   return this.series_[series].yAxis;
 347 };
 348
 349 /**
 350  * Returns the options for the specified axis.
 351  */
 352 // TODO(konigsberg): this is y-axis specific. Support the x axis.
 353 DygraphOptions.prototype.axisOptions = function(yAxis) {
 354   return this.yAxes_[yAxis].options;
 355 };
 356
 357 /**
 358  * Return the series associated with an axis.
 359  */
 360 DygraphOptions.prototype.seriesForAxis = function(yAxis) {
 361   return this.yAxes_[yAxis].series;
 362 };
 363
 364 /**
 365  * Return the list of all series, in their columnar order.
 366  */
 367 DygraphOptions.prototype.seriesNames = function() {
 368   return this.labels_;
 369 };
 370
 371 /* Are we using this? */
 372 /**
 373  * Return the index of the specified series.
 374  * @param {string} series the series name.
 375  */
 376 DygraphOptions.prototype.indexOfSeries = function(series) {
 377   return this.series_[series].idx;
 378 };
 379
 380 return DygraphOptions;
 381
 382 })();