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