dygraph-options.js

   1 /**
   2  * @fileoverview DygraphOptions is responsible for parsing and returning information about options.
   3  *
   4  * Still tightly coupled to Dygraphs, we could remove some of that, you know.
   5  */
   6
   7 "use strict";
   8
   9 /*
  10  * Interesting member variables:
  11  * dygraph_ - the graph.
  12  * global_ - global attributes (common among all graphs, AIUI)
  13  * user - attributes set by the user
  14  * axes_ - array of axis index to { series : [ series names ] , options : { axis-specific options. }
  15  * series_ - { seriesName -> { idx, yAxis, options }}
  16  * labels_ - used as mapping from index to series name.
  17  */
  18
  19 /**
  20  * This parses attributes into an object that can be easily queried.
  21  *
  22  * It doesn't necessarily mean that all options are available, specifically
  23  * if labels are not yet available, since those drive details of the per-series
  24  * and per-axis options.
  25  *
  26  * @param {Dyraph} dygraph The chart to which these options belong.
  27  * @constructor
  28  */
  29 var DygraphOptions = function(dygraph) {
  30   this.dygraph_ = dygraph;
  31   this.axes_ = [];
  32   this.series_ = {};
  33
  34   // Once these two objects are initialized, you can call get();
  35   this.global_ = this.dygraph_.attrs_;
  36   this.user_ = this.dygraph_.user_attrs_ || {};
  37
  38   this.highlightSeries_ = this.get("highlightSeriesOpts") || {};
  39   // Get a list of series names.
  40
  41   var labels = this.get("labels");
  42   if (!labels) {
  43     return; // -- can't do more for now, will parse after getting the labels.
  44   }
  45
  46   this.reparseSeries();
  47 };
  48
  49 /*
  50  * Not optimal, but does the trick when you're only using two axes.
  51  * If we move to more axes, this can just become a function.
  52  */
  53 DygraphOptions.AXIS_STRING_MAPPINGS_ = {
  54   'y' : 0,
  55   'Y' : 0,
  56   'y1' : 0,
  57   'Y1' : 0,
  58   'y2' : 1,
  59   'Y2' : 1
  60 };
  61
  62 DygraphOptions.axisToIndex_ = function(axis) {
  63   if (typeof(axis) == "string") {
  64     if (DygraphOptions.AXIS_STRING_MAPPINGS_.hasOwnProperty(axis)) {
  65       return DygraphOptions.AXIS_STRING_MAPPINGS_[axis];
  66     }
  67     throw "Unknown axis : " + axis;
  68   }
  69   if (typeof(axis) == "number") {
  70     if (axis === 0 || axis === 1) {
  71       return axis;
  72     }
  73     throw "Dygraphs only supports two y-axes, indexed from 0-1.";
  74   }
  75   if (typeof(axis) == "object") {
  76     throw "Using objects for axis specification "
  77       + "is not supported inside the 'series' option.";
  78   }
  79   if (axis) {
  80     throw "Unknown axis : " + axis;
  81   }
  82   // No axis specification means axis 0.
  83   return 0;
  84 };
  85
  86 /**
  87  * Reparses options that are all related to series. This typically occurs when
  88  * options are either updated, or source data has been made avaialble.
  89  *
  90  * TODO(konigsberg): The method name is kind of weak; fix.
  91  */
  92 DygraphOptions.prototype.reparseSeries = function() {
  93   this.labels = this.get("labels").slice(1);
  94
  95   this.axes_ = [ { series : [], options : {}} ]; // Always one axis at least.
  96   this.series_ = {};
  97
  98   // Traditionally, per-series options were specified right up there with the options. For instance
  99   // {
 100   //   labels: [ "X", "foo", "bar" ],
 101   //   pointSize: 3,
 102   //   foo : {}, // options for foo
 103   //   bar : {} // options for bar
 104   // }
 105   //
 106   // Moving forward, series really should be specified in the series element, separating them.
 107   // like so:
 108   //
 109   // {
 110   //   labels: [ "X", "foo", "bar" ],
 111   //   pointSize: 3,
 112   //   series : {
 113   //     foo : {}, // options for foo
 114   //     bar : {} // options for bar
 115   //   }
 116   // }
 117   //
 118   // So, if series is found, it's expected to contain per-series data, otherwise we fall
 119   // back.
 120   var oldStyleSeries = !this.user_["series"];
 121
 122   if (oldStyleSeries) {
 123     var axisId = 0; // 0-offset; there's always one.
 124     // Go through once, add all the series, and for those with {} axis options, add a new axis.
 125     for (var idx = 0; idx < this.labels.length; idx++) {
 126       var seriesName = this.labels[idx];
 127
 128       var optionsForSeries = this.user_[seriesName] || {};
 129
 130       var yAxis = 0;
 131       var axis = optionsForSeries["axis"];
 132       if (typeof(axis) == 'object') {
 133         yAxis = ++axisId;
 134         this.axes_[yAxis] = { series : [ seriesName ], options : axis };
 135       }
 136
 137       // Associate series without axis options with axis 0.
 138       if (!axis) { // undefined
 139         this.axes_[0].series.push(seriesName);
 140       }
 141
 142       this.series_[seriesName] = { idx: idx, yAxis: yAxis, options : optionsForSeries };
 143     }
 144
 145     // Go through one more time and assign series to an axis defined by another
 146     // series, e.g. { 'Y1: { axis: {} }, 'Y2': { axis: 'Y1' } }
 147     for (var idx = 0; idx < this.labels.length; idx++) {
 148       var seriesName = this.labels[idx];
 149       var optionsForSeries = this.series_[seriesName]["options"];
 150       var axis = optionsForSeries["axis"];
 151
 152       if (typeof(axis) == 'string') {
 153         if (!this.series_.hasOwnProperty(axis)) {
 154           this.dygraph_.error("Series " + seriesName + " wants to share a y-axis with " +
 155                      "series " + axis + ", which does not define its own axis.");
 156           return null;
 157         }
 158         var yAxis = this.series_[axis].yAxis;
 159         this.series_[seriesName].yAxis = yAxis;
 160         this.axes_[yAxis].series.push(seriesName);
 161       }
 162     }
 163   } else {
 164     for (var idx = 0; idx < this.labels.length; idx++) {
 165       var seriesName = this.labels[idx];
 166       var optionsForSeries = this.user_.series[seriesName] || {};
 167       var yAxis = DygraphOptions.axisToIndex_(optionsForSeries["axis"]);
 168
 169       this.series_[seriesName] = {
 170         idx: idx,
 171         yAxis: yAxis,
 172         options : optionsForSeries };
 173
 174       if (!this.axes_[yAxis]) {
 175         this.axes_[yAxis] =  { series : [ seriesName ], options : {} };
 176       } else {
 177         this.axes_[yAxis].series.push(seriesName);
 178       }
 179     }
 180   }
 181
 182   // This doesn't support reading from the 'x' axis, only 'y' and 'y2.
 183   var axis_opts = this.user_["axes"] || {};
 184   Dygraph.update(this.axes_[0].options, axis_opts["y"] || {});
 185   if (this.axes_.length > 1) {
 186     Dygraph.update(this.axes_[1].options, axis_opts["y2"] || {});
 187   }
 188 };
 189
 190 /**
 191  * Get a global value.
 192  *
 193  * @param {String} name the name of the option.
 194  */
 195 DygraphOptions.prototype.get = function(name) {
 196   if (this.user_.hasOwnProperty(name)) {
 197     return this.user_[name];
 198   }
 199   if (this.global_.hasOwnProperty(name)) {
 200     return this.global_[name];
 201   }
 202   return null;
 203 };
 204
 205 /**
 206  * Get a value for a specific axis. If there is no specific value for the axis,
 207  * the global value is returned.
 208  *
 209  * @param {String} name the name of the option.
 210  * @param {String|number} axis the axis to search. Can be the string representation
 211  * ("y", "y2") or the axis number (0, 1).
 212  */
 213 DygraphOptions.prototype.getForAxis = function(name, axis) {
 214   var axisIdx = 0;
 215   if (typeof(axis) == 'number') {
 216     axisIdx = axis;
 217   } else {
 218     // TODO(konigsberg): Accept only valid axis strings?
 219     axisIdx = (axis == "y2") ? 1 : 0;
 220   }
 221
 222   var axisOptions = this.axes_[axisIdx].options;
 223   if (axisOptions.hasOwnProperty(name)) {
 224     return axisOptions[name];
 225   }
 226   return this.get(name);
 227 };
 228
 229 /**
 230  * Get a value for a specific series. If there is no specific value for the series,
 231  * the value for the axis is returned (and afterwards, the global value.)
 232  *
 233  * @param {String} name the name of the option.
 234  * @param {String|number} series the series to search. Can be the string representation
 235  * or 0-offset series number.
 236  */
 237 DygraphOptions.prototype.getForSeries = function(name, series) {
 238   // Honors indexes as series.
 239   var seriesName = (typeof(series) == "number") ? this.labels[series] : series;
 240
 241   if (seriesName === this.dygraph_.highlightSet_) {
 242     if (this.highlightSeries_.hasOwnProperty(name)) {
 243       return this.highlightSeries_[name];
 244     }
 245   }
 246
 247   if (!this.series_.hasOwnProperty(seriesName)) {
 248     throw "Unknown series: " + series;
 249   }
 250
 251   var seriesObj = this.series_[seriesName];
 252   var seriesOptions = seriesObj["options"];
 253   if (seriesOptions.hasOwnProperty(name)) {
 254     return seriesOptions[name];
 255   }
 256
 257   return this.getForAxis(name, seriesObj["yAxis"]);
 258 };
 259
 260 /**
 261  * Returns the number of y-axes on the chart.
 262  * @return {Number} the number of axes.
 263  */
 264 DygraphOptions.prototype.numAxes = function() {
 265   return this.axes_.length;
 266 };
 267
 268 /**
 269  * Return the y-axis for a given series, specified by name.
 270  */
 271 DygraphOptions.prototype.axisForSeries = function(seriesName) {
 272   return this.series_[seriesName].yAxis;
 273 };
 274
 275 /**
 276  * Returns the options for the specified axis.
 277  */
 278 DygraphOptions.prototype.axisOptions = function(yAxis) {
 279   return this.axes_[yAxis].options;
 280 };
 281
 282 /**
 283  * Return the series associated with an axis.
 284  */
 285 DygraphOptions.prototype.seriesForAxis = function(yAxis) {
 286   return this.axes_[yAxis].series;
 287 };
 288
 289 /**
 290  * Return the list of all series, in their columnar order.
 291  */
 292 DygraphOptions.prototype.seriesNames = function() {
 293   return this.labels_;
 294 };
 295
 296 /* Are we using this? */
 297 /**
 298  * Return the index of the specified series.
 299  * @param {string} series the series name.
 300  */
 301 DygraphOptions.prototype.indexOfSeries = function(series) {
 302   return this.series_[series].idx;
 303 };