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 - map of options specific to the axis.
  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 : " + text;
  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 (axis) {
  76     throw "Unknown axis : " + axis;
  77   }
  78   // No axis specification means axis 0.
  79   return 0;
  80 };
  81
  82 /**
  83  * Reparses options that are all related to series. This typically occurs when
  84  * options are either updated, or source data has been made avaialble.
  85  *
  86  * TODO(konigsberg): The method name is kind of weak; fix.
  87  */
  88 DygraphOptions.prototype.reparseSeries = function() {
  89   this.labels = this.get("labels").slice(1);
  90
  91   this.axes_ = [ {} ]; // Always one axis at least.
  92   this.series_ = {};
  93
  94   // Traditionally, per-series options were specified right up there with the options. For instance
  95   // {
  96   //   labels: [ "X", "foo", "bar" ],
  97   //   pointSize: 3,
  98   //   foo : {}, // options for foo
  99   //   bar : {} // options for bar
 100   // }
 101   //
 102   // Moving forward, series really should be specified in the series element, separating them.
 103   // like so:
 104   //
 105   // {
 106   //   labels: [ "X", "foo", "bar" ],
 107   //   pointSize: 3,
 108   //   series : {
 109   //     foo : {}, // options for foo
 110   //     bar : {} // options for bar
 111   //   }
 112   // }
 113   //
 114   // So, if series is found, it's expected to contain per-series data, otherwise we fall
 115   // back.
 116   var oldStyleSeries = !this.user_["series"];
 117
 118   if (oldStyleSeries) {
 119     var axisId = 0; // 0-offset; there's always one.
 120     // Go through once, add all the series, and for those with {} axis options, add a new axis.
 121     for (var idx = 0; idx < this.labels.length; idx++) {
 122       var seriesName = this.labels[idx];
 123
 124       var optionsForSeries = this.user_[seriesName] || {};
 125
 126       var yAxis = 0;
 127       var axis = optionsForSeries["axis"];
 128       if (typeof(axis) == 'object') {
 129         yAxis = ++axisId;
 130         this.axes_[yAxis] = axis;
 131       }
 132       this.series_[seriesName] = { idx: idx, yAxis: yAxis, options : optionsForSeries };
 133     }
 134
 135     // Go through one more time and assign series to an axis defined by another
 136     // series, e.g. { 'Y1: { axis: {} }, 'Y2': { axis: 'Y1' } }
 137     for (var idx = 0; idx < this.labels.length; idx++) {
 138       var seriesName = this.labels[idx];
 139       var optionsForSeries = this.series_[seriesName]["options"];
 140       var axis = optionsForSeries["axis"];
 141
 142       if (typeof(axis) == 'string') {
 143         if (!this.series_.hasOwnProperty(axis)) {
 144           this.dygraph_.error("Series " + seriesName + " wants to share a y-axis with " +
 145                      "series " + axis + ", which does not define its own axis.");
 146           return null;
 147         }
 148         this.series_[seriesName].yAxis = this.series_[axis].yAxis;
 149       }
 150     }
 151   } else {
 152     var maxYAxis = 0;
 153
 154     for (var idx = 0; idx < this.labels.length; idx++) {
 155       var seriesName = this.labels[idx];
 156       var optionsForSeries = this.user_.series[seriesName] || {};
 157       var yAxis = DygraphOptions.axisToIndex_(optionsForSeries["axis"]);
 158
 159       maxYAxis = Math.max(yAxis, maxYAxis);
 160
 161       this.series_[seriesName] = {
 162         idx: idx,
 163         yAxis: yAxis,
 164         options : optionsForSeries };
 165     }
 166
 167     for (; maxYAxis >= 0; maxYAxis--) {
 168       this.axes_[maxYAxis] = {};
 169     }
 170   }
 171
 172   // This doesn't support reading from the 'x' axis, only 'y' and 'y2.
 173   if (this.user_["axes"]) {
 174     var axis_opts = this.user_.axes;
 175
 176     if (axis_opts.hasOwnProperty("y")) {
 177       Dygraph.update(this.axes_[0], axis_opts.y);
 178     }
 179
 180     if (axis_opts.hasOwnProperty("y2")) {
 181       this.axes_[1] = this.axes_[1] || {};
 182       Dygraph.update(this.axes_[1], axis_opts.y2);
 183     }
 184   }
 185 };
 186
 187 /**
 188  * Get a global value.
 189  *
 190  * @param {String} name the name of the option.
 191  */
 192 DygraphOptions.prototype.get = function(name) {
 193   if (this.user_.hasOwnProperty(name)) {
 194     return this.user_[name];
 195   }
 196   if (this.global_.hasOwnProperty(name)) {
 197     return this.global_[name];
 198   }
 199   return null;
 200 };
 201
 202 /**
 203  * Get a value for a specific axis. If there is no specific value for the axis,
 204  * the global value is returned.
 205  *
 206  * @param {String} name the name of the option.
 207  * @param {String|number} axis the axis to search. Can be the string representation
 208  * ("y", "y2") or the axis number (0, 1).
 209  */
 210 DygraphOptions.prototype.getForAxis = function(name, axis) {
 211   var axisIdx = 0;
 212   if (typeof(axis) == 'number') {
 213     axisIdx = axis;
 214   } else {
 215     // TODO(konigsberg): Accept only valid axis strings?
 216     axisIdx = (axis == "y2") ? 1 : 0;
 217   }
 218
 219   var axisOptions = this.axes_[axisIdx];
 220   if (axisOptions.hasOwnProperty(name)) {
 221     return axisOptions[name];
 222   }
 223   return this.get(name);
 224 };
 225
 226 /**
 227  * Get a value for a specific series. If there is no specific value for the series,
 228  * the value for the axis is returned (and afterwards, the global value.)
 229  *
 230  * @param {String} name the name of the option.
 231  * @param {String|number} series the series to search. Can be the string representation
 232  * or 0-offset series number.
 233  */
 234 DygraphOptions.prototype.getForSeries = function(name, series) {
 235   // Honors indexes as series.
 236   var seriesName = (typeof(series) == "number") ? this.labels[series] : series;
 237
 238   if (seriesName === this.dygraph_.highlightSet_) {
 239     if (this.highlightSeries_.hasOwnProperty(name)) {
 240       return this.highlightSeries_[name];
 241     }
 242   }
 243
 244   if (!this.series_.hasOwnProperty(seriesName)) {
 245     throw "Unknown series: " + series;
 246   }
 247
 248   var seriesObj = this.series_[seriesName];
 249   var seriesOptions = seriesObj["options"];
 250   if (seriesOptions.hasOwnProperty(name)) {
 251     return seriesOptions[name];
 252   }
 253
 254   return this.getForAxis(name, seriesObj["yAxis"]);
 255 };