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  * Reparses options that are all related to series. This typically occurs when
  51  * options are either updated, or source data has been made avaialble.
  52  *
  53  * TODO(konigsberg): The method name is kind of weak; fix.
  54  */
  55 DygraphOptions.prototype.reparseSeries = function() {
  56   this.labels = this.get("labels").slice(1);
  57
  58   this.axes_ = [ {} ]; // Always one axis at least.
  59   this.series_ = {};
  60
  61   // Traditionally, per-series options were specified right up there with the options. For instance
  62   // {
  63   //   labels: [ "X", "foo", "bar" ],
  64   //   pointSize: 3,
  65   //   foo : {}, // options for foo
  66   //   bar : {} // options for bar
  67   // }
  68   //
  69   // Moving forward, series really should be specified in the series element, separating them.
  70   // like so:
  71   //
  72   // {
  73   //   labels: [ "X", "foo", "bar" ],
  74   //   pointSize: 3,
  75   //   series : {
  76   //     foo : {}, // options for foo
  77   //     bar : {} // options for bar
  78   //   }
  79   // }
  80   //
  81   // So, if series is found, it's expected to contain per-series data, otherwise we fall
  82   // back.
  83   var allseries = this.user_["series"] ? this.user_.series : this.user_;
  84
  85   var axisId = 0; // 0-offset; there's always one.
  86   // Go through once, add all the series, and for those with {} axis options, add a new axis.
  87   for (var idx = 0; idx < this.labels.length; idx++) {
  88     var seriesName = this.labels[idx];
  89
  90     var optionsForSeries = allseries[seriesName] || {};
  91     var yAxis = 0;
  92
  93     var axis = optionsForSeries["axis"];
  94     if (typeof(axis) == 'object') {
  95       yAxis = ++axisId;
  96       this.axes_[yAxis] = axis;
  97     }
  98     this.series_[seriesName] = { idx: idx, yAxis: yAxis, options : optionsForSeries };
  99   }
 100
 101   // Go through one more time and assign series to an axis defined by another
 102   // series, e.g. { 'Y1: { axis: {} }, 'Y2': { axis: 'Y1' } }
 103   for (var idx = 0; idx < this.labels.length; idx++) {
 104     var seriesName = this.labels[idx];
 105     var optionsForSeries = this.series_[seriesName]["options"];
 106     var axis = optionsForSeries["axis"];
 107
 108     if (typeof(axis) == 'string') {
 109       if (!this.series_.hasOwnProperty(axis)) {
 110         this.dygraph_.error("Series " + seriesName + " wants to share a y-axis with " +
 111                    "series " + axis + ", which does not define its own axis.");
 112         return null;
 113       }
 114       this.series_[seriesName].yAxis = this.series_[axis].yAxis;
 115     }
 116   }
 117
 118   // This doesn't support reading from the 'x' axis, only 'y' and 'y2.
 119   // Read from the global "axes" option.
 120   if (this.user_["axes"]) {
 121     var axis_opts = this.user_.axes;
 122
 123     if (axis_opts.hasOwnProperty("y")) {
 124       Dygraph.update(this.axes_[0], axis_opts.y);
 125     }
 126
 127     if (axis_opts.hasOwnProperty("y2")) {
 128       this.axes_[1] = this.axes_[1] || {};
 129       Dygraph.update(this.axes_[1], axis_opts.y2);
 130     }
 131   }
 132 };
 133
 134 /**
 135  * Get a global value.
 136  *
 137  * @param {String} name the name of the option.
 138  */
 139 DygraphOptions.prototype.get = function(name) {
 140   if (this.user_.hasOwnProperty(name)) {
 141     return this.user_[name];
 142   }
 143   if (this.global_.hasOwnProperty(name)) {
 144     return this.global_[name];
 145   }
 146   return null;
 147 };
 148
 149 /**
 150  * Get a value for a specific axis. If there is no specific value for the axis,
 151  * the global value is returned.
 152  *
 153  * @param {String} name the name of the option.
 154  * @param {String|number} axis the axis to search. Can be the string representation
 155  * ("y", "y2") or the axis number (0, 1).
 156  */
 157 DygraphOptions.prototype.getForAxis = function(name, axis) {
 158   var axisIdx = 0;
 159   if (typeof(axis) == 'number') {
 160     axisIdx = axis;
 161   } else {
 162     // TODO(konigsberg): Accept only valid axis strings?
 163     axisIdx = (axis == "y2") ? 1 : 0;
 164   }
 165
 166   var axisOptions = this.axes_[axisIdx];
 167   if (axisOptions.hasOwnProperty(name)) {
 168     return axisOptions[name];
 169   }
 170   return this.get(name);
 171 };
 172
 173 /**
 174  * Get a value for a specific series. If there is no specific value for the series,
 175  * the value for the axis is returned (and afterwards, the global value.)
 176  *
 177  * @param {String} name the name of the option.
 178  * @param {String|number} series the series to search. Can be the string representation
 179  * or 0-offset series number.
 180  */
 181 DygraphOptions.prototype.getForSeries = function(name, series) {
 182   // Honors indexes as series.
 183   var seriesName = (typeof(series) == "number") ? this.labels[series] : series;
 184
 185   if (seriesName === this.dygraph_.highlightSet_) {
 186     if (this.highlightSeries_.hasOwnProperty(name)) {
 187       return this.highlightSeries_[name];
 188     }
 189   }
 190
 191   if (!this.series_.hasOwnProperty(seriesName)) {
 192     throw "Unknown series: " + series;
 193   }
 194
 195   var seriesObj = this.series_[seriesName];
 196   var seriesOptions = seriesObj["options"];
 197   if (seriesOptions.hasOwnProperty(name)) {
 198     return seriesOptions[name];
 199   }
 200
 201   return this.getForAxis(name, seriesObj["yAxis"]);
 202 };
 203