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  * 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_ = [ { series : [], options : {}} ]; // Always one axis at least.
  59   this.series_ = {};
  60
  61   var axisId = 0; // 0-offset; there's always one.
  62   // Go through once, add all the series, and for those with {} axis options, add a new axis.
  63   for (var idx = 0; idx < this.labels.length; idx++) {
  64     var seriesName = this.labels[idx];
  65
  66     var optionsForSeries = this.user_[seriesName] || {};
  67     var yAxis = 0;
  68
  69     var axis = optionsForSeries["axis"];
  70     if (typeof(axis) == 'object') {
  71       yAxis = ++axisId;
  72       this.axes_[yAxis] = { series : [ seriesName ], options : axis };
  73     }
  74
  75     // Associate series without axis options with axis 0.
  76     if (!axis) { // undefined
  77       this.axes_[0].series.push(seriesName);
  78     }
  79
  80     this.series_[seriesName] = { idx: idx, yAxis: yAxis, options : optionsForSeries };
  81   }
  82
  83   // Go through one more time and assign series to an axis defined by another
  84   // series, e.g. { 'Y1: { axis: {} }, 'Y2': { axis: 'Y1' } }
  85   for (var idx = 0; idx < this.labels.length; idx++) {
  86     var seriesName = this.labels[idx];
  87     var optionsForSeries = this.series_[seriesName]["options"];
  88     var axis = optionsForSeries["axis"];
  89
  90     if (typeof(axis) == 'string') {
  91       if (!this.series_.hasOwnProperty(axis)) {
  92         this.dygraph_.error("Series " + seriesName + " wants to share a y-axis with " +
  93                    "series " + axis + ", which does not define its own axis.");
  94         return null;
  95       }
  96       var yAxis = this.series_[axis].yAxis;
  97       this.series_[seriesName].yAxis = yAxis;
  98       this.axes_[yAxis].series.push(seriesName);
  99     }
 100   }
 101
 102   // This doesn't support reading from the 'x' axis, only 'y' and 'y2.
 103   // Read from the global "axes" option.
 104   if (this.user_.hasOwnProperty("axes")) {
 105     var axis_opts = this.user_.axes;
 106
 107     if (axis_opts.hasOwnProperty("y")) {
 108       Dygraph.update(this.axes_[0].options, axis_opts.y);
 109     }
 110
 111     if (axis_opts.hasOwnProperty("y2")) {
 112       this.axes_[1] = this.axes_[1] || {}; // FIX
 113       Dygraph.update(this.axes_[1].options, axis_opts.y2);
 114     }
 115   }
 116 };
 117
 118 /**
 119  * Get a global value.
 120  *
 121  * @param {String} name the name of the option.
 122  */
 123 DygraphOptions.prototype.get = function(name) {
 124   if (this.user_.hasOwnProperty(name)) {
 125     return this.user_[name];
 126   }
 127   if (this.global_.hasOwnProperty(name)) {
 128     return this.global_[name];
 129   }
 130   return null;
 131 };
 132
 133 /**
 134  * Get a value for a specific axis. If there is no specific value for the axis,
 135  * the global value is returned.
 136  *
 137  * @param {String} name the name of the option.
 138  * @param {String|number} axis the axis to search. Can be the string representation
 139  * ("y", "y2") or the axis number (0, 1).
 140  */
 141 DygraphOptions.prototype.getForAxis = function(name, axis) {
 142   var axisIdx = 0;
 143   if (typeof(axis) == 'number') {
 144     axisIdx = axis;
 145   } else {
 146     // TODO(konigsberg): Accept only valid axis strings?
 147     axisIdx = (axis == "y2") ? 1 : 0;
 148   }
 149
 150   var axisOptions = this.axes_[axisIdx].options;
 151   if (axisOptions.hasOwnProperty(name)) {
 152     return axisOptions[name];
 153   }
 154   return this.get(name);
 155 };
 156
 157 /**
 158  * Get a value for a specific series. If there is no specific value for the series,
 159  * the value for the axis is returned (and afterwards, the global value.)
 160  *
 161  * @param {String} name the name of the option.
 162  * @param {String|number} series the series to search. Can be the string representation
 163  * or 0-offset series number.
 164  */
 165 DygraphOptions.prototype.getForSeries = function(name, series) {
 166   // Honors indexes as series.
 167   var seriesName = (typeof(series) == "number") ? this.labels[series] : series;
 168
 169   if (seriesName === this.dygraph_.highlightSet_) {
 170     if (this.highlightSeries_.hasOwnProperty(name)) {
 171       return this.highlightSeries_[name];
 172     }
 173   }
 174
 175   if (!this.series_.hasOwnProperty(seriesName)) {
 176     throw "Unknown series: " + series;
 177   }
 178
 179   var seriesObj = this.series_[seriesName];
 180   var seriesOptions = seriesObj["options"];
 181   if (seriesOptions.hasOwnProperty(name)) {
 182     return seriesOptions[name];
 183   }
 184
 185   return this.getForAxis(name, seriesObj["yAxis"]);
 186 };
 187
 188 /**
 189  * Returns the number of y-axes on the chart.
 190  * @return {Number} the number of axes.
 191  */
 192 DygraphOptions.prototype.numAxes = function() {
 193   return this.axes_.length;
 194 }
 195
 196 /**
 197  * Return the y-axis for a given series, specified by name.
 198  */
 199 DygraphOptions.prototype.axisForSeries = function(seriesName) {
 200   return this.series_[seriesName].yAxis;
 201 }
 202
 203 /**
 204  * Returns the options for the specified axis.
 205  */
 206 DygraphOptions.prototype.axisOptions = function(yAxis) {
 207   return this.axes_[yAxis].options;
 208 }
 209
 210 /**
 211  * Return the series associated with an axis.
 212  */
 213 DygraphOptions.prototype.seriesForAxis = function(yAxis) {
 214   return this.axes_[yAxis].series;
 215 }