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   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] = axis;
  73     }
  74     this.series_[seriesName] = { idx: idx, yAxis: yAxis, options : optionsForSeries };
  75   }
  76
  77   // Go through one more time and assign series to an axis defined by another
  78   // series, e.g. { 'Y1: { axis: {} }, 'Y2': { axis: 'Y1' } }
  79   for (var idx = 0; idx < this.labels.length; idx++) {
  80     var seriesName = this.labels[idx];
  81     var optionsForSeries = this.series_[seriesName]["options"];
  82     var axis = optionsForSeries["axis"];
  83
  84     if (typeof(axis) == 'string') {
  85       if (!this.series_.hasOwnProperty(axis)) {
  86         this.dygraph_.error("Series " + seriesName + " wants to share a y-axis with " +
  87                    "series " + axis + ", which does not define its own axis.");
  88         return null;
  89       }
  90       this.series_[seriesName].yAxis = this.series_[axis].yAxis;
  91     }
  92   }
  93
  94   // This doesn't support reading from the 'x' axis, only 'y' and 'y2.
  95   // Read from the global "axes" option.
  96   if (this.user_.hasOwnProperty("axes")) {
  97     var axis_opts = this.user_.axes;
  98
  99     if (axis_opts.hasOwnProperty("y")) {
 100       Dygraph.update(this.axes_[0], axis_opts.y);
 101     }
 102
 103     if (axis_opts.hasOwnProperty("y2")) {
 104       this.axes_[1] = this.axes_[1] || {};
 105       Dygraph.update(this.axes_[1], axis_opts.y2);
 106     }
 107   }
 108 };
 109
 110 /**
 111  * Get a global value.
 112  *
 113  * @param {String} name the name of the option.
 114  */
 115 DygraphOptions.prototype.get = function(name) {
 116   if (this.user_.hasOwnProperty(name)) {
 117     return this.user_[name];
 118   }
 119   if (this.global_.hasOwnProperty(name)) {
 120     return this.global_[name];
 121   }
 122   return null;
 123 };
 124
 125 /**
 126  * Get a value for a specific axis. If there is no specific value for the axis,
 127  * the global value is returned.
 128  *
 129  * @param {String} name the name of the option.
 130  * @param {String|number} axis the axis to search. Can be the string representation
 131  * ("y", "y2") or the axis number (0, 1).
 132  */
 133 DygraphOptions.prototype.getForAxis = function(name, axis) {
 134   var axisIdx = 0;
 135   if (typeof(axis) == 'number') {
 136     axisIdx = axis;
 137   } else {
 138     // TODO(konigsberg): Accept only valid axis strings?
 139     axisIdx = (axis == "y2") ? 1 : 0;
 140   }
 141
 142   var axisOptions = this.axes_[axisIdx];
 143   if (axisOptions.hasOwnProperty(name)) {
 144     return axisOptions[name];
 145   }
 146   return this.get(name);
 147 };
 148
 149 /**
 150  * Get a value for a specific series. If there is no specific value for the series,
 151  * the value for the axis is returned (and afterwards, the global value.)
 152  *
 153  * @param {String} name the name of the option.
 154  * @param {String|number} series the series to search. Can be the string representation
 155  * or 0-offset series number.
 156  */
 157 DygraphOptions.prototype.getForSeries = function(name, series) {
 158   // Honors indexes as series.
 159   var seriesName = (typeof(series) == "number") ? this.labels[series] : series;
 160
 161   if (seriesName === this.dygraph_.highlightSet_) {
 162     if (this.highlightSeries_.hasOwnProperty(name)) {
 163       return this.highlightSeries_[name];
 164     }
 165   }
 166
 167   if (!this.series_.hasOwnProperty(seriesName)) {
 168     throw "Unknown series: " + series;
 169   }
 170
 171   var seriesObj = this.series_[seriesName];
 172   var seriesOptions = seriesObj["options"];
 173   if (seriesOptions.hasOwnProperty(name)) {
 174     return seriesOptions[name];
 175   }
 176
 177   return this.getForAxis(name, seriesObj["yAxis"]);
 178 };
 179