src/datahandler/bars.js

   1 /**
   2  * @license
   3  * Copyright 2013 David Eberlein (david.eberlein@ch.sauter-bc.com)
   4  * MIT-licensed (http://opensource.org/licenses/MIT)
   5  */
   6
   7 /**
   8  * @fileoverview DataHandler base implementation for the "bar"
   9  * data formats. This implementation must be extended and the
  10  * extractSeries and rollingAverage must be implemented.
  11  * @author David Eberlein (david.eberlein@ch.sauter-bc.com)
  12  */
  13
  14 /*global Dygraph:false */
  15 /*global DygraphLayout:false */
  16 "use strict";
  17
  18 import DygraphDataHandler from './datahandler';
  19 import DygraphLayout from '../dygraph-layout';
  20
  21 /**
  22  * @constructor
  23  * @extends {Dygraph.DataHandler}
  24  */
  25 var BarsHandler = function() {
  26   DygraphDataHandler.call(this);
  27 };
  28 BarsHandler.prototype = new DygraphDataHandler();
  29
  30 // TODO(danvk): figure out why the jsdoc has to be copy/pasted from superclass.
  31 //   (I get closure compiler errors if this isn't here.)
  32 /**
  33  * @override
  34  * @param {!Array.<Array>} rawData The raw data passed into dygraphs where
  35  *     rawData[i] = [x,ySeries1,...,ySeriesN].
  36  * @param {!number} seriesIndex Index of the series to extract. All other
  37  *     series should be ignored.
  38  * @param {!DygraphOptions} options Dygraph options.
  39  * @return {Array.<[!number,?number,?]>} The series in the unified data format
  40  *     where series[i] = [x,y,{extras}].
  41  */
  42 BarsHandler.prototype.extractSeries = function(rawData, seriesIndex, options) {
  43   // Not implemented here must be extended
  44 };
  45
  46 /**
  47  * @override
  48  * @param {!Array.<[!number,?number,?]>} series The series in the unified
  49  *          data format where series[i] = [x,y,{extras}].
  50  * @param {!number} rollPeriod The number of points over which to average the data
  51  * @param {!DygraphOptions} options The dygraph options.
  52  * TODO(danvk): be more specific than "Array" here.
  53  * @return {!Array.<[!number,?number,?]>} the rolled series.
  54  */
  55 BarsHandler.prototype.rollingAverage =
  56     function(series, rollPeriod, options) {
  57   // Not implemented here, must be extended.
  58 };
  59
  60 /** @inheritDoc */
  61 BarsHandler.prototype.onPointsCreated_ = function(series, points) {
  62   for (var i = 0; i < series.length; ++i) {
  63     var item = series[i];
  64     var point = points[i];
  65     point.y_top = NaN;
  66     point.y_bottom = NaN;
  67     point.yval_minus = DygraphDataHandler.parseFloat(item[2][0]);
  68     point.yval_plus = DygraphDataHandler.parseFloat(item[2][1]);
  69   }
  70 };
  71
  72 /** @inheritDoc */
  73 BarsHandler.prototype.getExtremeYValues = function(series, dateWindow, options) {
  74   var minY = null, maxY = null, y;
  75
  76   var firstIdx = 0;
  77   var lastIdx = series.length - 1;
  78
  79   for ( var j = firstIdx; j <= lastIdx; j++) {
  80     y = series[j][1];
  81     if (y === null || isNaN(y)) continue;
  82
  83     var low = series[j][2][0];
  84     var high = series[j][2][1];
  85
  86     if (low > y) low = y; // this can happen with custom bars,
  87     if (high < y) high = y; // e.g. in tests/custom-bars.html
  88
  89     if (maxY === null || high > maxY) maxY = high;
  90     if (minY === null || low < minY) minY = low;
  91   }
  92
  93   return [ minY, maxY ];
  94 };
  95
  96 /** @inheritDoc */
  97 BarsHandler.prototype.onLineEvaluated = function(points, axis, logscale) {
  98   var point;
  99   for (var j = 0; j < points.length; j++) {
 100     // Copy over the error terms
 101     point = points[j];
 102     point.y_top = DygraphLayout.calcYNormal_(axis, point.yval_minus, logscale);
 103     point.y_bottom = DygraphLayout.calcYNormal_(axis, point.yval_plus, logscale);
 104   }
 105 };
 106
 107 export default BarsHandler;