File yui3/src/charts/js/TimeImpl.js
/**
* Provides functionality for the handling of time axis data for a chart.
*
* @module charts
* @submodule axis-time-base
*/
var Y_Lang = Y.Lang;
/**
* TimeImpl contains logic for time data. TimeImpl is used by the following classes:
* <ul>
* <li>{{#crossLink "TimeAxisBase"}}{{/crossLink}}</li>
* <li>{{#crossLink "TimeAxis"}}{{/crossLink}}</li>
* </ul>
*
* @class TimeImpl
* @constructor
* @submodule axis-time-base
*/
function TimeImpl()
{
}
TimeImpl.NAME = "timeImpl";
TimeImpl.ATTRS =
{
/**
* Method used for formatting a label. This attribute allows for the default label formatting method to overridden.
* The method use would need to implement the arguments below and return a `String` or an `HTMLElement`. The default
* implementation of the method returns a `String`. The output of this method will be rendered to the DOM using
* `appendChild`. If you override the `labelFunction` method and return an html string, you will also need to override
* the Axis' `appendLabelFunction` to accept html as a `String`.
* <dl>
* <dt>val</dt><dd>Label to be formatted. (`String`)</dd>
* <dt>format</dt><dd>STRFTime string used to format the label. (optional)</dd>
* </dl>
*
* @attribute labelFunction
* @type Function
*/
/**
* Pattern used by the `labelFunction` to format a label.
*
* @attribute labelFormat
* @type String
*/
labelFormat: {
value: "%b %d, %y"
}
};
TimeImpl.prototype = {
/**
* Type of data used in `Data`.
*
* @property _type
* @readOnly
* @private
*/
_type: "time",
/**
* Getter method for maximum attribute.
*
* @method _maximumGetter
* @return Number
* @private
*/
_maximumGetter: function ()
{
var max = this._getNumber(this._setMaximum);
if(!Y_Lang.isNumber(max))
{
max = this._getNumber(this.get("dataMaximum"));
}
return parseFloat(max);
},
/**
* Setter method for maximum attribute.
*
* @method _maximumSetter
* @param {Object} value
* @private
*/
_maximumSetter: function (value)
{
this._setMaximum = this._getNumber(value);
return value;
},
/**
* Getter method for minimum attribute.
*
* @method _minimumGetter
* @return Number
* @private
*/
_minimumGetter: function ()
{
var min = this._getNumber(this._setMinimum);
if(!Y_Lang.isNumber(min))
{
min = this._getNumber(this.get("dataMinimum"));
}
return parseFloat(min);
},
/**
* Setter method for minimum attribute.
*
* @method _minimumSetter
* @param {Object} value
* @private
*/
_minimumSetter: function (value)
{
this._setMinimum = this._getNumber(value);
return value;
},
/**
* Indicates whether or not the maximum attribute has been explicitly set.
*
* @method _getSetMax
* @return Boolean
* @private
*/
_getSetMax: function()
{
var max = this._getNumber(this._setMaximum);
return (Y_Lang.isNumber(max));
},
/**
* Indicates whether or not the minimum attribute has been explicitly set.
*
* @method _getSetMin
* @return Boolean
* @private
*/
_getSetMin: function()
{
var min = this._getNumber(this._setMinimum);
return (Y_Lang.isNumber(min));
},
/**
* Formats a label based on the axis type and optionally specified format.
*
* @method formatLabel
* @param {Object} value
* @param {Object} format Pattern used to format the value.
* @return String
*/
formatLabel: function(val, format)
{
val = Y.DataType.Date.parse(val);
if(format)
{
return Y.DataType.Date.format(val, {format:format});
}
return val;
},
/**
* Constant used to generate unique id.
*
* @property GUID
* @type String
* @private
*/
GUID: "yuitimeaxis",
/**
* Type of data used in `Axis`.
*
* @property _dataType
* @readOnly
* @private
*/
_dataType: "time",
/**
* Gets an array of values based on a key.
*
* @method _getKeyArray
* @param {String} key Value key associated with the data array.
* @param {Array} data Array in which the data resides.
* @return Array
* @private
*/
_getKeyArray: function(key, data)
{
var obj,
keyArray = [],
i = 0,
val,
len = data.length;
for(; i < len; ++i)
{
obj = data[i][key];
if(Y_Lang.isDate(obj))
{
val = obj.valueOf();
}
else
{
val = new Date(obj);
if(Y_Lang.isDate(val))
{
val = val.valueOf();
}
else if(!Y_Lang.isNumber(obj))
{
if(Y_Lang.isNumber(parseFloat(obj)))
{
val = parseFloat(obj);
}
else
{
if(typeof obj !== "string")
{
obj = obj;
}
val = new Date(obj).valueOf();
}
}
else
{
val = obj;
}
}
keyArray[i] = val;
}
return keyArray;
},
/**
* Calculates the maximum and minimum values for the `Axis`.
*
* @method _updateMinAndMax
* @private
*/
_updateMinAndMax: function()
{
var data = this.get("data"),
max = 0,
min = 0,
len,
num,
i;
if(data && data.length && data.length > 0)
{
len = data.length;
max = min = data[0];
if(len > 1)
{
for(i = 1; i < len; i++)
{
num = data[i];
if(isNaN(num))
{
continue;
}
max = Math.max(num, max);
min = Math.min(num, min);
}
}
}
this._dataMaximum = max;
this._dataMinimum = min;
},
/**
* Returns a coordinate corresponding to a data values.
*
* @method _getCoordFromValue
* @param {Number} min The minimum for the axis.
* @param {Number} max The maximum for the axis.
* @param {Number} length The distance that the axis spans.
* @param {Number} dataValue A value used to ascertain the coordinate.
* @param {Number} offset Value in which to offset the coordinates.
* @param {Boolean} reverse Indicates whether the coordinates should start from
* the end of an axis. Only used in the numeric implementation.
* @return Number
* @private
*/
_getCoordFromValue: function(min, max, length, dataValue, offset)
{
var range,
multiplier,
valuecoord,
isNumber = Y_Lang.isNumber;
dataValue = this._getNumber(dataValue);
if(isNumber(dataValue))
{
range = max - min;
multiplier = length/range;
valuecoord = (dataValue - min) * multiplier;
valuecoord = offset + valuecoord;
}
else
{
valuecoord = NaN;
}
return valuecoord;
},
/**
* Parses value into a number.
*
* @method _getNumber
* @param val {Object} Value to parse into a number
* @return Number
* @private
*/
_getNumber: function(val)
{
if(Y_Lang.isDate(val))
{
val = val.valueOf();
}
else if(!Y_Lang.isNumber(val) && val)
{
val = new Date(val).valueOf();
}
return val;
}
};
Y.TimeImpl = TimeImpl;