In order to simulate real-time chart updates (i.e. horizontal animation), it's necessary to distinguish a removed or added value from a simple update. The dataset controller now hooks array methods that alter the data array length to synchronize metadata accordingly. Also remove the duplicate calls of updateBezierControlPoints() for line and radar charts.
Responsiveness is currently based on the use of an iframe, however this method causes performance issues and could be troublesome when used with ad blockers. So make sure that the user is still able to create a chart without iframe when responsive is false.
For convenience, charts are now automatically released after each spec if they are not acquired using `persistent: true`. Also remove the confusing and error prone `chartInstance` global variable and make sure that chart instances are local to each spec.
Add "onHover" to the legend options that will hold a user defined function (default is null) and called when a "mousemove" event is registered on top of a label item, with same parameters as the "onClick" option.
Also introduced logic that determines if the type of event passed to the legend "handleEvent" function is one we can handle. Currently allowing "click" and "mousemove" events. If the event is not one of those we stop the function execution (this is for the sake of reusing the legend hitbox calculations).
When dealing with time-delineated datasets, often we have data for known
intervals of time. For example, we may have a dataset which represents number
of purchases per day:
```json
{
labels: ['2016-01-01', '2016-01-02', '2016-01-03']
datasets: [
{
data: [12, 87, 42]
}
],
'...': '...'
}
```
In this case, Chart.js will attempt to figure out the best interval to display
the data, and could pick `hours` as the unit. However, in this case, we would
prefer to just use the `days` interval since our data's granularity can not be
represented well with `hours`.
To remedy this, this commit adds the `minUnit` option which allows
users to (optionally) specify what the minimum unit they would like
to use.
Change the linter in gulp tasks to be consistent with Code Climate results which are based on ESLint using .eslintrc options. However, defaults Code Climate rules are too strict, so turn as warnings the 'complexity' and 'max-statements' rules (other errors has been fixed). Note that the Gulp task name has been changed for `gulp lint`.
Zooming in can cause the params `datasetIndex` and `index` to be null in method `getLabelMoment`. This happens when no ticks are visible on scale. It also throws an error and the chart becomes broken.
* Added borderDash support for grid lines (#3136)
* Save and restore context to prevent border dash being applied to other elements
* Adds support for borderDashOffset, checks for setLineDash (IE9/IE10)
* Fixes tests
Previously, calling getLabelMoment with an out of bound index would cause an
error such as this:
```
Uncaught TypeError: Cannot read property 'null' of undefined
```
This happens because there is not always guaranteed to be a labelMoment on
at the current datasetIndex.
One example of this is practice comes from a this function call:
```js
// since the are not always guaranteed to be at least two labelMoments
// \ / this index can be out of bounds
// |
var tickWidth = me.getPixelForTick(1) - me.getPixelForTick(0) - 6;
```
This patch simply ensures that the `labelMoments` for the `datasetIndex` are
defined before accessing properties on it.
* Category scale can now read from the xLabels and yLabels properties.
* Update docs with section regarding the data object.
* Add sample file with non numeric Y and fix animations
