Add a new `offset` option to scales to add extra space at edges and remove the `includeOffset` argument from `getPixelForValue()` and `getPixelForTick()`. The bar controller now automatically calculates the bar width to avoid overlaps. When `offsetGridLines` is true, grid lines move to the left by one half of the tick interval, and labels don't move.
The `bounds` option makes more sense directly under `scale` since it defines the scale limits strategy when no explicit min/max are specified. Also change the `bounds: 'labels'` option value for `bounds: 'ticks'` because it really means: "ensure ticks to be fully visible in the scale, whatever the ticks `source`.
Fix `ticks.mode` behavior when `ticks.source` is `auto`: the lookup table is now built from the data and not from the ticks, so data (and ticks) are correctly distributed along the scale. Rename the option to `distribution` (more explicit than `mode`) and since this option applies from now on the data, it seems better to have it under `scale` instead `scale.ticks`.
Internal ticks are now stored as objects in the PRIVATE this._ticks member and must not be accessed directly from outside this class. this.ticks is around for a long time and hasn't been marked as private, so we can't change its structure without unexpected breaking changes. If you need to access the scale ticks, use scale.getTicks() instead.
`ticks.bounds` (`'data'`(default)|`'label'`): `data` preserves the data range while `labels` ensures that all labels are visible. This option is bypassed by the min/max time options.
Remove the useless time scale `_model` object containing private members: instead, make these members private (prefixed by `_`) part of the scale.
Move time helpers back into time scale, remove the `Chart.helpers.time namespace` and attempt to make the auto generation logic a bit simpler. The generate method doesn't anymore enforce min/max, the calling code needs to clamp timestamps if needed.
For time series charts it may make more sense to specify the horizontal axis using the variable `t`. This change will make it much easier to use the time scale with the financial chart, which takes in the data points `{t, o, h, l, c}`.
`ticks.source` (`'auto'`(default)|`'labels'`): `auto` generates "optimal" ticks based on min, max and a few more options (current `time` implementation`). `labels` generates ticks from the user given `data.labels` values (two additional trailing and leading ticks can be added if min and max are provided).
`ticks.mode` (`'linear'`(default)|`series`): `series` displays ticks at the same distance from each other, whatever the time value they represent, while `linear` displays them linearly in time: the distance between each tick represent the amount of time between their time values.
Default options can now be accessed by importing `core/core.defaults`. The returned object acts as a singleton and is populated when importing classes that expose their own default values (meaning that importing only `code.defaults` results in an empty object). Also make `Chart.Ticks` and `Chart.Interaction` importable since existing defaults rely on these values.
Add the `defaults._set` method that make easier declaring new defaults by merging given values with existing ones for a specific scope (`global`, `scale`, `bar`, etc).
Properly export helpers and remove dependencies to `Chart.helpers`. Helpers can now be accessed from `src/helpers/index.js` (`var helpers = require('path/to/helpers/index')`, instead of `var helpers = Chart.helpers`).
For consistency with `valueOrDefault`, `valueAtIndexOrDefault` now returns null if `value` (expected array) is null. Also get rid of the superfluous `get` prefix in `getValueOrDefault` and `getValueAtIndexOrDefault`.
Implemented alignment by major unit in the time scale. This allows showing the first tick of a larger unit like days in a special way and is part of the basis of the time series scale.
* Make parseTime private
* start on fixing time scale
* Reimplement existing functionality
* Tidy tests
* Fix labels for non-linearly sized units
Months, quarters and years have non-constant numbers of seconds. A scale that's linear WRT milliseconds produces incorrect tick labels due to the label formatting losing precision (eg year labels lose month and day so a label of 2016-12-32 displays as 2016 instead of 2017).
* Re-implement tick generation
As in v2.5
When datasets.data contains a null value, the label displays incorrect
value.
code additions:
- unit tests for truthy label values (when data is null)
- checks to ensure handling of null value in getLabelByIndex method
added mock data sets from issue #3528 example
expect the return value from getLabelForIndex method to be valid (truthy)
added check for null of first data value in getLabelForIndex
fixed indentation and null comparison operator in code
fixed mistake in definition of firstData variable
changed testing for data on index 0 to using index variable
changed firstData to use value instead
condense the statments to use value variable
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.
Previously buildLabelDiffs() was called at the end of buildTicks() and
hence labelDiffs cache was calculated twice (in getMinimumBoxSize() and
then in fitBox()).
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.
In case of charts with over 4000 points, smallestLabelSeparation
calculation contributes significantly to total cpu usage (about 25% according
to built-in Chrome profiler). Important thing to note is that result
of this calculation is not used at all.
Related commits:
* 677c249b613bf1a4ebccb1bebda9f04f7346b866
introduced smallestLabelSeparation. It was used in calculateBaseWidth
function.
* d198157fb8ea479ec9286bcf0ffb72e2e62e9661
removed last use of smallestLabelSeparation. Since then the calculated
value was never used.
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.
