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}`.
The title plugin and scale title now accept lineHeight specified using unitless value (1.4), length ('1.4em' or '12px'), percentage ('200%') or keyword ('normal' === 1.2). The line height parsing has been refactored under the 'Chart.helpers.options' namespace. Also fix incorrect text positioning in the title plugin.
https://developer.mozilla.org/en-US/docs/Web/CSS/line-height
`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`).
* Fix relative links in documentation of configurations
* Fix relative link of 'Time Units'
* Fix relative links for chart types documentations
* Fix the release version link in developers/plugins
The `clone` method now accepts any type of input but also recursively perform a deep copy of the array items. Rewrite the `configMerge` and `scaleMerge` helpers which now rely on a new generic and customizable `merge` method, that one accepts a target object in which multiple sources are deep copied. Note that the target (first argument) is not cloned and will be modified after calling `merge(target, sources)`. Add a `mergeIf` helper which merge the source properties only if they do not exist in the target object.
Raise the cyclomatic complexity to 10 which seems to better match the project coding style and still reasonable (6 being quite low). Also move unit tests specific eslint rules in the cascaded `./test/.eslintrc` file (previously in `gulp.js`).
Deprecate `addEvent` and `removeEvent`, and move implementation in `platform.dom.js`. Add 'options' feature detection to register event listeners as passive and prevent warning in Chrome.
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`.
Move some of the "core" and "canvas" utils in `helpers.core.js` and `helpers.canvas.js` and introduce the new `isNullOrUndef` and `isObject` helpers. Deprecate `indexOf` and rename `drawRoundedRectangle` to `roundedRect` which now creates a simple `rect` path if radius is 0. Write missing unit tests for the moved helpers.
Elements were resizing incorrectly if they were regenerated while the chart was in a div that was display:none. Added a check to avoid this issue. Resolves#4397
