* Early data parsing + stacking by value
* Review comments
* review comments
* Remove reduntant parsing
* Couple CC warnings
* Optimize filterBetween
* More migration info
Add functionality to give pie & doughnut datasets a weight attribute, which affects the relative thickness of the dataset when there are multiple datasets in pie & doughnut charts. The default weight of each dataset is 1, providing any other numerical value will allow the pie or doughnut dataset to be drawn with a thickness relative to its default size.
For example a weight of 2 will allow the dataset to be drawn double its typical dataset thickness. Note that the weight attribute will only affect a pie or doughnut chart if there is more than one visible dataset. Using weight on a pie or doughnut dataset when there is only one dataset on the chart will have no affect.
`controllers.*.js` and `core.datasetController.js` are now importable (no more function export), that's why there is so many changes mainly due to one indentation level removed. Split code for `bar/horizontalBar` and `doughnut/pie` in separate files, added a global controllers import (`src/controllers/index.js`) and add tests to check that all dataset controllers are correctly registered under `chart.controllers.{type}`.
For consistency, enable ESLint `one-var` rule to require multiple variable declarations for initialized variables per scope. Uninitialized variables can still be declared together (preferred) or separately.
http://eslint.org/docs/rules/one-var
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`.
Fixes a rendering issue when there are multiple datasets on a pie chart and they do not all contain the same number of data in their datasets
Fixes#3309
