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New `options.resolve` helper that determines the final value to use from an array of input values (fallback) and a given context and/or index. For now, only the bubble chart support scriptable options, see documentation for details. Add scriptable options documentation and update the bubble chart dataset properties table with their scriptable and indexable capabilities and default values. Also move point style description under the element configuration section.
46 lines
1.6 KiB
Markdown
46 lines
1.6 KiB
Markdown
# Options
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## Scriptable Options
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Scriptable options also accept a function which is called for each data and that takes the unique argument `context` representing contextual information (see [option context](options.md#option-context)).
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Example:
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```javascript
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color: function(context) {
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return context.data < 0 ? 'red' : // draw negative values in red
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index%2 ? 'blue' : 'green'; // else, alternate values in blue and green
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}
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```
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> **Note:** scriptable options are only supported by a few bubble chart options.
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## Indexable Options
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Indexable options also accept an array in which each item corresponds to the element at the same index. Note that this method requires to provide as many items as data, so, in most cases, using a [function](#scriptable-options) is more appropriated if supported.
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Example:
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```javascript
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color: [
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'red', // color for data at index 0
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'blue', // color for data at index 1
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'green', // color for data at index 2
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'black', // color for data at index 3
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//...
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]
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```
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## Option Context
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The option context is used to give contextual information when resolving options and currently only applies to [scriptable options](#scriptable-options).
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The context object contains the following properties:
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- `chart`: the associated chart
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- `dataIndex`: index of the current data
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- `dataset`: dataset at index `datasetIndex`
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- `datasetIndex`: index of the current dataset
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**Important**: since the context can represent different types of entities (dataset, data, etc.), some properties may be `undefined` so be sure to test any context property before using it.
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