Handling data

Chart data in Vico is stored in ChartEntryModels, which you can create directly or indirectly. A FloatEntry holds data about a single entry on a chart (for example, a column). A ChartEntryModel contains one or more series (ChartEntry lists).

Static data

For static data, directly create a ChartEntryModel (for simple charts) or a ComposedChartEntryModel (for composed charts). A ChartEntryModel can be created via entryModelOf. entryOf creates a ChartEntry, and entriesOf creates a series. To create a ComposedChartEntryModel, combine ChartEntryModels via plus. To link a ChartEntryModel or ComposedChartEntryModel to a chart, use the model parameter of the Chart composable function, or the setModel function of BaseChartView.

Dynamic data

For dynamic data, use ChartEntryModelProducer (for simple charts) or ComposedChartEntryModelProducer (for composed charts).

ChartEntryModelProducer has a public constructor, which optionally takes the initial chart data. Call setEntries or setEntriesSuspending to update a ChartEntryModelProducer’s data.

In ComposedChartEntryModelProducers, data updates are handled via Transactions. As part of a Transaction, an initially empty list of data sets is created, and you can update it via the class’s functions (e.g., add or set). Notably, you can use populate to fill the new list of data sets with the current data. Each data set corresponds to a single nested Chart. To create a ComposedChartEntryModelProducer, use its build function, which lets you run an initial transaction. To run a data update, use runTransaction or runTransactionSuspending.

warning

Avoid the unnecessary recreation of ChartEntryModelProducers and ComposedChartEntryModelProducers. We recommend instantiating these classes in ViewModels. If you have to create an instance in a composable function, use remember. Never run data updates by recreating your ChartEntryModelProducer or ComposedChartEntryModelProducer.

To link a ChartEntryModelProducer or ComposedChartEntryModelProducer to a chart, use the chartModelProducer parameter of the Chart composable function, or the entryProducer field of BaseChartView.

Extras

Both ChartEntryModelProducer and ComposedChartEntryModelProducer let you define extras (auxiliary data). These can later be read via ChartEntryModel#extraStore. Extras are useful for properties that should change with the chart data and can’t be directly derived from it or should be precalculated. You can use them for lists of axis labels, for example. To add extras, use the updateExtras parameters of the setEntries and setEntriesSuspending functions of ChartEntryModelProducer, or, for ComposedChartEntryModelProducer, Transaction#updateExtras.