Component Data

Data is used for a component's internal state and can also be used to pass information from a parent component to its children. Both component templates and methods have access to component data.

Details

Creating data

To create component data, define a function that returns a list of named objects. These objects can be Shiny reactive objects, data frames, lists, or any other R object.

For instance, the following is a valid data function:

function() {
 list(
   rctv = shiny::reactiveVal(),
   df   = mtcars
 )
}

Accessing data

Data can be accessed in both the methods and template parts of the component via the self keyword. For example, the following component defines the data foo, and accesses it in the template via self$foo.

x <- component(
    name = "data_access",
    data = function() {
        list(
            foo = 1L
        )
    },
    template = function(ns) {
        self$foo
    }
)

print(x())
#> <rsx::instance> `data_access`
#>   1

Passing data

To pass data to a component, use the data argument when calling the component function. The data argument should be a list of named objects that match the names of the objects defined in the component's data function. For example:

x <- component(
    name = "data_access",
    data = function() {
        list(
            foo = 1L
        )
    },
    template = function(ns) {
        self$foo
    }
)

print(x(data = list(foo = 2L)))
#> <rsx::instance> `data_access`
#>   2

See also

Other components: component-methods, component-styles, component-template, component()