How to assign row names to a reactive data frame in Shiny? - r

Question

I am trying to do something that is quite simple to achieve in R script but I am struggling to replicate when part of a Shiny app. I am reading a file using ‘reactive({})’ (this part in the test code provided below has been replaced with test dataset, lines 13-16). I would like to take variable ‘Species’ entries and assign them to the data frame row names. I have tried two approaches
Inside the “reactive({})” statement, lines 13-16
By creating a new data frame df1, lines 18-20
but both ways don’t work for some reason.
Big thank you in advance!
library(shiny)
library(DT)
library(datasets)
ui <- basicPage("",
DT::dataTableOutput("table"),
verbatimTextOutput("head1"),
verbatimTextOutput("head2")
)
server <- function(input, output, session) {
df <- reactive({
df <- data.frame(v1=c("a", "b"), v2=c(10,20))
# row.names(df) <- df[,1] # THIS DOES NOT WORK
})
df1 <- reactive({ # THIS ALSO DOESN'T WORK
row.names(df()) <- df()[,1]
})
# Show data in a table ----
output$table <- DT::renderDataTable({
datatable(
{df()},
filter = 'top',
class="cell-border stripe",
rownames = TRUE
) # end of datatable
})
output$head1 <- renderPrint({
head(df())
})
output$head2 <- renderPrint({
head(df1())
})
}
shinyApp(ui = ui, server = server)

Answer 1

Try this
library(shiny)
library(DT)
library(datasets)
ui <- basicPage("",
DTOutput("table"),
DTOutput("head1"),
DTOutput("head2")
)
server <- function(input, output, session) {
df <- reactive({
df <- data.frame(v1=c("a", "b"), v2=c(10,20))
row.names(df) <- df[,1] # THIS WORKs
df
})
df1 <- reactive({ # THIS ALSO WORKs
data <- df()
row.names(data) <- df()[,1]
data
})
# Show data in a table ----
output$table <- renderDT({
datatable(
{df()},
filter = 'top',
class="cell-border stripe",
rownames = TRUE
) # end of datatable
})
output$head1 <- renderDT({
head(df())
})
output$head2 <- renderDT({
head(df1())
})
}
shinyApp(ui = ui, server = server)