How to make a dynamic valueBox in Flexdashboards in R - r

Question

I'm trying to build a panel where when selecting a State in a drop-down list the value of a valueBox dynamically change according to the column value in the database, but in every attempt I get an error return. Below, the code used:
library(flexdashboard)
library(shiny)
UF = c('AC', 'AM', 'AP', 'BA', 'CE', 'ES', 'PB', 'PE')
Column = c(30, 200, 7, 12, 854, 2, 78, 965)
df <- data.frame(UF,Coluna)
Row {data-width=200 .sidebar}
--------------------------------------------------------------
{r}
selectInput(inputId = "states",
label="Select State:",
choices = unique(df$UF),
selected = "",
multiple=FALSE
)
Row
-----------------------------------------------------------------------
{r}
renderValueBox({
b <- df %>%
filter(UF %in% input$states) %>%
select(df$Column)
valueBox(value = b, icon = "fa-users")
})

Answer 1

It turns out you have a couple of mistakes here:
You have some misspelling of variable names.
You didn't load all the required libraries.
You had the wrong {dplyr} grammar for select.
After fixing everything, here is the working code:
---
title: "Untitled"
output:
flexdashboard::flex_dashboard:
orientation: columns
vertical_layout: fill
runtime: shiny
---
```{r}
library(flexdashboard)
library(shiny)
library(magrittr)
library(dplyr)
```
```{r}
UF = c('AC', 'AM', 'AP', 'BA', 'CE', 'ES', 'PB', 'PE')
Column = c(30, 200, 7, 12, 854, 2, 78, 965)
df <- data.frame(UF,Column)
```
Row {data-width=200 .sidebar}
--------------------------------------------------------------
```{r}
selectInput(inputId = "states",
label="Select State:",
choices = unique(df$UF),
selected = "",
multiple=FALSE
)
```
Row
-----------------------------------------------------------------------
```{r}
renderValueBox({
b <- df %>%
filter(UF %in% input$states) %>%
select(Column)
valueBox(value = b, icon = "fa-users")
})
```