In the following code I have two reactive functions, say A and B (which I want to control via an isolate function and two action buttons), but only A works at all. If I change the order of the functions (I mean, I first write B and then A), then B is the only one that works.
The program is reading and editing a postgreSQL database. Function B inserts a new line in the table. Function A deletes a line of the same table.
shinyServer(
function(input, output) {
pool <- dbPool(
drv = dbDriver("PostgreSQL", max.con = 100),
dbname = "postgres",
host = "localhost",
user = "postgres",
password = "123",
idleTimeout = 36000
)
# Show table in the ui #
output$view <- renderDataTable({
dbTable<-dbGetQuery(pool, "SELECT * FROM Table")
dbTable <- select(dbTable, name, lastname)
names(dbTable)<-c('Name', 'Lastname')
dbTable
})
# show droplist in the ui #
output$selector <- renderUI({
droplist <- dbGetQuery(pool, "SELECT name FROM Table")
selectInput("paria", "Delete row", droplist$name)
})
# Delete Row # Function A #
output$val1 <- renderText({
delete <- sprintf(
"DELETE FROM %s WHERE %s = '%s'",
"Table",
"name",
input$paria
)
if (input$action1 == 0)
return()
isolate({
dbGetQuery(pool, delete)
print("Deletion Successful")
})
})
# Insert row # Function B #
output$val1 <- renderText({
query <- sprintf(
"INSERT INTO %s (%s, %s) VALUES ('%s', '%s')",
"Table",
"name",
"lastname",
input$name,
input$lastname
)
if (input$action2 == 0)
return()
isolate({
dbGetQuery(pool, query)
print("Update Successful")
})
})
})
The ui is the following:
shinyUI(pageWithSidebar(
headerPanel("Little Program"),
sidebarPanel(
conditionalPanel(condition="input.conditionedPanels==1",
textInput("name", "Name"),
textInput("lastname", "Lastname"),
actionButton("action", "Save new person"),
br(),br(),
uiOutput("selector"),
actionButton("action2", "Delete existing person")
),
conditionalPanel(condition="input.conditionedPanels==2",
helpText("Content Panel 2")
)
),
mainPanel(
tabsetPanel(
tabPanel("Table", value=1, verbatimTextOutput("val1"), dataTableOutput('view')),
tabPanel("Panel 2", value=2)
, id = "conditionedPanels"
)
)
))
Thank you very much for the help.
output is to display.
Here the insert and delete are more like side effects. Then you should use observeEvent
Herebelow I created 2 functions, insert and delete and call them from observeEvent based on two actionButton.
server.R
shinyServer(
function(input, output) {
pool <- dbPool(
drv = dbDriver("PostgreSQL", max.con = 100),
dbname = "postgres",
host = "localhost",
user = "postgres",
password = "123",
idleTimeout = 36000
)
# Show table in the ui #
output$view <- renderDataTable({
dbTable<-dbGetQuery(pool, "SELECT * FROM Table")
dbTable <- select(dbTable, name, lastname)
names(dbTable)<-c('Name', 'Lastname')
dbTable
})
# show droplist in the ui #
output$selector <- renderUI({
droplist <- dbGetQuery(pool, "SELECT name FROM Table")
selectInput("paria", "Delete row", droplist$name)
})
# Delete function
delete <- function(paria) {
queryDelete <- sprintf(
"DELETE FROM %s WHERE %s = '%s'",
"Table",
"name",
paria
)
dbGetQuery(pool, queryDelete)
print("Deletion Successful")
}
# Insert function
insert <- function(name, lastname) {
queryInsert <- sprintf(
"INSERT INTO %s (%s, %s) VALUES ('%s', '%s')",
"Table",
"name",
"lastname",
name,
lastname
)
dbGetQuery(pool, queryInsert)
print("Insert Successful")
}
# when delete
observeEvent(input$delete, {
delete(paria = input$paria)
})
# When insert
observeEvent(input$insert, {
insert(name = input$name, lastname = input$lastname)
})
})
ui.R
shinyUI(pageWithSidebar(
headerPanel("Little Program"),
sidebarPanel(
conditionalPanel(condition="input.conditionedPanels==1",
textInput("name", "Name"),
textInput("lastname", "Lastname"),
actionButton("action", "Save new person"),
actionButton("delete", "DELETE !"),
actionButton("insert", "INSERT !")
br(),br(),
uiOutput("selector")
),
conditionalPanel(condition="input.conditionedPanels==2",
helpText("Content Panel 2")
)
),
mainPanel(
tabsetPanel(
tabPanel("Table"
,dataTableOutput('view')
),
tabPanel("Panel 2", value=2)
, id = "conditionedPanels"
)
)
))