selectInput in R shiny - mysql

I want to select from a list read in from a Mysql query. I am getting an error in the code. I must be doing something just completely wrong, but not sure what.
I would like to select from a list of skus read in from a sql query. I get an error in the ui portion.
I am not even sure if this is possible, but to list out all skus would be extremely timely.
I am getting the following errors:
Error in tag("div", list(...)) :
argument "sidebarPanel" is missing, with no default
shinyApp(ui = ui, server = server)
Error in force(ui) : object 'ui' not found
library('RMySQL')
library('plyr')
library('shiny')
library('scales')
library(shinyapps)
library(ggplot2)
con <- dbConnect(MySQL(), user="user", password="password",dbname="DB", host="host");
rank<-dbGetQuery(con,"select sku from DB")
#build a shiny app to select which sku to pick
server <- function(input, output) {
output$distPlot <- renderPlot({
hist(rnorm(input$obs), col = 'darkgray', border = 'white')
})
}
ui <- pageWithSidebar(
## Application title
sidebarPanel(
sliderInput("obs", "Number of observations:", min = 10, max = 500, value = 100),
selectInput(
'e0', '0. An ordinary select input', choices = unique(rank$sku),
selectize = FALSE
),
mainPanel(plotOutput("distPlot"))
)
)
shinyApp(ui = ui, server = server)

You have both a missing bracket near your selectize = FALSE and (as #DavidRobinson has suggested) you need a headerPanel.
CODE FIX
library(shiny)
library(ggplot2)
# con <- dbConnect(MySQL(), user="user", password="password",dbname="DB", host="host");
# rank<-dbGetQuery(con,"select sku from DB")
# for test hard coding the rank as I dont have your data
# test rank
rank$sku <- c(1,2,3)
#build a shiny app to select which sku to pick
server <- function(input, output) {
output$distPlot <- renderPlot({
hist(rnorm(input$obs), col = 'darkgray', border = 'white')
})
}
ui <- pageWithSidebar(
## Application title
# missing headerPanel
headerPanel(title = "Hello"),
# missing bracket after selectize
sidebarPanel(
sliderInput("obs", "Number of observations:", min = 10, max = 500, value = 100),
selectInput(
'e0', '0. An ordinary select input', choices = unique(rank$sku),
selectize = FALSE)
),
mainPanel(plotOutput("distPlot"))
)
shinyApp(ui = ui, server = server)
RESULT
ANOTHER SHINY PAGE UI OPTION
You can can also use a tabbed page structure, replacing ui above with this code (note it does not require headerPanel like above):
# navbar tabbed page example - without headerPanel
ui2 <- navbarPage(title = "Hello Another Style",
tabPanel("Chart Panel",
sidebarLayout(
sidebarPanel(
sliderInput("obs", "Number of observations:",
min = 10, max = 500, value = 100),
selectInput(
'e0', '0. An ordinary select input',
choices = unique(rank$sku),
selectize = FALSE)
),
mainPanel(
plotOutput("distPlot")
)
)
),
tabPanel("Instructions",
mainPanel(
p("Notes here for example...")
)
)
)
SECOND RESULT
And then on second panel...
DEBUGGING ADVICE
These Shiny pages can have lots of brackets, so pace over your code selecting brackets in turn carefully in your editor like RStudio to make sure your brackets match okay.
All the best!

Related

Markdown with RShiny: Input to Global Enviroment

I'd like to ask the user for a number in the Input and use it in several outputs, as well as in independent chunks on a HTML-Markdown. This would mean that I'd like use for example:
ui <- fluidPage(
# "Number of Simulations"
numericInput(inputId = "n",label = "Number of Simulations",
value = 100000,min = 1,max = 200000)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
}
# Run the application
shinyApp(ui = ui, server = server)
And then use input$n outside the ShinyApp. Is there any way? Maybe a way I was trying to figure is this one:
ui <- fluidPage(
# "Number of Simulations"
numericInput(inputId = "n",label = "Number of Simulations",
value = 100000,min = 1,max = 200000)
)
# Define server logic required to draw a histogram
server <- function(input, output) {
reactive({
setwd("C:/Users/alarc/OneDrive/Escritorio/Experimento")
save(input$n,file = "brl.RData")
})
}
# Run the application
shinyApp(ui = ui, server = server)
But it doesn't work. It's like the shiny app couldn't read the save function.

Is there a way to eliminate y scrollers on shiny output in rmarkdown?

I have an interactive doc in rmarkdown using shiny apps.
My YAML:
---
title: "Shiny HTML Doc"
author: "theforestecologist"
date: "Apr 13, 2017"
output: html_document
runtime: shiny
---
I generate a number of shiny apps throughout this document, but they all are too long (i.e., they all require y scrollers to view their entirety.
I know I can add options = list(height = ###,width = ###) within the shinyApp function in my code chunk to control individual rendered apps, but I want my readers to see my shiny code (sans messy option controls).
So my desired approach is to control all of the shiny app outputs at once.
Specifically, is there a way to make it so they each can have variable heights, but each one be fully pictured (i.e., not needing a vertical (y) scroller)?
Example Code:
---
title: "Shiny HTML Doc"
author: "theforestecologist"
date: "Apr 13, 2017"
output: html_document
runtime: shiny
---
I have an interactive shiny doc with app outputs of varying heights.
By default, they all have the same height, which is too small of a value
(and thus creates the need for vertical scrolling bars).
##### **Example 1**
```{r, eval=TRUE,echo=FALSE}
library(shiny)
ui <- fluidPage(
titlePanel("Ex1"),
sidebarLayout(
sidebarPanel(
checkboxGroupInput(inputId = "type", label = "Plant Type", choices = levels(CO2$Type),
selected = levels(CO2$Type))
),
mainPanel(
plotOutput(outputId = "scatter.plot")
)
)
)
server <- function(input, output) {
output$scatter.plot <- renderPlot({
plot(uptake ~ conc, data = CO2, type = "n")
points(uptake ~ conc, data = CO2[CO2$Type %in% c(input$type),])
title(main = "Plant Trends")
})
}
shinyApp(ui = ui, server = server)
```
The output of the next example is longer and therefore needs a larger height assignment to get rid of the scroll bar.
##### **Example 2**
```{r, eval=TRUE,echo=FALSE}
ui <- fluidPage(
titlePanel("Ex1"),
sidebarLayout(
sidebarPanel(
div(style = "padding:0px 0px 450px 0px;",
checkboxGroupInput(inputId = "type", label = "Plant Type", choices = levels(CO2$Type),
selected = levels(CO2$Type))
)
),
mainPanel(
plotOutput(outputId = "scatter.plot")
)
)
)
server <- function(input, output) {
output$scatter.plot <- renderPlot({
plot(uptake ~ conc, data = CO2, type = "n")
points(uptake ~ conc, data = CO2[CO2$Type %in% c(input$type),])
title(main = "Plant Trends")
})
}
shinyApp(ui = ui, server = server)
```

Shiny checkboxGroupInput with Choices Generated From ggplot

I'm trying to create a checkbox for which the choices are plots created through ggplot. In the result, the UI looks like the HTML code itself instead of evaluating the HTML code to show the chart. Any ideas how I can get the checkboxGroupInput to show ggplots?
Sample code below -
runApp(shinyApp(
ui = fluidPage(
headerPanel("Plot check box"),
mainPanel(
uiOutput("plotscheckboxes")
)
),
server = function(input, output, session) {
output$plot1 = renderPlot({
ggplot(mtcars)+geom_point(aes(x=mpg,y=mpg))
})
output$plot2 = renderPlot({
ggplot(mtcars)+geom_point(aes(x=mpg,y=mpg))
})
output$plotscheckboxes = renderUI({
plotlist = list(
plotOutput('plot1'),
plotOutput('plot2')
)
plotlist2 = do.call(tagList, plotlist)
# this just produces a list with 1,2, some sort of underlying value for the checkboxGroup
finaloptionlist = lapply(
seq(length(plotlist2)),
function(x) x
)
# the names of the list are what get used in the options so setting the names accordingly as the HTML code of the ggplot rendering
names(finaloptionlist) = sapply(plotlist2, function(x) paste(x, collapse = "\n"))
checkboxGroupInput("checkGroup", label = h3("Checkbox group"),
choices = finaloptionlist,
selected = 1)
})
}
))

R Shiny: Table object not found in reactive RMySQL query in shiny app

[EDIT]: solution by agstudy worked for me.
I have a shiny app that allows users to toggle between three tables in a MySQL database. Users can select a table which is used by renderTable to generate the object.
I have put if statements in renderTable to respond to the users' selected table.
When I run the app, any table fails to print and cannot be viewed.
server.R
library(shiny)
library(RMySQL)
con <- dbConnect(RMySQL::MySQL(),user="x",password="x",host="dbhost",dbname="db")
shinyServer(function(input, output) {
data <- reactive({
selectInput("input$data", "Choose your Input:", choices = c('data1'='1','data2'='2', 'data3'='3'))
})
output$table <- renderTable({
if(input$data == data1){
query1 <- reactive({ "SELECT *
FROM data1
ORDER BY var1, var2"})
reactive({dbGetQuery(con,query1())})
head(data())
} else if(input$data == data2){
query1 <- reactive({ "SELECT *
FROM data2
ORDER BY var1, var2"})
reactive({dbGetQuery(con,query1())})
head(data())
} else if(input$data == data3){
query1 <- reactive({ "SELECT *
FROM data3
ORDER BY var1, var2"})
reactive({dbGetQuery(con,query1())})
head(data())
} else print("Select a dataset")
})
})
ui.R
library(shiny)
library('RMySQL')
shinyUI(navbarPage("Test",
tabPanel("Test",
sidebarLayout(
sidebarPanel(
selectInput("data", label = "Data set",
choices = c("", "data1", "data2", "data3"))
),
mainPanel(
tableOutput("table")
)
))
))
Your problem here is not in any case related to MySQLserver but there is a no UI logic. Programming in Shiny is not easy if you don't isolate your code parts:
inputs: defined in your ui interface
reactive functions : should change each time you change your input
outputs: be refreshed once the input data is changed by the reactive function.
You miss-understand the reactive.The basic idea is that your don't need to refresh your UI manually, it should be done automatically once the input parameter is changed.
Here I am rewriting completely your code using the Shiny logic:
library(RMySQL)
library(shiny)
## this a public function that will be used
## in the server side to connect to the data base
## and retrieve data
get_data <-
function(query){
on.exit(dbDisconnect(conn)) ## important to close connection
conn <- dbConnect("MySQL",user="xuser",
password="xpws",
host="xhost",
dbname="xdbname")
dbGetQuery(con,query)
}
server <- shinyServer(
function(input, output) {
## the reactive engine that will refresh query
## each time input changed
query <- reactive( sprintf("SELECT *
FROM %s
ORDER BY var1, var2",input$data)
)
## simply displaying reactive inputs
output$table <- renderTable(
if(input$data!="") get_data(query())
)
})
## define ui elements by step
## for easy indenting
ui_panel <-
tabPanel("Test",
sidebarLayout(
sidebarPanel(
selectInput("data", label = "Data set",
choices = c("","data1", "data2", "data3"))
),
mainPanel(
tableOutput("table")
)
)
)
ui <- shinyUI(navbarPage("Test",ui_panel))
runApp(list(ui=ui,server=server))

Shiny isolate - How not to send the hidden conditional input data to the server?

How can I ask Shiny not to send the hidden conditional input data to the server from the Shiny UI?
I have this problem which I don't know how to solve it.
When I select 'One site' and the dropdown select options for the site 2 will be hidden and I don't want any of the site 2 data to be sent to the server.
But Shiny does send the hidden input data to the server when I hit the GO button. How can I not to send it?
Below are my code,
ui.R,
# Site 1 options.
site1 <- selectInput(
inputId = "site1",
label = "Select a first site:",
choices = c('1a', '1b')
)
# Site 2 options.
site2 <- selectInput(
inputId = "site2",
label = "Select a second site:",
choices = c('2a', '2b')
)
shinyUI(
pageWithSidebar(
headerPanel("Shiny App"),
sidebarPanel(
selectInput(
"distribution",
"Please select a type:",
choices = c("Both sites", "One site")
),
# Site select input.
site1,
# Condition when the plot is a line plot.
conditionalPanel(
condition = "input.distribution == 'Both sites'",
site2
),
actionButton("goButton", "Go!")
),
mainPanel(
plotOutput("myPlot")
)
)
)
server.R,
shinyServer(
function(input, output, session) {
output$myPlot = renderPlot({
# Take a dependency on input$goButton
input$goButton
site1 <- isolate(input$site1)
site2 <- isolate(input$site2)
plot(1, 1, col = "white")
text(1, 1, paste(site1, " ", site2))
})
}
)
Here are the visual:
two sites (correct result),
one site (incorrect result),
the expected result,
Any ideas? Is it a bug from Shiny?