How to invalidate reactive observer using code? - shiny

Given pseduo-like code:
dateRange <- reactive({
input$select_dates #action button
save_selected_date_range()
isolate(input$dateRange)
})
customerId <- reactive({
#check if customer has saved date range if so trigger
saved_info <- saved_preferences(input$customerId)
if(nrow(saved_info) > 0) {
flog.info(saved_info)
updateDateRangeInput(session, "dateRange", start = saved_info$start, end = saved_info$start)
}
input$customerId
})
The scenario:
Inputs:
A selected date range and customer selector. The date range is registered when the action button is pressed.
Desired Action:
We would like the ability to load saved date ranges if available when a customer is picked.
Question:
How do I trigger the input$select_dates as if the action button was pushed? Something like invalidateLater without the timer would be nice. Or if there is a manual way to mark or flag the input$select_dates as invalidated.

Define a reactive value
rv <- reactiveValues( v = 0)
put it inside your reactive expression
dateRange <- reactive({
rv$v
input$select_dates #action button
save_selected_date_range()
isolate(input$dateRange)
})
just change the value of rv$v (like rv$v <- rv$v + 1) in any part of your code and the dateRage expression will be invalidated.

Related

isolate input in a module shiny when using insert ui

I'd like to create several ui which use an input parameter. The problem is that the new UI created are still reacting to the input even when I put an isolate()
The right behaviour would give a custom UI created and isolated from the new inputs coming from the selectInput()
For instance I'd like a first UI with the year 2019 selected and second UI with the year 2020.
Here we can see that adding 2020 will change in each UI which is wrong.
library(shiny)
customplotUI <- function(id){
ns <- NS(id)
fluidPage(
sidebarPanel(id=ns("sidebarpanel"),
actionButton(ns("add"),label = "Add"),
selectInput(inputId=ns("years"),label="Year :", choices = c(2019,2020),selected = 2019, multiple = TRUE)),
mainPanel(div(id=ns("placeholder"))
)
)
}
customplot <- function(input,output,session){
ns <- session$ns
output$res <- renderPrint({
data <- data.frame(year=c(2019,2020),value=c("mtcars2019","mtcars2020"))
data[data$year %in% input$years,]})
ctn <- reactiveVal(0)
Id <- reactive({
function(id){
paste0(id, ctn())
}
})
IdNS <- reactive({
function(id){
ns(paste0(id, ctn()))
}
})
observeEvent(input$add, {
ctn(ctn() + 1)
print(Id()('div'))
insertUI(
selector = paste0('#', ns('placeholder')),
ui = div(
id = Id()('div'),
verbatimTextOutput(IdNS()('chart'))
)
)
id <- Id()('chart')
output[[id]] <- renderPrint({
data <- data.frame(year=c(2019,2020),value=c("mtcars2019","mtcars2020"))
#data[data$year %in% isolate(input$years),]
data[data$year %in% input$years,]
})
})
}
ui <- fluidPage(
customplotUI(id="customplot")
)
server <- function(input, output, session){
callModule(customplot,id="customplot",session=session)
}
shinyApp(ui, server)
Perhaps I'm misunderstanding what you're trying to accomplish, but when I run the code, using the commented line with isolate seems to work as intended.
I'm guessing that in creating the minimal reprex (thank you for doing this btw!), you might have gone a little too minimal and removed another reactive that updates data. If you are trying to have the individual UI elements update based on some other input but keep the same filtering scheme, you need to capture the current value of input$years outside of the renderPrint statement.
Here you can see the subset of rows is unchanged, but the last column updates based on input box:
...
id <- Id()('chart')
targetYears <- input$years
output[[id]] <- renderPrint({
data <- data.frame(year=c(2019,2020),
value=c("mtcars2019","mtcars2020"),
yrInput = paste(input$years, collapse =" "))
data[data$year %in% targetYears, ]
...
isolate only prevents a change in the reactive from triggering an update. If the update is triggered by something else, the current/updated value of the reactive is still used. Through the wonders of R's scoping rules, by capturing the value of input$years in non-reactive variable, targetYears, outside of the renderPrint call and then using that in the renderPrint expression it will always use the the value of the input when output[[id]] was created. The isolate is not needed as you are using observeEvent which will prevent the observer from executing when you change the input.

Updating Shiny UI Element doesn't invalidate its associated input value

I am developing a simple web app using the Interactive Document approach with R_Markdown and Shiny. I have a series of input UI objects that get the user options, each of these modifies the next in a chain, and the final one triggers the output (a chart). So I have
A map, which when clicked defines the
Seasons of data available, when one is selected it gives the
Soil types in the data, when one or more are selected it gives the
Elevation classes in the data, when one is selected we then calculate and draw the
Output chart of the selected data.
So for example there are drop down lists to choose the season and soil(s):
output$season_selector <- renderUI({
cat(file=stderr(), paste("render season selector"), "\n")
selectInput("season", h4("Season?"), my$season_here, selected=my$season_sel)
})
output$soil_selector <- renderUI({
cat(file=stderr(), paste("render soil selector"), "\n")
selectInput("soil", h4("Soils?"), my$soil_here, selected=my$soil_sel,
selectize=FALSE, multiple=TRUE)
})
I observe input$season, and this triggers an update of the "soil" UI element.
observeEvent(input$season, {
...
# reset soil list and default soil selected
my$soil_sel <- my$soil_here
updateSelectInput(session, "soil", choices=my$soil_here, selected=my$soil_sel)
})
However, this does invalidate input$soil (although the UI element options and selection have changed, the user has not made a selection), and so the next step in the cascade doesn't trigger:
observeEvent(input$soil, {
...
# reset elev list and default elev selected
my$soil_sel <- my$soil_here
updateSelectInput(session, "soil", choices=my$soil_here, selected=my$soil_sel)
})
How do I achieve a cascade of reactive UI elements like this? Each reaction needs to trigger either when the UI options and selection changes or when the user makes a different selection. Thanks.
Ok, I think I've fixed it. I needed to use the following pattern, which resets variables further down the chain, and doesn't respond to user inputs unless the value has changed. This avoids duplicate or missing events.
# reset selections
my$soil_default <- my$soil_here
my$soil <- my$soil_default
my$elev <- list(NA)
}) # end reaction to season changing
observeEvent(input$soil, {
req(input$soil, input$soil!="NA")
if (any(my$soil != input$soil)) {
my$soil <- input$soil
my$elev <- list(NA)
}
})
#### react to change of soil ####
observeEvent(my$soil, {
cat(file=stderr(), "\n")
cat(file=stderr(), paste("change of my$soil = "))
cat(file=stderr(), paste(my$soil), "\n")
req(my$soil, my$soil!="NA")

Click on marker to open plot / data table

I'm working on leaflet with shiny. The tools is basic, i have a map with some markers (coming from a table with LONG and LAT).
What I want to do is to open a table or a graph when i click on the marker.
Is there a simple way to do it?
Do you have a really simple example: you have a maker on a map, you click on the marker, and there is a plot or a table or jpeg that s opening?
Here is another example, taken from here and a little bit adapted. When you click on a marker, the table below will change accordingly.
Apart from that, a good resource is this manual here:
https://rstudio.github.io/leaflet/shiny.html
library(leaflet)
library(shiny)
myData <- data.frame(
lat = c(54.406486, 53.406486),
lng = c(-2.925284, -1.925284),
id = c(1,2)
)
ui <- fluidPage(
leafletOutput("map"),
p(),
tableOutput("myTable")
)
server <- shinyServer(function(input, output) {
data <- reactiveValues(clickedMarker=NULL)
# produce the basic leaflet map with single marker
output$map <- renderLeaflet(
leaflet() %>%
addProviderTiles("CartoDB.Positron") %>%
addCircleMarkers(lat = myData$lat, lng = myData$lng, layerId = myData$id)
)
# observe the marker click info and print to console when it is changed.
observeEvent(input$map_marker_click,{
print("observed map_marker_click")
data$clickedMarker <- input$map_marker_click
print(data$clickedMarker)
output$myTable <- renderTable({
return(
subset(myData,id == data$clickedMarker$id)
)
})
})
})
shinyApp(ui, server)
There is a leaflet example file here:
https://github.com/rstudio/shiny-examples/blob/ca20e6b3a6be9d5e75cfb2fcba12dd02384d49e3/063-superzip-example/server.R
# When map is clicked, show a popup with city info
observe({
leafletProxy("map") %>% clearPopups()
event <- input$map_shape_click
if (is.null(event))
return()
isolate({
showZipcodePopup(event$id, event$lat, event$lng)
})
})
Online demo (see what happens when you click on a bubble):
http://shiny.rstudio.com/gallery/superzip-example.html
On the client side, whenever a click on a marker takes place, JavaScript takes this event and communicates with the Shiny server-side which can handle it as input$map_shape_click.

Use Shiny to display bar graph by state

I'm trying to use shiny to create a bar graph for a state that is selected via drop-down box. I'm quite new to R and I've tried a variety of examples to no avail. I have three variables (state, claim #, total $) and for each state there are five values. So something like this:
state <- c("PA", "TX", "NY")
claim_num <- c(1:15)
total <- sample(1000:5000, 15)
df <- (state, claim_num, total)
I want to have something similar to https://beta.rstudioconnect.com/jjallaire/shiny-embedding/#inline-app but I don't know if I can format my data in that was since I would have a lot of NAs.
Do you mean something like this (you can download and run the example)?
library(shiny)
ui <- shinyUI(
fluidPage(
titlePanel("Sample Shiny App"),
sidebarLayout(
sidebarPanel(
uiOutput("stateInput")
),
mainPanel(
plotOutput("statePlot")
)
)
))
server <- shinyServer(function(input, output) {
state <- sample(state.abb, 3, replace = FALSE)
total <- sample(1000:5000, 15)
claimNumber <- 1:15
data <- data.frame(state, total, claimNumber)
output$stateInput <- renderUI({
selectInput(
inputId = "state",
label = "Select a State:",
choices = levels(data$state)
)
})
output$statePlot <- renderPlot({
hist(data$total[data$state == input$state])
})
})
shinyApp(ui = ui, server = server)
What we're doing is taking the list of unique states available in our data frame and passing those to our selectInput that renders as a dropdown in the UI. From here, we can access whatever value the user has selected through the input$state object. More generally, we can access inputs based on whatever we define the inputId to be (in this particular case, we call it state).
Having grabbed the user input, we can then subset the data frame to only return values that correspond to the user-defined state and, in this case, pass those totals values to a plot that we render as output.

Can typeahead be implemented over a dynamically changing dataframe using shinysky?

I am trying to populate a Typeahead box in Shiny, using the ShinySky package in R.
I'm trying to extend the example, where the data used to prepopulate the Typeahead is hardcoded into the textInput.typeahead function:
textInput.typeahead(
id="thti"
,placeholder="type 'name' or '2'"
,local=data.frame(name=c("name1","name2"),info=c("info1","info2")) #<- LOOK!
,valueKey = "name"
,tokens=c(1,2)
,template = HTML("<p class='repo-language'>{{info}}</p> <p class='repo-name'>{{name}}</p> <p class='repo-description'>You need to learn more CSS to customize this further</p>")
)
Having a local dataframe defined in the middle of the function is not what I would like to do, as the example has done here:
,local=data.frame(name=c("name1","name2"),info=c("info1","info2"))
I would like to supply an argument to local that is a reactive object, which is created elsewhere in Shiny.
So far I've been unable to do so.
Here's my strategy for attempting to populate the Lookhead options dynamically using reactivity:
1) Let the user subset a dataframe using a slider.
2) Set up the Lookahead to read in the subsetted dataframe, using something like ,local=subset(DF)
3) Hope that the Lookahead works as it's supposed to.
Seems simple enough? Here's a screenshot, where you can clearly see that the Lookhead doesn't appear underneath the user input of 111. Below is my code. Any help would be greatly appreciated.
library(shiny)
library(shinysky)
options(shiny.trace = F) # change to T for trace
DF <- data.frame(ID=c("111", "222", "333", "444"), info=c("info1", "info2", "info3", "info4"))
runApp(list(ui = pageWithSidebar(
headerPanel("This is a test"),
sidebarPanel(
helpText("I couldn't live without StackOverflow"),
sliderInput("range",
label = "Pick how many rows you want in your dataframe:",
min = 2, max = 4, value = 2, step=1),
helpText("After subsetting the dataframe using the controls above, can we make the Lookahead work?"),
textInput.typeahead(
id="thti"
,placeholder="type ID and info"
,local=subset(DF)
,valueKey = "ID"
,tokens=c(1,2)
,template = HTML("<p class='repo-language'>{{info}}</p> <p class='repo-name'>{{ID}}</p> <p class='repo-description'></p>"))
),
mainPanel(textOutput("text1"),
htmlOutput("text"),
tableOutput('table')
)
),
server = function(input, output, session) {
subsetDF <- reactive({ DF <- DF[1:input$range, ]
DF
})
output$text <- renderUI({
str <- paste("This is how many rows you've chosen for your dataframe:",
input$range)
HTML(paste(str, sep = '<br/>'))
})
output$table <- renderTable(subsetDF())
}
)
)