The reactive tag refers to a variable type and environment used inside Shiny applications based in the R programming language. Reactive elements are dynamic and changing over time usually due to user input to the Shiny application. This tag should be used with questions and errors regarding how to refresh, update, assign, and access user inputs into Shiny. The reactive tag is to be used in conjunction with the r and shiny tag.
Questions tagged [reactive]
2049 questions
0
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1 answer
Log what method in reactive chain thew an exception
I have some methods in my reactive chain that can throw exception. If an exception happens - I don't want to continue executing the chain, and I want to log - what exact action threw the exception.
I wrote a code, that looks something like this:
…
a3dsfcv
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How to get a reactive data.frame in a shiny application
I wonder how I could get my shiny app react to any modification brought to a data.frame. This can be useful in many ways. Something like:
[server part]
rv <- reactiveValues(
df <- data.frame(...)
)
observeEvent(rv$df, {
...
})
Elie Ker Arno
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invalid argument to unary operator - R Shiny
I am trying to plot the common phrases just before a crash versus its frequency. Instead of creating a new slider, I decided to use a slider that is already there on the same page. Since in the chart I only have 17 bars, I want that if the slider…
Deepansh Arora
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1 answer
Make simultaneous WebClient calls and get only the first completed
I'm quite newbie in webflux and I want to do the following thing:
I want to make parallel http requests to the same url with different parameter values and to stop when I get the first non null (and non exceptional) result.
I'm following the example…
Apollo
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1 answer
Shiny eventReactive requiring two invalidations
There are many examples of Shiny apps with eventReactive with multiple inputs that responds when either of the inputs are invalidated. However, I'm trying to create an app with an eventReactive that runs when the app is only started, and only when…
user2602640
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1 answer
Hello shiny app gives me error in reactive expression
Hello i am trying to reproduce an example of shiny apps of RStudio in this link:
https://shiny.rstudio.com/articles/tabsets.html
The shinyapp gives error with the d() reactive expression, and i try to change the expression but gives me error:
The…
Beatriz
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Why is my datatable not rendering in my Shiny App?
I am building a shiny App with a tab that should display a table based on a reactive function.
The UI for that tab looks like this:
tabPanel("Data Download",
selectInput("county_5", "Choose a County", choices = unique(df$name)),
…
linacarrillo
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Why won't my plot render in shiny with a reactive function?
Here is my UI, I am working on plot #2. The 3 choices that appear are columns (numeric) of df.
shinyApp(
#####UI
ui = shinyUI(fluidPage(
# Application title
titlePanel(""),
mainPanel(
tabsetPanel(
# Tab #
…
linacarrillo
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- 6
0
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2 answers
Problems with reactive dataframe and update input in shin R
I am still a beginner with the use of shiny (and the following code will clearly demonstrate this fact). I have to generate two barplot in this example of the work I am doing. Both plots are derived from a set of data frames, each one associated…
Nicola Caravaggio
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1 answer
shiny - update data based on input using eventReactive
Fairly new to shiny, trying to sort out eventReactive when updating data. In my case, I want the data.frame dat.base to not be recalculated, unless an input (textInput a2) is updated. As opposed to the stoch_data object, which should be recalculated…
user2602640
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1 answer
RxJava: what is the recommended emitter for saving and retrieving data from NoSql DB asynchronously (i.e. reactive approach)
Context: it is my first time working with RxJava.
When coding with RxJava to (1) select documents from NoSql DB and (2) insert to NoSql (ex. MongoDb), what is the the recommended emmitter taking in account a Reactive Stack?
For instance, should I…
Jim C
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1 answer
display percentile in reactive table (shiny)
I am looking to display tables with low -hight percentile to identify extreme datas.
My final aim is to display in my DB (shiny) each tab in different tabPanel ( (tab1 with percentile <20 ;tab2 with percentile>80) .
I tried a lot of thing but not…
AST_
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Detect when property changed at any element in the list
I googled a lot and still not get an answer. The problem is very silly - I have collection of elements, and need to know when any property changed on any element. Not collection itself changed.
Pseudocode:
public class Item : ReactiveObject {
…
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0 answers
Reactive GGplot boxplot issue to display by group
EDIT : Stefan's advice integrated
My initial problem was that when I made a box plot (ggplot) I got the values by groups (for example, by months) but when I made the same thing in reactive mode, I only got a global boxplot.
The solution was to…
AST_
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ElasticSearch throwing 503 error while storing logs
Reading log message from kafka and storing into elastic search from my reactive spring application, getting the following 2 errors:
1. reactor.retry.RetryExhaustedException:
org.springframework.web.client.HttpServerErrorException:
503 POST request…
Abdul Basith
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