An earlier post described a multiwindow shiny app that demonstrated how three shiny apps could be handled by a fourth with data passing between them. This extends the concept, running all apps on RStudio Connect and manages the communication using the {pins} library. Data is passed between the apps using a json file …

Read More

Introduction Here's a simple example of working with a reactive R6 in a shiny app. It is inspired by a post to RStudio Community (https://community.rstudio.com/t/good-way-to-create-a-reactive-aware-r6-class/84890) and uses the code provided by Winston Chang to create an R6 class that is reactive. The example code is …

Read More

Purpose Can we use use RStudio Connect to build an internal contact form on a {distill} website? {distill} is a great R library for building static websites and blogs but has the same limitations of other static websites, namely no server-side programming. This means that implementing a contact form requires using a …

Read More

This is an initial concept of a framework for multiwindow shiny apps. Shiny is a great R package for building an interactive, web-based, graphical UI using R. It does, however, suffer from some limitations. One of these is the fact that a Shiny app runs in a single browser window. To make a more complex interface we …

Read More

The {tidyselect} package powers column selection for {dplyr}, {tidyr} and {recipes} functions but it's also quite straight-forward to include its functonality in other user-built functions. Here's an example which replaces a percentage of a data frame by NA. It works by using the tidyselect::eval_select function to …

Read More

magrittr is the pipe, commonly used in tidyverse packages, that enables simple sequencing of operators. The simple forward pipe replaces f(x, y) with x %>% f(y). Code becomes much more readable when chaining multiple pipes together. It’s very simple to use this in any package. the usethis package provides a command …

Read More

Generally there is no issue in sending a list of parameters (reactive and non-reactive) to a shiny module. Here's an example where a shiny module would be called multiple times, programatically, where the reactive nature of the parameters may be variable (reactive in one instance but not in another). One way to deal …

Read More

Examples of passing a list of reactives, reactiveValues list and reactiveValues to a shiny module. This helps explain reactivity when passing values to a shiny module. In each case we pass a value A which triggers mod A and value B which triggers mod B. The code below and output demonstrates which outputs in the shiny …

Read More

The traveling salesperson problem (TSP) is an NP-complete problem that asks given a list of cities, what's the shortest path that can be taken so that each city is visited once and you end up back where you started. Exact solutions to the problem exist but they become impractical as soon as the number of cities …

Read More

Programatically sending an email under Linux is relatively simple. There are several command line clients such as sendmail and mail which are very easy to use. There are also several R packages to help send emails such as {mailr} and {blastula}. Generally you need access to an SMTP to send messages programatically and …

Read More