Using shiny modules a large shiny application can be broken down into manageable chunks. Modules work well with most aspects of shiny code but care needs to be taken when referencing inputs. This is especially true when javascript is used within a module. Here's a piece of code which uses a callback in a datatable to …

Read More

Method One - Does not work with IE CSS variables are a powerful way to make wholesale changes to the style throughout an entire document. They are set using a custom notation --variable_name and accessed throughout the document using var(--variable_name). With a little javascript these variables can be used in Shiny …

Read More

I had been running a shiny app in which I could halt a long-running process. The process would update the shiny app and constantly looked for an updated shiny variable to inform if a cancel button had been pressed. The code had been adapted from a SO post at …

Read More

The datatable widget is a powerful table-building tool used to display data in shiny apps. It can use many of the datatable plugins and extensions but a small javascript hack is needed for the rowReorder extension which allows rows to be reordered using drag and drop. In the example below, the rowReorder options are …

Read More

Plotly is a great plotting library that I've started to use extensively in part due to the ease in connecting graphs together under R. There is, however, a bug when using error bars in conjunction with a group variable - error bars are not drawn in the correct order. This can be fixed with a hack by adding each group …

Read More

R is a very powerful language but was designed to run single-threaded. There are libraries that will run parallel code but there is no inherent support to run a background process and monitor for completion in the same way that you can in, for example, C++. One way to overcome this is to launch a second instance of R …

Read More

queryBuilder is an htmlwidget wrapper for jQuery queryBuilder, a fantastic jQuery plugin to create queries and filters. The htmlwidget generates a dplyr string that can be used to filter a data frame within a shiny app. In addition I'm playing with some experimental features to expand functionality. The first is a way …

Read More

There are several ways that users can be managed in Shiny apps but they all require access to the config file. User access can be managed within the app itself using a database to hold user information. Two examples are given below: The first utilizes a simple database in which the passwords are not encrypted (not …

Read More