Crowd-sourced systematic reviews and meta-analyses
Shiny’s invalidateLater() function, if you know about it at all, probably doesn’t work the way you think it does. Moreover, the way it actually does work, it turns out, is way cooler than the way it appears to work!
Continue reading “How Shiny’s invalidateLater() actually works”
Several months ago I encountered the emoji that is known as the female sleuth or detective at emojipedia.org.
She comes in a lot of different looks and many of the emoji sets have her in several different skin colors. I’m a real Luddite when it comes to emojis in my personal communications, but I liked the idea of using the Android 7.1 female sleuth as the Open-Meta.org icon.
In my previous post, I demonstrated a JavaScript / jQuery event handler that waits for button clicks and sends the id of the button that was clicked to a single observeEvent() in Shiny. In this post I’m going to improve that code while also extending it to include anchor tags (<a id="xxx">). Anchor tags are typically used to create links and include an href attribute that holds the URL of the linked document.
Continue reading “Adding anchors to our Shiny button observer”
One of the profound limitations of Shiny is the way it supports buttons. Buttons are based on a function called actionButton(). When a button is clicked, Shiny reports the click on input$button_id. Every button has to have a unique id, which means that each button also has to have its own observer to watch for a click. But what if you want to do something like this:
Continue reading “One observer for all buttons in Shiny using JavaScript / jQuery”
Today I decided to try adding the RStudio Server to my Amazon Lightsail instance. There are three steps to this – downloading and installing the software, opening up port 8787, and adding a user with a password who can log in to the server.
Continue reading “Adding RStudio to an Amazon Lightsail Instance”
This week my fellow doctoral students see the first live demonstration (and alpha-test) of the Open-Meta app. Before loading the code onto AWS, I decided to start a new instance and update the installation scripts.
Recording what date and time something happened and reporting it back to users is complicated in multi-user web applications.
Continue reading “R time to our time in multi-user Shiny web applications”
On our server we’re programming in R with a variety of add-on packages, primarily Shiny. Users, on the other hand, are all viewing our site using browsers, which run the programming language JavaScript. This article is about how to use a Shiny command to send a message to the user’s browser, telling it to run a JavaScript function. I’ll also include how to get that JavaScript function to send a message back to Shiny (it will appear as a reactive in the input$ list).
So many choices! In previous blogs I’ve talked about the traditional LAMP stack, in which the “M” stands for the open-source MySQL database engine. I barely understand the details, but somehow Oracle now owns MySQL. There’s still a free open-source version, often referred to as the community edition. Some open-source developers weren’t happy about the Oracle switch, however, and “forked” the MySQL code into a new project called MariaDB.
Connections from your own computer to your instance on Amazon Lightsail are made using SSH keys rather than passwords. Here are some tips for setting up connections between some useful Windows programs and your instance.
Continue reading “How to connect to Amazon Lightsail with PuTTY, FileZilla, WinSCP, and HeidiSQL”