hoaihuongbk/shinyURL

:link: Save and restore the state of Shiny app's widgets by encoding them in an URL query string

Installation

# install.packages("devtools")
devtools::install_github("aoles/shinyURL")

Use

1. Load the package in both server.R and ui.R.

    library("shinyURL")
   

2. In server.R, add inside the server function a call to

    shinyURL.server()
   

   where session is the argument passed to the server function.

3. Add the shinyURL widget to ui.R.

    shinyURL.ui()
   

Restoring of tabset and navbar panels

To save and restore active tabs provide the id argument to the functions tabsetPanel or navbarPage.

Disable encoding of certain inputs

You can suppress certain inputs from being encoded in the query URL by using IDs with a leading dot, e.g. .inputName. These inputs won't be restored.

Limitations

Long URLs

The state of a shiny app gets saved by encoding its input values into an URL. To keep the URL compact and to avoid problems caused by the URL length limit (around 2000 characters) there are some points to keep in mind when developing your app.

1. Avoid long names of inputs but rather use short IDs. For example, instead of

    selectInput("firstDrug", "First drug", choices = drugs)
   

   it's better to have

    selectInput("d1", "First drug", choices = drugs)
   

2. Use named lists for the choices argument in radioButtons and checkboxGroupInput. Then only the names are displayed to the user allowing for shorter values of the control.

These points are especially relevant for apps with lots of controls.

Action buttons

Unfortunately, operations performed using action buttons cannot be reliably recorded and restored.