Using Shiny App Builder

Using the Shiny App Builder

The shiny app builder provides a way to combine different shiny modules into a single app. For example, if you have a characterization study, an cohort method study and a prediction study that are related as they all use the same cohorts, then you may want to view the results in a single shiny app. This can be done by using ShinyAppBuilder to combine the characterization, cohort method and prediction shiny modules in OhdsiShinyModule. The main source of shiny modules is the OhdsiShinyModule R package, however, it is possible to add modules from other R packages.

In this vignette we provide examples on how to use the ShinyAppBuilder to create flexible shiny apps for exploring OHDSI results.

The ShinyAppBuilder requires that all results be explored by the shiny app are saved into a single database (i.e., all results for the different shiny modules in an app are saved into the same database), as a single database connection is shared across shiny modules.

Example 1

To create a shiny app that contains four shiny modules:

About (an introduction to the shiny app)
Cohort Generation (details about generated cohorts)
Cohort Method (details about causal inference studies via the cohort method)
Prediction (details about patient level prediction models)

All of these are available as shiny modules in OhdsiShinyModules.

Creating module config settings

To create the shiny app via ShinyAppBuilder we first need to create a config specification for all the shiny modules we wish to include into the single shiny app. A config can be created using createModuleConfig.

Inputs	Description
moduleId	a unique id for the shiny app
tabName	The menu text for the module
shinyModulePackage	The R package that contains the shiny module
moduleUiFunction	The name of the module’s UI function
moduleServerFunction	The name of the module’s server function
moduleInfoBoxFile	The function in the shinyModulePackage package that contains the helper information
moduleIcon	An icon to use in the menu for this module

Note: it is possible to add shiny modules from any R package by setting shinyModulePackage to the R package with the UI and server functions and then specifying the UI function as moduleUiFunction and server function as moduleServerFunction. However, the server function must take as input id (the module id as standard for shiny server modules) and resultDatabaseSettings (a list containing the database result details required when extracting the results from the database).

Creating the about module config

For the about module we will use the about shiny modules in OhdsiShinyModule. The UI is named aboutViewer, the server is named aboutServer and the about helper function is called aboutHelperFile(). As the about module provides information about the shiny app, the ‘info’ icon seems appropriate. The inputs into createModuleConfig for an about module are:

aboutModule <- createModuleConfig(
      moduleId = 'about',
      tabName = "About",
      shinyModulePackage = "OhdsiShinyModule",
      moduleUiFunction = 'aboutViewer',
      moduleServerFunction = 'aboutServer',
      moduleInfoBoxFile =  "aboutHelperFile()",
      moduleIcon = 'info'
    )

For simplicity, the ShinyAppBuilder contains a function called createDefaultAboutConfig with these default about settings into createModuleConfig, this is quicker to use than createModuleConfig if you are using a standard about module. Alternatively, you could just run:

aboutModule <- createDefaultAboutConfig()

Creating the prediction module config

To add a prediction module you can the OhdsiShinyModule functions: aboutPrediction for the module UI, aboutPrediction for the module server and aboutPredictionFile() for the about helper function. A suitable icon is chart-line. For the prediction module, results in the database format created by the PatientLevelPrediction package must be in a database that will be connected to when viewing the shiny app.

predictionModule <- createModuleConfig(
    moduleId = 'prediction',
    tabName = "Prediction",
    shinyModulePackage = 'OhdsiShinyModules',
    moduleUiFunction = "predictionViewer",
    moduleServerFunction = "predictionServer",
    moduleInfoBoxFile =  "predictionHelperFile()",
    moduleIcon = "chart-line"
    )

For simplicity, the ShinyAppBuilder contains a function called createDefaultPredictionConfig with these default prediction settings. Atlernatively, you could just run:

predictionModule <- createDefaultPredictionConfig()

Creating the cohort generation and cohort method using default functions

We have default config creation for cohort method and cohort generation in ShinyAppBuilder:

cohortMethodModule <- createDefaultEstimationConfig()

cohortGeneratorModule <- createDefaultCohortGeneratorConfig()

Combining config settings

Next step is to combine the module config settings into a shiny app config. First we use initializeModuleConfig() to create an empty shiny app config and then we use addModuleConfig() to add each of the module configs we previously created:

library(dplyr)
shinyAppConfig <- initializeModuleConfig() %>%
  addModuleConfig(aboutModule) %>%
  addModuleConfig(cohortGeneratorModule) %>%
  addModuleConfig(cohortMethodModule) %>%
  addModuleConfig(predictionModule)

It is possible to save the shiny app config using saveConfig(shinyAppConfig, 'save location') and load a previously saved shiny app config shinyAppConfig <- loadConfig('save location')

View Shiny App

Create a shiny app for a shiny server

To run the shiny app on a shiny server, specify the connection details to the result database and then just add the following lines of code

# create a connection to the result database
connectionDetails <- DatabaseConnector::createConnectionDetails()
createShinyApp(shinyAppConfig, connectionDetails = connectionDetails)

View shiny app

To just view the shiny app locally, specify the connection details to the result database and then just add the following lines of code

# create a connection to the result database
connectionDetails <- DatabaseConnector::createConnectionDetails()
viewShiny(shinyAppConfig, connectionDetails = connectionDetails)

Example 1 Full Code To View Locally

library(ShinyAppBuilder)
library(dplyr)

aboutModule <- createModuleConfig(
      moduleId = 'about',
      tabName = "About",
      shinyModulePackage = "OhdsiShinyModule",
      moduleUiFunction = 'aboutViewer',
      moduleServerFunction = 'aboutServer',
      moduleInfoBoxFile =  "aboutHelperFile()",
      moduleIcon = 'info'
    )

predictionModule <- createModuleConfig(
    moduleId = 'prediction',
    tabName = "Prediction",
    shinyModulePackage = 'OhdsiShinyModules',
    moduleUiFunction = "predictionViewer",
    moduleServerFunction = "predictionServer",
    moduleInfoBoxFile =  "predictionHelperFile()",
    moduleIcon = "chart-line"
    )

cohortMethodModule <- createDefaultEstimationConfig()

cohortGeneratorModule <- createDefaultCohortGeneratorConfig()


# add the modules into a single shiny config
shinyAppConfig <- initializeModuleConfig() %>%
  addModuleConfig(aboutModule) %>%
  addModuleConfig(cohortGeneratorModule) %>%
  addModuleConfig(cohortMethodModule) %>%
  addModuleConfig(predictionModule)


# add connection details to result database
connectionDetails <- DatabaseConnector::createConnectionDetails()
viewShiny(shinyAppConfig, connectionDetails = connectionDetails)

Jenna Reps, Jamie Gilbert, Josh Ide, Nate Hall

2024-09-25