rLocker

Learning Locker xAPI support for Shiny Applications.

About xAPI

xAPI [Experience API] is 100% free, open source, lightweight, and adaptable. It can be used to augment almost any performance assessment situation. It is being used in an expanding array of learning systems, from LMSs and simulator systems to museums and emergency medical services. – adlnet.gov

See also: What is the Experience API?

Assumptions

1. This package assumes that you have a Learning Locker instance set up and that it’s reachable by your application.
2. Your application is running in an environment that supports Cross-Origin Resource Sharing (CORS); otherwise API requests will be blocked. Requests made from localhost / 127.0.0.1 / RStudio’s runApp() are often blocked for this reason.
3. You are given consent by the application user(s) to collect activity data on them. Note: unless specified, user identifiers are anonymized by default.

Installation

You can install the released version of rLocker from GitHub with:

devtools::install_github("EducationShinyAppTeam/rLocker")

Examples

See the examples folder for demo code or visit psu-eberly.shinyapps.io/rLocker to see it in action.

Storage Mechanism

Below are two approaches to creating and storing a simple xAPI statement in Learning Locker.

Method 1: R handler

app.R

library(shiny)
library(rLocker)

shinyApp(
  server = function(input, output, session) {

    # Initialize Learning Locker connection -- substitute with your own locker credentials
    rLocker::connect(session, list(
      base_url = "https://learning-locker.example.com/",
      endpoint = "/data/xAPI/",
      auth = "Basic YWNjb3VudEBlbWFpbC5jb206c3VwZXJzZWNyZXRwYXNzd29yZA"
    ))

    # Register input event for interactive elements
    observeEvent(input$button, {
      statement <- rLocker::createStatement()
      rLocker::store(statement)
    })
  }
)

Method 2: JavaScript handler

app.R

library(shiny)
library(rLocker)

shinyApp(
  ui = fluidPage(
    # Attach js logic
    tags$script(src = "js/app.js"),
    
    # Application title
    titlePanel("rLocker demo"),
    fluidRow(
      actionButton("button", "Press me!")
    )
  ),
  server = function(input, output, session) {

    # Initialize Learning Locker connection -- substitute with your own locker credentials
    config <- jsonlite::toJSON(
      list(
        base_url = "https://learning-locker.example.com/",
        endpoint = "/data/xAPI/",
        auth = "Basic YWNjb3VudEBlbWFpbC5jb206c3VwZXJzZWNyZXRwYXNzd29yZA"
      ),
      pretty = TRUE,
      auto_unbox = TRUE,
      force = TRUE
    )
    
    session$sendCustomMessage(type = 'rlocker-setup', config)
    
    # Register input events for interactive elements
    observeEvent(input$button, {
      session$sendCustomMessage(type = 'rlocker-store', rLocker::createStatement())
    })
  }
)

www/js/app.js

Shiny.addCustomMessageHandler('rlocker-setup', function(config) {
  /* connection logic */
});

Shiny.addCustomMessageHandler('rlocker-store', function(values) {
  /* storage logic */
});

See adlnet/xAPIWrapper for JavaScript implementations.

Data Retreival

Stored statements can be retreived from Learning Locker by using the retrieve method.

Note: This requires a connection to be established by the R-handler to work; JS implementations can interface with the API through XMLHttpRequest instead.

app.R

response <- rLocker::retrieve(
  interface = "connection",
  model = "statement",
  query = "first=1",
  asJSON = TRUE
)

print(response)

Response data can be returned as a JSON formatted string or as an R object (default). Below is sample output from the request above.

OUTPUT JSON

{
  "edges": [
    {
      "cursor": "eyJfaWQiOiI1YzQ2MmRiYjI0ZjVmMDRhOTI0MjZlMWMifQ==",
      "node": {
        "person": {},
        "completedQueues": [],
        "processingQueues": [],
        "deadForwardingQueue": [],
        "pendingForwardingQueue": [],
        "completedForwardingQueue": [],
        "_id": "5c462dbb24f5f04a92426e1c",
        "hasGeneratedId": false,
        "organisation": "5c4383e369b9834b4e086caa",
        "lrs_id": "5c46260e85ce554a24b7579f",
        "client": "5c46260e85ce554a24b757a0",
        "active": true,
        "voided": false,
        "timestamp": "2019-01-21T20:38:19.131Z",
        "stored": "2019-01-21T20:38:19.131Z",
        "hash": "0905ec8aa05e67d247d7c888baf80b1f65c439c9",
        "agents": [
          "886b382eb3a9570aeb3da9b34028a76ed761f1b9"
        ],
        "relatedAgents": [
          "886b382eb3a9570aeb3da9b34028a76ed761f1b9",
          "mailto:[email protected]"
        ],
        "registrations": [],
        "verbs": [
          "http://adlnet.gov/expapi/verbs/launched"
        ],
        "activities": [
          "http://127.0.0.1:4358/"
        ],
        "relatedActivities": [
          "http://127.0.0.1:4358/"
        ],
        "statement": {
          "actor": {
            "objectType": "Agent",
            "name": "b5958c7b-22ba-404f-af7d-e5c3ccc6ddea",
            "mbox_sha1sum": "886b382eb3a9570aeb3da9b34028a76ed761f1b9"
          },
          "verb": {
            "id": "http://adlnet.gov/expapi/verbs/launched",
            "display": {
              "en-US": "launched"
            }
          },
          "object": {
            "objectType": "Activity",
            "id": "http://127.0.0.1:4358/",
            "definition": {
              "name": {
                "en-US": "rLocker demo"
              }
            }
          },
          "id": "baa14dff-fbb2-4722-94a2-ecb268193436",
          "timestamp": "2019-01-21T20:38:19.131Z",
          "stored": "2019-01-21T20:38:19.131Z",
          "authority": {
            "objectType": "Agent",
            "name": "New Client",
            "mbox": "mailto:[email protected]"
          },
          "version": "1.0.0"
        },
        "failedForwardingLog": []
      }
    }
  ],
  "pageInfo": {
    "hasNextPage": true,
    "hasPreviousPage": false,
    "startCursor": "eyJfaWQiOiI1YzQ2MmRiYjI0ZjVmMDRhOTI0MjZlMWMifQ==",
    "endCursor": "eyJfaWQiOiI1YzQ2MmRiYjI0ZjVmMDRhOTI0MjZlMWMifQ=="
  }
}

See HTTP Queries for more information on how to make calls to the records database.

Configuration

option	default
base_url	http://localhost:8000/xapi/
endpoint	/data/xAPI/
auth	Basic YWNjb3VudEBlbWFpbC5jb206c3VwZXJzZWNyZXRwYXNzd29yZA
username	null
password	null

Note: base_url should be the hosting location for your locker’s API without any endpoint or home.