Metadata

JSON Metadata

Download the code for this exercise

1. Access the open standard for camera trap data and download Supplementary Material 3, the JSON template. Save the file to your project directory.

2. Install and explore the jsonlite package. There is much more about the relationship between data representation in R and JSON in the accompanying paper.

   install.packages('jsonlite')
   library(jsonlite)
   ?jsonlite
   

3. Read in the JSON template you downloaded.

   ## read in a json schema ####
   template <- fromJSON('oo_99336.json')
   str(template)
   template$CameraTrapMetadataStandard
   

4. From the JSON organization and the open standard paper, the data structure can be recreated. Existing records from a table of images and identifications can be re-arranged and placed into a list to mimic the JSON schema.

   ## combining datasets to match schema definitions ####
   myImages <- list(Project = data.frame(ProjectID = 'thelindyardproject.org',
                       ProjectName = 'Lind backyard Summer 2017', 
                       ProjectObjectives = 'Find out who has been eating my lettuces'),
                 Deployment = data.frame(CameraDeploymentID = c(1:3),
                                         CameraDeploymentBeginDate = c('2017-06-01', 
                                                                       '2017-06-07',
                                                                       '2017-06-10'),
                                         DeploymentLocationID = 'Shed wall'
                                         ),
                 Images = data.frame(imageID = 1:10,
                                      dateTimeCaptured = sample(seq.Date(from = as.Date('2017-06-01'),
                                                                         to = as.Date('2017-07-01'),
                                                                         by = 1), 10, replace = T),
                                      photoType = c('Staff', rep('Animal', 4), 'Unidentifiable', 
                                                    rep('Animal', 4)),
                                      photoTypeIdentifiedBy = 'Eric Lind'),
                 ImageAnimal = data.frame(imageID = c(rep(2, 2), 3, 4, 6:10),
                                          imageCount = 1,
                                          speciesScientificName = c('Vulpes vulpes', rep('Sylvilagus floridanus', 8)))
                       )
   myImages
   

5. Once the structures are named and nested correctly, the export to shareable, findable JSON data is straightforward:

   toJSON(myImages, pretty = T)
   toJSON(template, pretty = T)