README.md

In NCEAS/metadig-r: Author MetaDIG checks in R

metadig

The metadig R package provides functions that assist in authoring and running metadata checks in R to be used by the Java metadata quality engine created by the Metadata Improvement and Guidance project (MetaDIG), a National Science Foundation funded project (grant #1443062). When complete and tested, these checks can then be included in quality suites running the Java reference implementation of the quality engine.

The MetaDIG project has defined a methodology for running tests to evaluate the conformance of a metadata document to a set of quality metrics, using an automated metadata quality engine that runs a suite of checks for a single or collection of metadata documents. A data repository that uses this quality engine is located at https://arcticdata.io.

Installation

Install the package using:

# install.packages("remotes")
remotes::install_github("NCEAS/metadig-r")

Usage

check_presence(name)

Checks if the given name is non-NULL and sets an appropriate status and output.

Example: Given name title (/eml/dataset/title): 'My dataset'

check_presence(title)

• Status: SUCCESS
• Output:
  • "Object 'title' was present and was of length 10."

success(message) & failure(message)

Sets the status for a check and, optionally, creates a new output with your message. Once a check's status is set to FAILURE, it cannot be set back to SUCCESS.

Example:

Given name title (/eml/dataset/title)

if (nchar(title) > 100) {
  success("Title was long enough.")
} else {
  failure("Title was too short.")
}

• Status: SUCCESS
• Output:
  • "Title was long enough."

runCheck(checkXML, metadataXML)

Quality checks authored for the Java quality engine can be tested in the R environment using this package. Checks must be written in an XML format designed for the quality engine, which includes the source code of the check.

Examples of quality checks written in R are available in this package within the "inst/extdata" folder. The following example runs a quality check in the R environment, using an example metadata file that is also provided by the package:

library(metadig)
library(xml2)

checkFile <- system.file("extdata/dataset_title_length-check.xml", package = "metadig")
metadataFile <- system.file("extdata/example_EML.xml", package = "metadig")

results <- runCheck(checkFile, metadataFile)

The returned results object provides a status of the check which can include SUCCESS, FAILURE, or SKIP as well as output describing the results of the check.

NCEAS/metadig-r documentation built on June 17, 2022, 5:09 a.m.