redcap_metadata_read: Export the metadata of a REDCap project.

Description Usage Arguments Details Value Author(s) References Examples

View source: R/redcap-metadata-read.R

Description

Export the metadata (as a data dictionary) of a REDCap project as a base::data.frame(). Each row in the data dictionary corresponds to one field in the project's dataset.

Usage

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redcap_metadata_read(redcap_uri, token, forms = NULL, forms_collapsed = "",
  fields = NULL, fields_collapsed = "", verbose = TRUE,
  config_options = NULL)

Arguments

redcap_uri

The URI (uniform resource identifier) of the REDCap project. Required.

token

The user-specific string that serves as the password for a project. Required.

forms

An array, where each element corresponds to the REDCap form of the desired fields. Optional.

forms_collapsed

A single string, where the desired forms are separated by commas. Optional.

fields

An array, where each element corresponds to a desired project field. Optional.

fields_collapsed

A single string, where the desired field names are separated by commas. Optional.

verbose

A boolean value indicating if messages should be printed to the R console during the operation. The verbose output might contain sensitive information (e.g. PHI), so turn this off if the output might be visible somewhere public. Optional.

config_options

A list of options to pass to POST method in the httr package. See the details in redcap_read_oneshot(). Optional.

Details

Specifically, it internally uses multiple calls to redcap_read_oneshot() to select and return data. Initially, only primary key is queried through the REDCap API. The long list is then subsetted into partitions, whose sizes are determined by the batch_size parameter. REDCap is then queried for all variables of the subset's subjects. This is repeated for each subset, before returning a unified base::data.frame().

The function allows a delay between calls, which allows the server to attend to other users' requests.

Value

Currently, a list is returned with the following elements,

  • data: An R base::data.frame() of the desired records and columns.

  • success: A boolean value indicating if the operation was apparently successful.

  • status_codes: A collection of http status codes, separated by semicolons. There is one code for each batch attempted.

  • outcome_messages: A collection of human readable strings indicating the operations' semicolons. There is one code for each batch attempted. In an unsuccessful operation, it should contain diagnostic information.

  • forms_collapsed: The desired records IDs, collapsed into a single string, separated by commas.

  • fields_collapsed: The desired field names, collapsed into a single string, separated by commas.

  • elapsed_seconds: The duration of the function.

Author(s)

Will Beasley

References

The official documentation can be found on the 'API Help Page' and 'API Examples' pages on the REDCap wiki (ie, https://community.projectredcap.org/articles/456/api-documentation.html and https://community.projectredcap.org/articles/462/api-examples.html). If you do not have an account for the wiki, please ask your campus REDCap administrator to send you the static material.

Examples

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## Not run: 
library(REDCapR) #Load the package into the current R session.
uri   <- "https://bbmc.ouhsc.edu/redcap/api/"
token <- "9A81268476645C4E5F03428B8AC3AA7B"
redcap_metadata_read(redcap_uri=uri, token=token)

## End(Not run)

REDCapR documentation built on May 19, 2017, 7:01 a.m.

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