syncUnderscoreCodings: Synchronize coding of checkbox variables between meta data...

View source: R/syncUnderscoreCodings.R

syncUnderscoreCodingsR Documentation

Synchronize coding of checkbox variables between meta data and records field names.


Due to a bug in the REDCap export module, underscores in checkbox codings are not retained in the suffixes of the field names in the exported records. For example, if variable chk is a checkbox with a coding 'a_b, A and B', the field name in the data export becomes chk___ab. The loss of the underscore causes fieldToVar to fail as it cannot match variable names to the meta data. syncUnderscoreCodings rectifies this problem by searching the suffixes and meta data for underscores. If a discrepancy is found, the underscores are removed from the metadata codings, restoring harmony to the universe. This bug was fixed in REDCap version 5.5.21 and this function does not apply to that and later versions.


syncUnderscoreCodings(records, meta_data, export = TRUE)



The data frame object returned from the API export prior to applying factors, labels, and dates via the fieldToVar function.


Metadata export from exportMetaData


Logical. Specifies if data are being synchronized for import or export


syncUnderscoreCodings performs a series of evaluations. First, it determines if any underscores are found in the checkbox codings. If none are found, the function terminates without changing anything.

If the checkbox codings have underscores, the next evaluation is to determine if the variable names suffixes have matching underscores. If they do, then the function terminates with no changes to the meta data.

For data exports, if the prior two checks find underscores in the meta data and no underscores in the suffixes, the underscores are removed from the meta data and the new meta data returned.

For data imports, the meta data are not altered and the checkbox_field_name_map attribute is used to synchronize field names to the meta data and the expectations of REDCap (for import, REDCap expects the underscore codings to be used.

Backward Compatibility

In retrospect, we realize that the way syncUnderscoreCodings is written is backward. We should have altered the field names in the records data frame. Any scripts that make use of syncUnderscoreCodings and were written prior to version 5.5.21 will fail because the underscores in the codings will now be present where they were not before.

For backward compatibility of redcapAPI, we continue to alter the codings in the meta data. We do not anticipate many problems, as most people do not use underscores in the checkbox codings

If your scripts were written under REDCap 5.5.21 or higher, there will be no backward compatibility problems related to this issue.

redcapAPI documentation built on Sept. 13, 2023, 1:07 a.m.