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 can't 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
In retrospect, we realize that the way syncUnderscoreCodings is written
is backwards. 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 weren't 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 don't use
underscores in the checkbox codings
If your scripts were written under REDCap 5.5.21 or higher, you will have no backward compatibility problems related to this issue.
Benjamin Nutter
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.