Validate a value — validate

This function validates a value. Before validation, it checks the validation expression and optionally performs replacements, where the replacement strings (delimited by the validation replacement delimiters, by default, {{ and }}) are replaced by the first valid corresponding value from the replacementSources (working through those sources consecutively, i.e. only looking in the second one of the first one doesn't contain a valid value for the relevant replacement string, valid being defined as a value that is not NULL or NA and has, after being trimmed of whitespace, a nonzero length).

validate_value(
  VALUE,
  validations,
  replacementSources,
  errorMessages,
  convert_bipiped = TRUE
)

Arguments

VALUE: The value to validate.
validations: The validations, a vector or list that will be consecutively searched for the first valid value (valid being defined as a value that is not NULL or NA and has, after being trimmed of whitespace, a nonzero length). That value has to be either as an R expression, or a character value (i.e. a length 1 character vector) that is a valid R expression, optionally after having performed the specified replacements.
replacementSources: A list of named lists (or 1-row data frames) that will be searched, consecutively, for values to replace the replacement strings with.
errorMessages: The errormessage to return if validation fails, of which the first valid one will be returned (valid being defined as a value that is not NULL or NA and has, after being trimmed of whitespace, a nonzero length).
convert_bipiped: Whether to first run bipiped_value_to_vector() on the replacment values.

Value

The message resulting from the validation (i.e. an error or "").

Details

To change the validation replacement delimiters, use preregr::opts$set(validation_replacementDelimiters = c("{{", "}}"));.

Examples

### Set some validation variables
validationStatement <-
  paste(
    "is.na(VALUE) ||",
    "(VALUE %in% {{validValues}}) ||",
    "(VALUE %in% {{testField}})"
  );
replacementSources <-
  list(
    list(validValues = '"testValue" || "anotherValue"'),
    list(testField = "Yet another testvalue")
  );
errorMessages <-
  "No valid test value passed!";

### Run a passing validation
preregr::validate_value(
  "testValue",
  validations = validationStatement,
  replacementSources = replacementSources,
  errorMessages = errorMessages
);
#> [1] ""


### Run a failing validation
preregr::validate_value(
  "A testvalue that won't pass",
  validations = validationStatement,
  replacementSources = replacementSources,
  errorMessages = errorMessages
);
#> [1] "No valid test value passed!"