Handle Validation Rule Violations with Custom Actions

Takes the results of data validation checks and performs a specified action (either stopping execution or raising a warning) when validation rules are violated. The function provides detailed feedback about which rules failed before taking the specified action.

Usage

action_if_problem(x, message_text, problem_action = c("stop", "warning"))

Arguments

x

A list containing validation results, typically the output from validate_rules(). Must contain a 'summary' element with columns for 'fails' and other validation metrics.

message_text

Character string containing the message to display when violations are found. This message will appear in both the console output and the error/warning.

problem_action

Character string specifying the action to take when violations are found. Must be either "stop" (to halt execution with an error) or "warning" (to continue execution after showing a warning).

Value

Invisibly returns the input list x. Note that if problem_action is "stop" and violations are found, execution will halt before returning.

Details

The function performs these steps:

1. Checks if any validation rules were violated (fails > 0)

2. If violations exist:

   • Prints the provided message_text

   • Displays a summary of only the failed rules

   • Either stops execution or raises a warning based on problem_action

3. If no violations exist, silently returns the input

This function is particularly useful in data processing pipelines where you want to ensure data quality before proceeding with further analysis.

See also

validate_rules for creating the validation results this function processes

Examples

# Example showing how to stop execution on validation failures
try({
  validate_rules(mtcars, "hp_limit" = hp < 200) |>
    action_if_problem(
      message_text = "Validation failed: Some cars exceed HP limit",
      problem_action = "stop"
    )
})
#> [1] "Validation failed: Some cars exceed HP limit"
#>        name items passes fails   nNA  error warning
#>      <char> <int>  <int> <int> <int> <lgcl>  <lgcl>
#> 1: hp_limit    32     25     7     0  FALSE   FALSE
#> Error in action_if_problem(validate_rules(mtcars, hp_limit = hp < 200),  : 
#>   Validation failed: Some cars exceed HP limit

# Example showing how to continue with a warning
validation_results <- validate_rules(mtcars, "hp_limit" = hp < 200) |>
  action_if_problem(
    message_text = "Warning: Some cars exceed HP limit",
    problem_action = "warning"
  )
#> [1] "Warning: Some cars exceed HP limit"
#>        name items passes fails   nNA  error warning
#>      <char> <int>  <int> <int> <int> <lgcl>  <lgcl>
#> 1: hp_limit    32     25     7     0  FALSE   FALSE
#> Warning: Warning: Some cars exceed HP limit