Validate visualization specifications in a collection
validate_specs.RdChecks all visualization specs in a collection for common errors before rendering. This includes verifying required parameters are present and that specified column names exist in the data.
Arguments
- collection
A content_collection, viz_collection, page_object, or dashboard_project
- verbose
Logical. If TRUE (default), prints validation results to console. If FALSE, returns silently with results as attributes.
- data
Optional data frame to validate column names against. If NULL, uses data attached to the collection.
Value
Invisibly returns TRUE if all specs are valid, FALSE otherwise. When FALSE, the return value has an "issues" attribute containing details about validation errors.
Details
This function is called automatically by preview() before rendering.
You can also call it manually to check your visualizations before
attempting to render, which provides clearer error messages than
Quarto rendering errors.
Validation checks include:
Required parameters for each visualization type (e.g., x_var for bar charts)
Column existence in the data (when data is available)
Suggestions for typos in column names
Examples
if (FALSE) { # \dontrun{
# Create a collection with an error (missing required params)
# stackedbar requires either (x_var + stack_var) OR x_vars
viz <- create_viz(data = mtcars) %>%
add_viz(type = "stackedbar", x_var = "cyl") # Missing stack_var or x_vars
# Validate before previewing - will show helpful error
validate_specs(viz)
# Use in print with check parameter
print(viz, check = TRUE)
# Programmatic validation (silent)
result <- validate_specs(viz, verbose = FALSE)
if (!result) {
print(attr(result, "issues"))
}
} # }