Struct ValidationError 

pub struct ValidationError { /* private fields */ }

A collection of validation errors.

Carries an optional old_input payload for the flash round-trip; set via with_old_input() before calling redirect_back() or redirect_to().

Implementations

impl ValidationError

pub fn new() -> Self

Create a new empty validation error.

pub fn add(&mut self, field: &str, message: impl Into<String>)

Add an error message for a field.

pub fn is_empty(&self) -> bool

Check if there are any errors.

pub fn has(&self, field: &str) -> bool

Check if a specific field has errors.

pub fn get(&self, field: &str) -> Option<&Vec<String>>

Get errors for a specific field.

pub fn first(&self, field: &str) -> Option<&String>

Get the first error for a field.

pub fn all(&self) -> &HashMap<String, Vec<String>>

Get all errors as a map.

pub fn count(&self) -> usize

Get the total number of errors.

pub fn messages(&self) -> Vec<&String>

Get all error messages as a flat list.

pub fn into_messages(self) -> HashMap<String, Vec<String>>

Consume the error and return the inner HashMap of field -> messages. Useful for passing errors to templates.

pub fn to_json(&self) -> Value

Convert to JSON-compatible format for API responses.

pub fn with_old_input(self, data: &Value) -> Self

Attach submitted form values as “old input” for the next GET request.

Chain before redirect_back() or redirect_to(). The caller typically passes the same serde_json::Value used to construct the Validator.

Example

if let Err(e) = validator.validate() {
    return e.with_old_input(&form_data).redirect_back(referer);
}

pub fn redirect_back(self, referer: Option<&str>) -> Response

Flash errors + old input into the session, then redirect to referer.

Falls back to "/" when referer is None or when the Referer header contains a non-same-origin URL (T-92-05 mitigation).

Example

if let Err(e) = validator.validate() {
    let referer = req.header("Referer");
    return e.with_old_input(&form_data).redirect_back(referer);
}

pub fn redirect_to(self, url: impl Into<String>) -> Response

Flash errors + old input into the session, then redirect to an explicit URL.

Use this instead of redirect_back() when the calling controller knows the exact destination (e.g. a tabbed settings form where the Referer may lack the ?tab=... parameter).

Example

if let Err(e) = validator.validate() {
    return e.with_old_input(&form_data).redirect_to("/settings?tab=generale");
}

Trait Implementations

impl Clone for ValidationError

fn clone(&self) -> ValidationError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ValidationError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ValidationError

fn default() -> ValidationError

Returns the “default value” for a type.

impl Display for ValidationError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for ValidationError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl Serialize for ValidationError

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.