Enum TemplateError 

pub enum TemplateError {
    Io(Error),
    UndefinedVariable(String),
    Syntax(SyntaxError),
    MissingParams(Vec<String>),
    TypeMismatch {
        name: String,
        expected: String,
        actual: String,
        actual_value: String,
    },
    UnknownFilter(String),
    IncludeNotFound(String),
    DeclarationsMutated {
        details: String,
    },
    ExtraParams(Vec<String>),
    Panic(String),
}

Errors produced by the template engine.

Variants

Io(Error)

I/O error while loading a template file.

UndefinedVariable(String)

A referenced variable was not found in the context.

Syntax(SyntaxError)

Syntax error in the template.

MissingParams(Vec<String>)

Missing required parameters from frontmatter.

TypeMismatch

Type mismatch between declaration and value.

Fields

name: String

Variable name.

expected: String

The type declared in frontmatter.

actual: String

The type found in the context.

actual_value: String

Preview of the actual value for debugging.

UnknownFilter(String)

Unknown filter name.

IncludeNotFound(String)

Include file not found.

DeclarationsMutated

Parameter declarations were mutated at runtime.

Template frontmatter params: declarations are fixed at compile time. If a runtime-reloaded template has different declarations, this error is returned — the template body may be changed freely, but the parameter contract must remain stable.

Fields

details: String

Human-readable description of what changed.

ExtraParams(Vec<String>)

Extra (undeclared) parameters were passed in the context.

The template engine is strict by default: only parameters declared in frontmatter may be passed. Use allow_extra_params on the render call to suppress this check.

Panic(String)

Template rendering halted by an explicit {% panic(...) %} statement.

Implementations

impl TemplateError

pub fn kind(&self) -> ErrorKind

Return the stable, data-independent ErrorKind of this error.

Unlike matching on the enum variants (which also carry payloads), this gives a lightweight, Copy discriminant that language bindings can map onto their own typed-error hierarchies without parsing the display message.

Trait Implementations

impl Debug for TemplateError

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

Formats the value using the given formatter.

impl Display for TemplateError

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

Formats the value using the given formatter.

impl Error for TemplateError

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 From<Error> for TemplateError

fn from(source: Error) -> TemplateError

Converts to this type from the input type.