Struct handlebars::Helper

pub struct Helper<'rc> { /* private fields */ }

Render-time Helper data when using in a helper definition

Implementations

impl<'reg: 'rc, 'rc> Helper<'rc>

pub fn name(&self) -> &str

Returns helper name

pub fn params(&self) -> &Vec<PathAndJson<'rc>>

Returns all helper params, resolved within the context

pub fn param(&self, idx: usize) -> Option<&PathAndJson<'rc>>

Returns nth helper param, resolved within the context.

Example

To get the first param in {{my_helper abc}} or {{my_helper 2}}, use h.param(0) in helper definition. Variable abc is auto resolved in current context.

use handlebars::*;

fn my_helper(h: &Helper, rc: &mut RenderContext) -> Result<(), RenderError> {
    let v = h.param(0).map(|v| v.value())
        .ok_or(RenderErrorReason::ParamNotFoundForIndex("myhelper", 0));
    // ..
    Ok(())
}

pub fn hash(&self) -> &BTreeMap<&'rc str, PathAndJson<'rc>>

Returns hash, resolved within the context

pub fn hash_get(&self, key: &str) -> Option<&PathAndJson<'rc>>

Return hash value of a given key, resolved within the context

Example

To get the first param in {{my_helper v=abc}} or {{my_helper v=2}}, use h.hash_get("v") in helper definition. Variable abc is auto resolved in current context.

use handlebars::*;

fn my_helper(h: &Helper, rc: &mut RenderContext) -> Result<(), RenderError> {
    let v = h.hash_get("v").map(|v| v.value())
        .ok_or(RenderErrorReason::ParamNotFoundForIndex("my_helper", 0));
    // ..
    Ok(())
}

pub fn template(&self) -> Option<&'rc Template>

Returns the default inner template if the helper is a block helper.

Typically you will render the template via: template.render(registry, render_context)

pub fn inverse(&self) -> Option<&'rc Template>

Returns the template of else branch if any

pub fn is_block(&self) -> bool

Returns if the helper is a block one {{#helper}}{{/helper}} or not {{helper 123}}

pub fn has_block_param(&self) -> bool

Returns if the helper has either a block param or block param pair

pub fn block_param(&self) -> Option<&'rc str>

Returns block param if any

pub fn block_param_pair(&self) -> Option<(&'rc str, &'rc str)>

Return block param pair (for example |key, val|) if any

Trait Implementations

impl<'rc> Clone for Helper<'rc>

fn clone(&self) -> Helper<'rc>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'rc> Debug for Helper<'rc>

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

Formats the value using the given formatter.