templar 0.5.0

Lightweight, fast, and powerful templating engine
Documentation 
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/*!
Templar filters

Filters are used to process the result of an expression in a template.

# Overview

As an example, the expression `{{ 'hello' | upper }}` uses the "upper" filter to create
the upper case result "HELLO".

# Built in filters

- require: Will throw an error if the result is empty or null
- default(any): Replaces empty, null, or error types with the default value from the args
- length: Returns the length of a string or array
- lower: Lowercase the rendered result
- upper: Uppercase the rendered result
- trim: Trim whitespace off the rendered result
- split(str?): Split a string into an array. Delimited by newline, but an arg can be used to override the delimiter.
- index(int): Retrieve the int index from the array
- join(str?): Join an array with the provided string. Defaults to newline
- string: Forces the result into a string type, usually by rendering it
- key(str): Retrieve the value of the specified key from the dictionary
- escape_html: (alias 'e') Render the result and escape HTML characters
- replace: Replace occurrences of a character in a string
- yaml: (alias yml) Serialize the data into a YAML string. Requires"yaml-extension" feature (default on)
- json(str?): Serialize the data into a JSON string. Set str to 'pretty' to print with indentation. Requires the "json-extension" feature (default on)
- base64(str?): Encode the result as Base64. If the optional string parameter is set to "decode" then it will try to decode instead. Requires "base64-extension" feature (default on)
*/

mod common;

use crate::*;
use std::collections::HashMap;

/// This is the definition used when adding filters to Templar
pub type Filter = dyn Fn(Data, Data) -> Data + Send + Sync;

macro_rules! builtin_filters {
    ($( $( #[ $attr:meta ] )* $name:literal : $method:path ; )*) => {
        pub(crate) fn default_filters() -> HashMap<String, Arc<Filter>> {
            let mut res = HashMap::new();
            $(
                $( #[ $attr ] )*
                res.insert($name.into(), Arc::new($method) as Arc<Filter>);
            )*
            res
        }
    };
}

builtin_filters! {
    "require": common::require;
    "default": common::default;
    "length": common::length;
    "exists": common::exists;
    "lower": common::lower;
    "upper": common::upper;
    "trim": common::trim;
    "split": common::split;
    "index": common::index;
    "join": common::join;
    "string": common::string;
    "key": common::key;
    "escape_html": common::escape_html;
    "e": common::escape_html;
    "replace": common::replace;

    #[cfg(feature = "yaml-extension")]
    "yaml": common::yaml;
    #[cfg(feature = "yaml-extension")]
    "yml": common::yaml;
    #[cfg(feature = "json-extension")]
    "json": common::json;
    #[cfg(feature = "base64-extension")]
    "base64": common::base64;
    #[cfg(feature = "base64-extension")]
    "b64decode": common::b64decode;
    #[cfg(feature = "base64-extension")]
    "b64encode": common::b64encode;
}