bomboni_template

Utilities for working with Handlebars templates.

This crate provides a collection of custom Handlebars helpers for template rendering. It includes helpers for mathematical operations, string transformations, value manipulation, conditional logic, and dynamic template rendering.

Examples

Math Operations

use handlebars::Handlebars;
use serde_json::Value;
use bomboni_template::helpers::register_helpers;

let mut hbs = Handlebars::new();
register_helpers(&mut hbs);

// Basic arithmetic
assert_eq!(hbs.render_template("{{add 1 2}}", &Value::Null).unwrap(), "3.0");

// Advanced operations
assert_eq!(hbs.render_template("{{sqrt 2}}", &Value::Null).unwrap(), "1.4142135623730951");
assert_eq!(hbs.render_template("{{pow 2 8}}", &Value::Null).unwrap(), "256.0");
assert_eq!(hbs.render_template("{{clamp 5 1 3}}", &Value::Null).unwrap(), "3.0");

String Case Conversion

use handlebars::Handlebars;
use serde_json::Value;
use bomboni_template::helpers::register_helpers;

let mut hbs = Handlebars::new();
register_helpers(&mut hbs);

// Case conversion
assert_eq!(
    hbs.render_template(r#"{{upperCase "hello world"}}"#, &Value::Null).unwrap(),
    "HELLO WORLD"
);

assert_eq!(
    hbs.render_template(r#"{{pascalCase "hello world"}}"#, &Value::Null).unwrap(),
    "HelloWorld"
);

assert_eq!(
    hbs.render_template(r#"{{snakeCase "hello world"}}"#, &Value::Null).unwrap(),
    "hello_world"
);

assert_eq!(
    hbs.render_template(r#"{{screamingSnakeCase "hello world"}}"#, &Value::Null).unwrap(),
    "HELLO_WORLD"
);

// String formatting
assert_eq!(
    hbs.render_template(r"{{toIntegerString 3.14}}", &Value::Null).unwrap(),
    "3"
);

Value Manipulation

use handlebars::Handlebars;
use serde_json::{Value, json};
use bomboni_template::helpers::register_helpers;

let mut hbs = Handlebars::new();
register_helpers(&mut hbs);

// Object operations
assert_eq!(
    hbs.render_template(r#"{{objectHasKey (object x=42) "x"}}"#, &Value::Null).unwrap(),
    "true"
);

// Array operations
assert_eq!(
    hbs.render_template(r"{{contains (array 1 2 3 4) 2}}", &Value::Null).unwrap(),
    "true"
);

// Check truthiness
assert_eq!(
    hbs.render_template(r"{{none false 0}}", &Value::Null).unwrap(),
    "true"
);

// Group by key
hbs.render_template(
    r#"{{groupBy (array (object x=1 y=2) (object x=2 y=4)) "x"}}"#,
    &Value::Null
).unwrap();

Switch/Case Pattern Matching

use handlebars::Handlebars;
use serde_json::json;
use bomboni_template::helpers::register_helpers;

let mut hbs = Handlebars::new();
register_helpers(&mut hbs);

let template = r#"
{{#switch x}}
    {{#case 42}}life{{/case}}
    {{#case 2 4 8}}power of two{{/case}}
    {{#default}}other{{/default}}
{{/switch}}
"#;

assert_eq!(hbs.render_template(template, &json!({"x": 42})).unwrap().trim(), "life");
assert_eq!(hbs.render_template(template, &json!({"x": 2})).unwrap().trim(), "power of two");
assert_eq!(hbs.render_template(template, &json!({"x": 5})).unwrap().trim(), "other");

Dynamic Template Rendering and Local Variables

use handlebars::Handlebars;
use serde_json::json;
use bomboni_template::helpers::register_helpers;

let mut hbs = Handlebars::new();
register_helpers(&mut hbs);

// Dynamic template rendering
assert_eq!(
    hbs.render_template(r#"{{render "x = {{x}}"}}"#, &json!({"x": 42})).unwrap(),
    "x = 42"
);

// Set local variables
let template = r#"
{{*set name = "John" age = 14000}}
{{@name}} is {{@age}} years old.
"#;
let rendered = hbs.render_template(template, &serde_json::Value::Null).unwrap();
assert_eq!(rendered.trim(), "John is 14000 years old.");

Helpers Reference

Math Helpers

• add: Addition
• subtract: Subtraction
• multiply: Multiplication
• divide: Division
• modulo: Modulo
• negate: Negate value
• absolute: Absolute value
• round: Round to nearest integer
• ceil: Ceiling
• floor: Floor
• sqrt: Square root
• sign: Sign of number
• pow: Power (x^p)
• clamp: Clamp value between min and max

String Helpers

Case Conversion:

• upperCase: UPPER CASE
• lowerCase: lower case
• titleCase: Title Case
• camelCase: camelCase
• pascalCase: PascalCase
• snakeCase: snake_case
• screamingSnakeCase: SCREAMING_SNAKE_CASE
• kebabCase: kebab-case
• trainCase: Train-Case
• And many more (toggleCase, alternatingCase, cobolCase, flatCase, etc.)

Formatting:

• toString: Convert value to string
• toJson: Convert to JSON (with optional pretty parameter)
• concat: Concatenate multiple values
• toIntegerString: Convert to integer string

Value Helpers

• object: Create object from named parameters
• objectHasKey: Check if object has key
• array: Create array from parameters
• groupBy: Group array by key
• contains: Check if haystack contains needle
• none: Check if all values are falsy
• all: Check if all values are truthy
• some: Check if some value is truthy
• filter: Filter array by predicate template
• orElse: Return item if truthy, else fallback
• andThen: Return fallback if item truthy, else item
• eitherOr: Conditional value selection

Switch Helper

• switch: Begin switch statement (takes value parameter)
• case: Match one or more values (supports multiple value parameters)
• default: Fallback when no case matches

Render and Decorators

• render: Dynamically render template string
• set: Set local variables (decorator syntax)