/**
* Template engine using LiquidJS
* Supports: {{ field }}, {{ field | filter }}, {% if %}, {% for %}
*/
import { Liquid } from 'liquidjs';
// Singleton Liquid engine instance
const engine = new Liquid({
strictFilters: false,
strictVariables: false,
trimTagLeft: false,
trimTagRight: false,
trimOutputLeft: false,
trimOutputRight: false,
});
/**
* Type for custom helper functions (LiquidJS filter style)
* In LiquidJS: {{ value | filterName: arg1, arg2 }}
* fn receives: (context, value, arg1, arg2)
*/
export type HelperFn = (context: Record<string, unknown>, value: string, ...args: string[]) => unknown;
/**
* Register a custom filter
*/
export function registerFilter(name: string, fn: (value: unknown, ...args: unknown[]) => unknown): void {
engine.registerFilter(name, fn);
}
/**
* Register a custom helper as a LiquidJS filter
* Usage: {{ value | helperName: arg1, arg2 }}
*/
export function registerHelper(name: string, fn: HelperFn): void {
engine.registerFilter(name, (value: unknown, ...args: unknown[]) => {
// Pass empty context for filter usage, value as second param
return fn({}, String(value ?? ''), ...args.map((a) => String(a ?? '')));
});
}
/**
* Render a template string with the given context
*/
export function render(template: string, context: Record<string, unknown>): string {
try {
return engine.parseAndRenderSync(template, context);
} catch (error) {
// On error, return template as-is for debugging
console.error('Template render error:', error);
return template;
}
}
/**
* Compile a template for repeated use (returns render function)
*/
export function compile(template: string): (context: Record<string, unknown>) => string {
const tpl = engine.parse(template);
return (context) => {
try {
return engine.renderSync(tpl, context);
} catch (error) {
console.error('Template render error:', error);
return template;
}
};
}
// Register built-in filters
registerFilter('uppercase', (v) => String(v ?? '').toUpperCase());
registerFilter('lowercase', (v) => String(v ?? '').toLowerCase());
registerFilter('capitalize', (v) => {
const s = String(v ?? '');
return s.charAt(0).toUpperCase() + s.slice(1);
});
registerFilter('trim', (v) => String(v ?? '').trim());
registerFilter('join', (v, separator) => {
if (Array.isArray(v)) {
return v.join(String(separator ?? ', '));
}
return String(v ?? '');
});
