@jsreport/jsreport-handlebars/async-helpers/helpers/if.js

jsreport handlebars templating engine

const { isPromise, isEmpty } = require('../utils')

module.exports = (handlebars) => {
  handlebars.registerHelper('if', async function (conditional, options) {
    if (arguments.length !== 2) {
      throw new Error('#if requires exactly one argument')
    }
    if (typeof conditional === 'function') {
      conditional = conditional.call(this)
    } else if (isPromise(conditional)) {
      conditional = await conditional
    }

    // Default behavior is to render the positive path if the value is truthy and not empty.
    // The `includeZero` option may be set to treat the conditional as purely not empty based on the
    // behavior of isEmpty. Effectively this determines if 0 is handled by the positive path or negative.
    if ((!options.hash.includeZero && !conditional) || isEmpty(conditional)) {
      return options.inverse(this)
    } else {
      return options.fn(this)
    }
  })

  handlebars.registerHelper('unless', function (conditional, options) {
    if (arguments.length !== 2) {
      throw new Error('#unless requires exactly one argument')
    }
    return handlebars.helpers.if.call(this, conditional, {
      fn: options.inverse,
      inverse: options.fn,
      hash: options.hash
    })
  })
}