Helpers in Templates

Our Template Service is built on top of Handlebars and extends its core functionality with a set of additional helpers.

On this page, you’ll find an overview of the available helpers, including their purpose, expected parameters, and usage examples.

For more information about standard Handlebars syntax and built-in helpers, refer to the official documentation: https://handlebarsjs.com/guide/

<h2>{{t 'greeting' name=@inputs.first_name}}</h2>

{{#if (or (and @inputs.has_permission @inputs.is_logged_in) (not @inputs.authentication))}}
  <p>{{t 'dashboard_access_granted'}}</p>
  <p>{{t 'balance'}}: {{number @inputs.balance}}</p>
{{else}}
  <p>{{t 'dashboard_access_denied'}}</p>
{{/if}}

Translation and internationalization

The t, number, currency, datetime, and relativetime helpers are language and time zone aware, using the template rendering context to determine formatting behavior.

{{t 'greeting' name=@inputs.first_name}}
{{t 'balance'}}: {{number @inputs.balance}}

Language and time zone resolution

All formatting helpers use the language property from the resolve input:

JS SDK

const resolvedTemplate = await exh.templatesV2.resolve(templateName, {
  inputs: {
    first_name: "John"
  },
  language: "EN",
  timeZone: "UTC"
});

HTTP API

The language is passed to the t helper (supported by i18next) to determine to which language the supplied localization key needs to be translated. A deeper explanation on how to localize strings in templates can be found in on the Localizations in Templates page.

This language is also passed internally to the corresponding Intl.* formatter and determines:

• Number formatting (decimal separators, grouping) via number

• Currency formatting (symbol placement, spacing) via currency

• Date and time formatting (month names, ordering, 12/24h clock) via datetime

• Relative time phrasing (e.g., “1 day ago”) via relativetime

If no language is provided, "EN" is used.

The datetime helper additionally respects the timeZone property from the resolve input. If provided, it is passed to Intl.DateTimeFormat. If omitted, the time zone "UTC" is used.

Combining helpers

Subexpressions can be used to combine multiple helpers:

{{#le (sum @inputs.price @inputs.tax) @inputs.cash}}
    Buy
{{else}}
    Don't buy
}}

In this example, sum is used as a subexpression and is evaluated first inside round brackets (...), after which its result is passed as an argument to le.

This can also be used to construct if cases with combined and ,or and not

{{#if (or (and @inputs.has_permission @inputs.is_logged_in) (not @inputs.authentication))}}
    Show me the page
{{else}}
    Please authenticate first
{{/if}}

API reference

Translation and internationalization helpers

Name	Behaviour	Example
t	Translates a key using the current language (supports interpolation) See more in Localizations in Templates page.	Input: {{t 'greeting'}} Output: Dear,
number	Formats a number using locale-aware formatting (Intl.NumberFormat)	Input: {{number 1234.56 style='decimal' maximumSignificantDigits=3 }} Output: 1.230
currency	Formats a number as localized currency (Intl.NumberFormat)	Input: {{currency 1234,56 currency="EUR"}} Output: 1 234,56 €
datetime	Formats a date/time using locale and timezone (Intl.DateTimeFormat)	Input: {{datetime 0 weekday="short" year="numeric" month="long" day="2-digit" hour="2-digit"}} Output: Thu, January 01, 1970 at 12 AM
relativetime	Formats relative time (e.g. “1 day ago”) (Intl.RelativeTimeFormat)	{{relativetime -1 range='days' style='long'}} Output: 1 day ago

Logical helpers

Name	Behaviour	Example
and	Logical AND (arg1 && arg2)	{{#and @inputs.isActive @inputs.isVerified}} Valid {{else}} Invalid {{/and}}
or	Logical OR (arg1 || arg2)	{{#or @inputs.isAdmin @inputs.isEditor}} Has access {{else}} No access {{/or}}
not	Logical NOT (!arg1)	{{#not @inputs.isDeleted}} Visible {{else}} Deleted {{/not}}

Comparison helpers

Name	Behaviour	Example
eq	Checks equality (arg1 == arg2)	{{#eq @inputs.status "active"}} Active {{else}} Inactive {{/eq}}
ne	Checks inequality (arg1 != arg2)	{{#ne @inputs.status "active"}} Inactive {{else}} Active {{/eq}}
gt	Greater than (arg1 > arg2)	{{#gt @inputs.score 50}} Passed {{else}} Failed {{/gt}}
ge	Greater than or equal (arg1 >= arg2)	{{#ge @inputs.age 18}} Adult {{else}} Minor {{/ge}}
lt	Less than (arg1 < arg2)	{{#lt @inputs.stock 1}} Out of stock {{else}} Available {{/lt}}
le	Less than or equal (arg1 <= arg2)	{{#le @inputs.attempts 3}} Allowed {{else}} Blocked {{/le}}

Math helpers

Name	Behaviour	Example
sum	Adds all arguments together	Input: {{sum 2 3 4}} Output: 9
subtract	Subtracts each next argument from the first	Input: {{subtract 10 3 2}} Output: 5
multiply	Multiplies all arguments	Input: {{multiply 2 3 4}} Output: 24
divide	Divides the first argument by the rest sequentially	Input: {{divide 20 2 2}} Output: 5
mod	Returns remainder of a division (arg1 % arg2)	Input: {{mod 10 3}} Output: 1
floor	Rounds a number down	Input: {{floor 4.8}} Output: 4
ceil	Rounds a number up	Input: {{ceil 4.2}} Output: 5
round	Rounds to the nearest integer	Input: {{round 4.5}} Output: 5

Array helpers

Name	Behaviour	Example
length	Returns the length of an array	{{length items}}
includes	Checks whether an array contains a value	{{#includes @inputs.tags "tag_1"}} Has the tag {{else}} Doesn't have the tag {{/includes}}
join	Joins array elements using a separator	{{join @inputs.tags sep=', '}}

String helpers

Name	Behaviour	Example
includes	Checks whether a string contains a substring	{{#includes title "Admin"}} Contains Admin {{else}} Does not contain Admin {{/includes}}
length	Returns the length of a string	{{length @inputs.title}}
join	Joins multiple arguments using a separator (default ", ")	{{join "apple" "banana" "orange" sep=' - ' }}

Object helpers

Name	Behaviour	Example
toJsonString	Serializes data into a JSON string. Because JSON may contain special characters, the way you render the output depends on the context. If used in plain text or in HTML within a <script> tag, use triple braces ({{{ }}}) to prevent HTML escaping. Any mention of </script will also be replaced by <\/script to prevent the JSON from accidentally breaking out of the <script> tag. Double braces ({{ }}) can be used if you want to render the JSON as text in HTML.	{{{toJsonString @inputs}}}