# 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: ```hbs

{{#if (or (and @inputs.has_permission @inputs.is_logged_in) (not @inputs.authentication))}}

{{t 'balance'}}: {{number @inputs.balance}}

{{/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. ```hbs {{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: {% tabs %} {% tab title="JS SDK" %} ```javascript const resolvedTemplate = await exh.templatesV2.resolve(templateName, { inputs: { first_name: "John" }, language: "EN", timeZone: "UTC" }); ``` {% endtab %} {% tab title="HTTP API" %} {% code title="POST /templates/v2/{templateName}/resolve " %} ```json { "inputs" : { "first_name": "John" }, "language": "EN", "timeZone": "UTC" } ``` {% endcode %} {% endtab %} {% endtabs %} The `language` is passed to the `t` helper (supported by [i18next](https://www.i18next.com/translation-function/essentials)) 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](https://docs.extrahorizon.com/extrahorizon/services/other/template-service/localizations). 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](https://handlebarsjs.com/guide/expressions.html#subexpressions) can be used to combine multiple helpers: ```handlebars {{#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` ```handlebars {{#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

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}}`

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

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}}}`

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}}}