Handlebars Helpers

Courier’s custom Handlebars helpers for use in email template overrides and custom brand templates.

The default Handlebars helpers can be found here.

Check out our common use cases documentation on details on how to use these functions. Don’t see a custom handlebars helper you need in the list? Share your use case.

Whitespace Control

Handlebars expressions can leave unwanted blank lines in rendered output, especially when conditionals hide content. Use the tilde (~) character inside expression braces to strip whitespace on that side of the tag.

Syntax	Effect
`{{~expression}}`	Strips whitespace before the tag
`{{expression~}}`	Strips whitespace after the tag
`{{~expression~}}`	Strips whitespace on both sides

This works with all Handlebars tags, including block helpers like #if, #each, else, and closing tags. Example: Blank lines from hidden conditionals Without tilde syntax, a hidden #if block leaves blank lines in the output:

Hello {{var "name"}},

{{#if (var "has_coupon")}}
Your coupon code is: {{var "coupon_code"}}
{{/if}}

Thanks for your order!

When has_coupon is false, this renders as:

Hello Alice,

Thanks for your order!

Adding tildes removes the blank lines:

Hello {{var "name"}},

{{~#if (var "has_coupon")}}
Your coupon code is: {{var "coupon_code"}}
{{~/if~}}

Thanks for your order!

When has_coupon is false, this now renders cleanly:

Hello Alice,
Thanks for your order!

Start by adding ~ to the opening {{~#if and closing {{~/if~}} tags. Adjust placement if the output has too little or too much spacing. The tilde strips all whitespace (including newlines) on its side, so over-applying it can collapse lines together.

Courier Handlebars Helpers

Logic

and

Returns true if all arguments are truthy, false if one argument is falsy, and true if no arguments Parameters

input

Note: Data and profile can have booleans. Example:

{{#if (and (var "boolean") (var "another_boolean"))}}
  <strong>True</strong>
{{else}}
  <strong>False</strong>
{{/if}}
<!-- Output: dependent on variables, 'true' will render if condition returns true -->

<!-- Reference a "profile" variable -->
{{#if (and (var "profile.boolean") (var "profile.another_boolean"))}}
  <strong>True</strong>
{{else}}
  <strong>False</strong>
{{/if}}

condition

Use the if statement to specify a block of code to be executed if a condition is true. Will throw an error if the operator is unsupported.

Require two operands separated by an operator.
Run the appropriate operation on the operands.

Parameters

input

Note: Data and profile can have booleans. Example:

{{#if (condition (var "eligible") "==" "yes")}}
  <strong>Hello!</strong>
{{else}}
  <strong>Bye</strong>
{{/if}}
<!-- Output: dependent on variable -->

<!-- Reference a "profile" variable -->
{{#if (condition (var "profile.name") "==" "rod")}}
  <strong>Hello {{var "profile.name"}}!</strong>
{{else}}
  <strong>Hello there</strong>
{{/if}}

<!-- Reference a boolean -->
{{#if (condition (var "profile.hungry") "==" "true")}}
  <strong>{{var "profile.name"}} is hungry!</strong>
{{else}}
  <strong>{{var "profile.name"}} is not hungry</strong>
{{/if}}

Arithmetic Evaluation Operators: The condition helper supports various comparison operators for arithmetic evaluations:

== - Equal to
!= - Not equal to
> - Greater than
< - Less than
>= - Greater than or equal to
<= - Less than or equal to

Examples:

<!-- Less than -->
{{#if (condition 1 "<" 2)}}
  Display block
{{/if}}

<!-- Greater than -->
{{#if (condition (var "age") ">" 18)}}
  <strong>You are an adult</strong>
{{/if}}

<!-- Greater than or equal to -->
{{#if (condition (var "score") ">=" 100)}}
  <strong>You passed!</strong>
{{/if}}

<!-- Less than or equal to -->
{{#if (condition (var "quantity") "<=" 10)}}
  <strong>Low stock</strong>
{{/if}}

<!-- Not equal to -->
{{#if (condition (var "status") "!=" "inactive")}}
  <strong>Account is active</strong>
{{/if}}

<!-- Equal to -->
{{#if (condition (var "status") "==" "active")}}
  <strong>Welcome back!</strong>
{{/if}}

conditional

Loops through all arguments and ensures all are truthy if using the “and” logical operator.
Loops through all arguments and ensures one is truthy if using the “or” logical operator.
Returns true if the conditions passed, false otherwise (use #unless helper to hide content if condition passes).

Parameters

input

Note: Data and profile can have booleans.

{{conditional
  (filter "data" "customer.name" "EQUALS" "josh")
  (filter "profile" "email" "CONTAINS" "@trycourier.com")
}}
<!-- Output: dependent on variable -->

not

Return false if the argument is truthy. Returns true if argument is false, undefined, null, "", 0, or [] Parameters

input

Example

{{not true}}
<!-- Output: false -->

{{not "string"}}
<!-- Output: false -->

{{not "" }}
<!-- Output: true -->

{{not undefined }}
<!-- Output: true -->

or

Returns true if one argument is truthy, false if all argument are falsy, and false if no arguments. Parameters

input

Note: Data and profile can have booleans.

{{#if (or (var "boolean") (var "another_boolean"))}}
  <strong>True</strong>
{{else}}
  <strong>False</strong>
{{/if}}
<!-- Output: dependent on variables, 'true' will render if condition returns true -->

<!-- Reference a "profile" variable -->
{{#if (or (var "profile.boolean") (var "profile.another_boolean"))}}
  <strong>True</strong>
{{else}}
  <strong>False</strong>
{{/if}}

Data

default

Returns the value if it is not nullish. Parameters

input

Note: Data and profile can have booleans. Example:

{{default undefined (var "customer")}}
<!-- Output: Returns the default value -->

each

Iterates over a list. Inside the block, you can use this to reference the element being iterated over. Parameters

input

Example:

"data": {
    "people": [
      {
        "name": "Rod"
      },
      {
        "name": "TK"
      },
      {
        "name": "Suhas"
      }
    ]
  }

<ul>
  {{#each people}}
    <li>{{this.name}}</li>
  {{/each}}
</ul>
<!-- Output: unordered list -->

NOTEThis is a modified version of this Handlebars helper.

path

Use the variable handler to resolve a JSONPath, and returns the resolved value, similar to var. Returns undefined if the value was not found. Parameters

input

Example:

{{path "profile.doesNotExist"}}
<!-- Output: -->

{{var "profile.doesNotExist"}}
<!-- Output: {profile.doesNotExist} -->

{{#if (path "profile.doesNotExist")}}
abc123
{{/if}}
<!-- Output: -->

{{#if (var "profile.doesNotExist")}}
abc123
{{/if}}
<!-- Output: abc123 -->

set

Set the value of a variable specified by name. The top level names cannot start with brand, data, event, profile, recipient, urls Parameters

name
input

Example:

<!-- Set and re-use a default value-->
{{set "name" (default (path "profile.firstName") "valued_customer" )}}
Dear {{name}},

<!-- Make a variable more readable -->
{{set "city" (path "profile.address.primary.city")}}
{{city}}
<!-- Output: Santa Cruz -->

{{set "month" (datetime-format 1554145200000 "%B")}}
{{month}}
<!-- Output: April-->

var

Uses the variable handler to resolve a JSONPath, and returns the resolved value, similar to path. Returns the variable reference as a string {data.doesNotExist} if the value was not found. Parameters

input

Example:

{{path "profile.doesNotExist"}}
<!-- Output: -->

{{var "profile.doesNotExist"}}
<!-- Output: {profile.doesNotExist} -->

{{#if (path "profile.doesNotExist")}}
abc123
{{/if}}
<!-- Output: -->

{{#if (var "profile.doesNotExist")}}
abc123
{{/if}}
<!-- Output: abc123 -->

with

NOTEThis helper is a modified version of the Handlebars with helper.

Sets the variable scope when rendering the block content. Parameters

input

Example:

{{#with person}}
{{firstname}} {{lastname}}
{{/with}}
<!-- Output: Marty Banks -->

when run in this context

{
  person: {
    firstname: "Marty",
    lastname: "Banks"
  }
}

String

capitalize

Returns the capitalized first character of a given string. Parameters

input

Example

{{capitalize "foo"}}
<!-- Output: Foo -->

<!-- Reference a "data" variable -->
{{capitalize (var "name")}}

<!-- Reference a "profile" variable -->
{{capitalize (var "profile.name")}}

concat

Stringifies all arguments and joins them using the provided separator. Should use null string for the separator by default and should return a null string if no arguments. Parameters

input

Example

{{concat "hello" " " "world"}}
<!-- Output: hello world -->

<!-- Reference a "data" variable -->
{{concat "hello" " " (var "name")}}

<!-- Reference a "profile" variable -->
{{concat "hello" " " (var "profile.name")}}

format

Returns a formatted string given a format and set of arguments. Parameters

input

Example:

{{format "%.2f" (var "number")}}
<!-- If number = 1 | Output: 1.00 -->

datetime-format

Returns a formatted date string, can be set to a user IANA Timezone This helper will throw if an invalid date is provided. Parameters

input

Examples

{{datetime-format 1554145200000 "%a, %B %d %I:%M %p"}}
<!-- Output: Mon, April 01 7:00 pm-->

{{datetime-format 1554145200000 "%a, %B %d %I:%M %p" "America/Los_Angeles"}}
<!-- Output: Mon, April 01 12:00 pm-->

{{datetime-format "2019-04-01T12:00:00.000Z" "%a, %B %d %I:%M %p"}}
<!-- Output: Mon, April 01 12:00 pm-->

{{datetime-format "2019-04-01T12:00:00.000Z" "%a, %B %d %I:%M %p" "America/Los_Angeles"}}
<!-- Output: Mon, April 01 5:00 am-->

INFOSee full list of format options along with an additional option %p to add am, pm

trim-left

Removes whitespace from the beginning of a string, without modifying the original string. Parameters

input

Example:

{{trim-left "  a string"}}
<!-- Output: a string -->

trim-one-char-right

INFOThis helper is for dealing with the following escaping issue.

Returns the string with the last character removed. Parameters

input

Example:

{{a-block (params text=(trim-one-char-right "ends with\ "))}}

trim-right

Removes whitespace from the end of a string, without modifying the original string. Parameters

input

Example:

{{trim-right "a string  "}}
<!-- Output: a string -->

trim

Removes whitespace from the beginning and end of a string, without modifying the original string. Parameters

input

Example:

{{trim "  a string  "}}
<!-- Output: a string -->

truncate

Truncates the string to the number of characters defined in the helper Parameters

input
length
(optional) suffix

Example:

{{ truncate "some very long string" 9 }}
<!-- Output: some very -->

{{ truncate "some very long string" 9 "..." }}
<!-- Output: some very... -->

Math

abs

Return the magnitude of a number. This helper will throw an error if it encounters a value that is not a number. Parameters

input

Example

{{abs -10}}
<!-- Output: 10 -->

<!-- Reference a "data" variable -->
{{abs (var "negative_number")}}

<!-- Reference a "profile" variable -->
{{abs (var "profile.negative_number")}}

add

Returns the the sum of two operands. This helper will throw an error if it encounters an input value that is not a number. Parameters

term
term

Example

{{add 5 3}}
<!-- Output: 8 -->

{{add -1 -3}}
<!-- Output: -4 -->

<!-- Reference a "data" variable -->
{{add (var "term_1") (var "term_2")}}

<!-- Reference a "profile" variable -->
{{add (var "profile.term_1") (var "profile.term_2")}}

ceil

Returns the least integer greater than or equal to the decimal number input. This helper will throw an error if it encounters a value that is not a number. Parameters

input

Example

{{ceil .95}}
<!-- Output: 1 -->

{{ceil 1.01}}
<!-- Output: 2 -->

{{ceil -1.01}}
<!-- Output: -1 -->

<!-- Reference a "data" variable -->
{{ceil (var "some_number")}}

<!-- Reference a "profile" variable -->
{{ceil (var "profile.some_number")}}

divide

Returns the quotient of its operands where the left operand is the dividend and the right operand is the divisor. This helper will throw an error if it encounters an input value that is not a number or if the divisor is 0. Parameters

dividend
divisor

Example

{{divide 12 2}}
<!-- Output: 6 -->

{{divide 3 2}}
<!-- Output: 1.5 -->

<!-- Reference a "data" variable -->
{{divide (var "dividend") (var "divisor")}}

<!-- Reference a "profile" variable -->
{{divide (var "profile.dividend") (var "profile.divisor")}}

floor

Returns the largest integer less than or equal to a given number. This helper will throw an error if it encounters a value that is not a number. Parameters

input

Example

{{floor .95}}
<!-- Output: 0 -->

{{floor 1.01}}
<!-- Output: 1 -->

{{floor -1.01}}
<!-- Output: -2 -->

<!-- Reference a "data" variable -->
{{floor (var "some_number")}}

<!-- Reference a "profile" variable -->
{{floor (var "profile.some_number")}}

inc

Increase value by 1. Parameters

input

Example:

{{inc (var "value")}}
<!-- If value = 1 | Output: 2 -->

mod

Returns the remainder left over when one operand is divided by a second operand. It always takes the sign of the dividend. This helper will throw an error if it encounters an input value that is not a number or if the divisor is 0. Parameters

dividend
divisor

Usage: Example

{{mod 13 5}}
<!-- Output: 3 -->

{{mod -13 5}}
<!-- Output: -3 -->

{{mod 4 2}}
<!-- Output: 0 -->

<!-- Reference a "data" variable -->
{{mod (var "dividend") (var "divisor")}}

<!-- Reference a "profile" variable -->
{{mod (var "profile.dividend") (var "profile.divisor")}}

multiply

Returns the product of two operands. This helper will throw an error if it encounters an input value that is not a number. Parameters

multiplier
multiplicand

Example

{{multiply 12 2}}
<!-- Output: 24 -->

{{multiply -12 2}}
<!-- Output: -24 -->

<!-- Reference a "data" variable -->
{{multiply (var "multiplier") (var "multiplicand")}}

<!-- Reference a "profile" variable -->
{{multiply (var "profile.multiplier") (var "profile.multiplicand")}}

round

Returns the value of a number rounded to the nearest integer. This helper will throw an error if it encounters an input value that is not a number. Parameters

input

Example

{{round 1.5}}
<!-- Output: 2 -->

{{round 1.4}}
<!-- Output: 1 -->

{{round -1.4}}
<!-- Output: -1 -->

{{round -1.5}}
<!-- Output: -2 -->

<!-- Reference a "data" variable -->
{{round (var "some_variable")}}

<!-- Reference a "profile" variable -->
{{round (var "profile.some_variable")}}

subtract (sub)

Returns the difference of two operands. This helper will throw an error if it encounters an input value that is not a number. Parameters

term
term

Example

{{subtract 5 3}}
<!-- Output: 2 -->

{{sub 5 3}}
<!-- Output: 2 -->

{{subtract 3.5 5}}
<!-- Output: -1.5 -->

<!-- Reference a "data" variable -->
{{subtract (var "term_1") (var "term_2")}}

<!-- Reference a "profile" variable -->
{{subtract (var "profile.term_1") (var "profile.term_2")}}

SendWithUs Helpers

SendWithUs helpers are available to help ease migration from your existing Jinja templates to Courier rendered messages.

swu_datetimeformat

Returns a formatted date string. This helper will throw if an invalid date is provided. Parameters

input

Examples

{{swu_datetimeformat 1554145200000 "%a, %B %d"}}
<!-- Output: Mon, April 01 -->

{{swu_datetimeformat "2019-04-01T12:00:00.000Z" "%a, %B %d"}}
<!-- Output: Mon, April 01 -->

INFOSee full list of format options

swu_iso8601_to_time

Returns an ISO-8601 date string as epoch milliseconds. This helper will throw if an invalid date is provided. Parameters

input

Examples

{{swu_iso8601_to_time "2019-04-01T12:00:00.000Z"}}
<!-- Output: 1554145200000 -->

<!-- Reference a "data" variable -->
{{swu_iso8601_to_time (var "some_date_variable")}}

<!-- Reference a "profile" variable -->
{{swu_iso8601_to_time (var "profile.some_date_variable")}}

swu_timestamp_to_time

Returns an Unix epoch timestamp (seconds) as a millisecond epoch time value. This helper will throw if an invalid unix epoch date is not provided. Parameters

input

Examples

{{swu_timestamp_to_time 1554145200}}
<!-- Output: 1554145200000 -->

<!-- Reference a "data" variable -->
{{swu_timestamp_to_time (var "some_timestamp")}}

<!-- Reference a "profile" variable -->
{{swu_timestamp_to_time (var "profile.some_timestamp")}}

translate

Translates a string based on the key, profile locale and .po translations you have uploaded to Courier. Parameters

key
args (multiple, space separated arguments)
domain (only scoped to “default” right now)
locale (fetched automatically from profile right now)

Examples

{{t "Salutation"}}
<!-- Output: "Welcome" -->

<!-- Pass profile attributes as arguments -->
{{t "Salutation" profile.first_name profile.last_name}}
<!-- Output: "Welcome, John Doe" -->

Getting Started

Platform

Tools

Help

​Whitespace Control

​Courier Handlebars Helpers

​Logic

​and

​condition

​conditional

​not

​or

​Data

​default

​each

​path

​set

​var

​with

​String

​capitalize

​concat

​format

​datetime-format

​trim-left

​trim-one-char-right

​trim-right

​trim

​truncate

​Math

​abs

​add

​ceil

​divide

​floor

​inc

​mod

​multiply

​round

​subtract (sub)

​SendWithUs Helpers

​swu_datetimeformat

​swu_iso8601_to_time

​swu_timestamp_to_time

​translate

Whitespace Control

Courier Handlebars Helpers

Logic

and

condition

conditional

not

or

Data

default

each

path

set

var

with

String

capitalize

concat

format

datetime-format

trim-left

trim-one-char-right

trim-right

trim

truncate

Math

abs

add

ceil

divide

floor

inc

mod

multiply

round

subtract (sub)

SendWithUs Helpers

swu_datetimeformat

swu_iso8601_to_time

swu_timestamp_to_time

translate