Handlebars Helpers

SuprSend template editor uses handlebars templating language to add variables and support conditional content rendering in a template. You can find the list of inbuilt handlebars helpers here.

Apart from the inbuilt helper functions, we have also created some custom helper functions which you can use in template editors.

📘

Not supported in SMS and Whatsapp

Since, SMS (in India) and Whatsapp require pre-approved templates to send messages, we can't support conditional content rendering in SMS and Whatsapp templates. You can use handlebars helpers if you are sending SMS in US with vendors like Twilio and Messagebird.

SuprSend Handlebars Helpers

default

Can be used to add a default value if the variable values are "", null, undefined

Syntax:
{{default variable "default_value" }}

Example:
{{default name "user" }}

Returns:

• Variable value if the variable value is present. For instance, the above example with data {"name":"Joe"} will return Joe
• Default value if variable value is in "", null, undefined. For instance, the above example with data {"name":""}, {"name":null} or {"city":"Bangalore"} will return user

compare

Can be used to show some content in the template based on a condition. For email, you can use display condition to show or hide a particular content block

Syntax:

{{#compare name '==' "Mike"}}
true_block
{{else}}
false_block
{{/compare}}

Example:

Example-1: with else statement
{{#compare candidate_count '==' 1}}
is
{{else}}
are
{{/compare}}


Example-2: without else statement
{{#compare candidate_count '==' 1}}
is
{{/compare}}

Returns:

• Returns true_block if the condition inside compare statement returns truthy value. For instance, the above example with data {"candidate_count":1} will return is
• Returns false_block (in case else statement is present) if the condition inside compare statement returns falsy value. For instance, Example-1 with data {"candidate_count":3} will return are
• or Returns no value if the else statement is not present. For instance, Example-2 with data {"candidate_count":3} will not return anything

Supported Conditional operators in compare statement:

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Handling nested objects in handlebars

Builtin helpers and custom helpers in handlebars can only work with nested objects if the value of parent key is present. For example, {{default place.city "San Francisco"}} will return "San Francisco" only if place key is present, i.e., {"place":[]}

However, you can use the nested if condition to check if the parent is present and if so, then render nested objects value. Refer below example

{{#if place}}
  {{default place.city "San Francisco"}}
{{else}}
  San Francisco
{{/if}}


{{#if person.address}}
  {{#if person.address.current}}
    {{{default person.address.current.city "Los Angeles"}}
  {{/if}}
{{/if}}

each

You can iterate over a static or dynamic length list using each helper. Inside the block, you add the array object key which you want to iterate over.

Syntax:

{{#each array_object}}
{{variable_key}}
{{/each}}

Example:

{{#each admins}}
{{name}} 
{{/each}}

Returns:
Above example for below mock data will return steve Olivia

{
  "admins":[
    {
      "name":"steve",
      "id":"1",
      "city":"Palo Alto"
    },
    {
      "name":"Olivia",
      "id":2,
      "city":"Houston"
    }
  ]
}

datetime-format

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

Syntax:
{{datetime-format variable "format string" "timezone"}}

Examples:

{
  "date":"2023-09-26T00:00:00Z"
}

jsonStringify

Coverts any type of JSON input to a string. Can be used to print JSON and array directly in templates without having to convert it into individual strings. One of the common usecase is to pass complete JSON in Inbox template -> custom JSON field to generate custom UI.

Syntax:
{{jsonStringify variable}}

variable should be a valid JSON input.

Examples:

{
  "likes":3,
  "comments":4,
  "users":["Olivia","Steve"]
}

jsonParse

Parses a stringified JSON into a JSON object. Typically combined with jsonPath to retrieve values of internal keys in the parsed JSON, as Handlebars is a string handler and can't print JSON object directly. A common use case is handling stringified arrays in the email editor for merge tags or display conditions.

Syntax:
{{jsonParse json_string}}

variable should be a valid JSON string.

Examples:

{
  "json_string": "{\"likes\":3,\"users\":[\"Olivia\",\"Steve\"],\"comments\":4}"
}

jsonPath

Print values corresponding to internal keys in a JSON object. Often combined with jsonParse to extract and display specific values from a parsed JSON structure.

Syntax:
{{jsonPath json "path"}}

variable should be a valid JSON

Examples

{
  "json_string": "{\"likes\":3,\"users\":[\"Olivia\",\"Steve\"],\"comments\":4}",
  "nested_key":{
    "k1":"v1"
  }
}

lowercase

This handlebar helper is used to convert string to lowercase. If non string values are provided empty string '' is returned.

Syntax:
{{lowercase "string"}}

uppercase

This handlebar helper is used to convert string to uppercase. If non string values are provided empty string '' is returned.

Syntax:
{{uppercase "string"}}

capitalize

This handlebar helper is used to capitalize the first character in provided string. If non string values are provided empty string '' is returned.

Syntax:
{{capitalize "string"}}

Math Operators

add

Returns the sum of two operands. Both input values should be numbers, else it will throw an error.

Syntax:
{{add number1 number2}}

Examples:

{
  "likes":3,
  "comments":4
}

subtract

Returns the difference between two operands. Both input values should be numbers, else it will throw an error.

Syntax:
{{subtract number1 number2}}

Examples:

{
  "likes":3,
  "comments":4
}

multiply

Returns the product of two operands. Both input values should be numbers, else it will throw an error.

Syntax:
{{multiply number1 number2}}

Examples:

{
  "ARR":300,
  "billing_months":12
}

divide

Returns the quotient of the left operand divided by the right operand. Both input values should be numbers; else it will throw an error.

Syntax:
{{divide dividend divisor}}

Examples:

{
  "total_bill":3600,
  "billing_months":12
}

round

Returns the value of a number rounded to the nearest integer. The input value should be a number; else it will throw an error.

Syntax:
{{round number}}

Examples:

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.

Syntax:
{{mod dividend divisor}}

Examples:

{
  "total_bill":3600,
  "billing_months":12
}

Array Operators

unique

Returns unique items in an array

Syntax:
{{unique variable "key_string" }}

Examples:

{
  "array": [
    {
      "city": "San Francisco",
      "name": "Mike"
    },
    {
      "city": "Austin",
      "name": "Juliana"
    },
    {
      "city": "Austin",
      "name": "Nova"
    }
  ],
  "personal_details": [
    {
      "name": {
        "first_name": "john",
        "last_name": "doe"
      }
    },
    {
      "name": {
        "first_name": "mike",
        "last_name": "waz"
      }
    }
  ],
  "email": [
    "[email protected]",
    "[email protected]",
    "[email protected]"
  ]
}

itemAt

Returns item at a particular index in the array. It can be useful in scenarios where you want to display a message like liked by Mike and 3 others.

Syntax:
{{itemAt variable index }}

Examples:

{
  "array": [
    {
      "city": "San Francisco",
      "name": "Mike"
    },
    {
      "city": "Austin",
      "name": "Juliana"
    },
    {
      "city": "Austin",
      "name": "Nova"
    }
  ],
  "email":["[email protected]","[email protected]","[email protected]"]
}

Note:

This helper only works with an array of primitive data types like string, boolean, etc. If you have an array with objects in it, you can combine it with a unique helper to return the indexed value of a particular key inside the object. For instance, {{itemAt (unique array "city") 0}} in above mock will return San Francisco.

join

Concatenates all the values in an array, using a specified separator string between each value.

Syntax:
{{join variable "separator"}}

Examples:

{
  "array": [
    {
      "city": "San Francisco",
      "name": "Mike"
    },
    {
      "city": "Austin",
      "name": "Juliana"
    },
    {
      "city": "Austin",
      "name": "Nova"
    }
  ],
  "email":["[email protected]","[email protected]","[email protected]"]
}

Note:

This helper only works with an array of primitive data types like string, boolean, etc. If you have an array with objects in it, you can combine them with a unique helper to join the value of a particular key inside the object. For instance, {{join (unique array "city")}} in above mock will return San Francisco, Austin

length

Can be used to get the number of items in an array or the character length of a string. It can be useful in scenarios where you want to display a message like your post has got 100 likes.

Syntax:
{{length variable}}

Examples:

{
  "array": [
    {
      "city": "San Francisco",
      "name": "Mike"
    },
    {
      "city": "Austin",
      "name": "Juliana"
    },
    {
      "city": "Austin",
      "name": "Nova"
    }
  ],
  "email":["[email protected]","[email protected]","[email protected]"],
  "name":"Justin",
  "active":true
}

We are adding further helpers to this list. If you have a use case that is not covered, ping us on slack