Expressions

Syntax for using basic JavaScript to manipulate data in HTML emails

Handlebars-like, curly brace expression syntax is supported, allowing you to access variables from your Environment config or from a Template’s Front Matter:

emails/example.html

---
title: Example
---

<x-main>
  The title is: {{ page.title }}

  You ran the `maizzle build {{ page.env }}` command.
</x-main>

Running maizzle build production would render this HTML:

The title is: Example

You ran the `maizzle build production` command.

You may use basic JavaScript expressions within curly braces:

emails/example.html

<x-main>
  doctype is {{ page.doctype || 'not set' }}
  this email {{ page.env === 'production' ? "is" : "isn't" }} production ready!
</x-main>

Running maizzle build, we would get:

doctype is not set
this email isn't production ready!

Unescaping

By default, special characters are escaped when using two curly braces:

emails/example.html

---
markup: '<strong>Bold</strong>'
---

<x-main>
  {{ page.markup }}
  <!-- Result: &lt;strong&gt;Bold&lt;strong&gt; -->
</x-main>

If you need to render values exactly as they are, use triple curly braces:

emails/example.html

---
markup: '<strong>Bold</strong>'
---

<x-main>
  {{{ page.markup }}}
  <!-- Result: <strong>Bold</strong> -->
</x-main>

Ignoring

Other templating engines and many ESPs also use the {{ }} syntax.

If you want to prevent expression compilation and actually render the curly braces so you can evaluate them at a later stage, you have several options.

Undefined variables

First, it’s important to note that any undefined variable will simply be output as-is, so you don’t need to do anything special if you want to ignore an expression containing a variable that doesn’t exist in your Environment config or Front Matter:

emails/example.html

<x-main>
  {{ undefinedVariable }}
</x-main>

Result:

build_production/example.html

{{ undefinedVariable }}

Ignore inline

The Blade-inspired @{{ }} syntax is useful for one-offs, where you need to ignore a single expression which contains variables that you also have defined in your Maizzle project. The compiled email will render {{ }} without the @.

For example, if you actually want to render {{ page.title }} instead of evaluating it:

emails/example.html

---
title: 'Weekly newsletter'
---

<x-main>
  @{{ page.title }}
  <!-- Result: {{ page.title }} -->
</x-main>

This can also be used to avoid encoding entities inside the expression:

emails/example.html

<x-main>
  {{ $foo->bar }}
  <!-- Result: {{ $foo-&gt;bar }} -->

  @{{ $foo->bar }}
  <!-- Result: {{ $foo->bar }} -->
</x-main>

Ignore in Front Matter

You may also use @{{ }} to ignore expressions in Front Matter.

emails/example.html

---
title: "Weekly newsletter no. @{{ 1 + 1 }}"
---
<x-main>
  {{ page.title }}
</x-main>

Result:

build_production/example.html

Weekly newsletter no. {{ 1 + 1 }}

Again, this is just to avoid Maizzle from evaluating the expression - you don’t need the @ if your expression contains a variable that doesn’t exist in your Environment config or Front Matter:

emails/example.html

---
title: "Weekly newsletter no. {{ editions.count }}"
---

<x-main>
  {{ page.title }}
</x-main>

Result:

build_production/example.html

Weekly newsletter no. {{ editions.count }}

Ignore with <raw>

Use <raw> to ignore expressions or any PostHTML tags in a block of HTML:

emails/example.html

<raw>
  <p>The quick brown {{ 1 + 2 }} jumps over the lazy {{ 3 + 4 }}.</p>
  <each loop="i in [1,2]">Test</each>
</raw>

<raw> will be removed in the final output, but the curly braces will be left untouched:

build_production/example.html

<p>The quick brown {{ 1 + 2 }} jumps over the lazy {{ 3 + 4 }}.</p>
<each loop="i in [1,2]">Test</each>

Maizzle components, like <x-button>, are not ignored inside <raw> and will be compiled as usual.

Change delimiters

You can change the delimiters to something else, like [[ ]]:

config.js

export default {
  posthtml: {
    expressions: {
      delimiters: ['[[', ']]'],
      unescapeDelimiters: ['[[[', ']]]']
    }
  }
}

Then you can safely use {{ }} and it will not be evaluated:

emails/example.html

---
title: "Weekly newsletter"
---

<x-main>
  [[ page.title ]]
  <!-- Result: Weekly newsletter -->

  {{ page.title }}
  <!-- Result: {{ page.title }} -->
</x-main>