Volt is Phalcon’s powerful and elegant template engine, designed for building dynamic and readable front-end interfaces. Its expressive syntax, built-in filters, inheritance features, and clean structure make it a favorite among developers. But like any templating system, using Volt effectively requires following certain best practices to keep your application clean, scalable, and maintainable.
This comprehensive guide covers best practices for writing clean, efficient, and organized Volt templates. Whether you are a beginner working on small apps or an advanced developer architecting large systems, this guide equips you with the principles needed to master Volt for long-term success.
1. Introduction Why Best Practices Matter in Volt
Volt can make templating intuitive and elegant, but poorly written templates can quickly lead to:
- messy view layers
- duplicated code
- difficult debugging
- slow development cycles
- inconsistent front-end structure
By following best practices, you ensure:
- a cleaner separation of concerns
- consistent template structure
- reusable components
- maintainable codebase
- scalability for large applications
- easier collaboration with teams
Volt is powerful—but it must be used wisely.
2. Maintain a Clear Separation Between Logic and Presentation
Volt is a presentation engine—not a logic processor.
2.1 Keep Business Logic Out of Volt
Bad (logic heavy):
{% set total = 0 %}
{% for item in cart %}
{% set total = total + (item.price * item.qty) %}
{% endfor %}
Good (logic handled in controller or service):
$this->view->total = $cartService->calculateTotal();
Volt should not calculate totals, process workflows, or handle domain logic.
2.2 Volt Should Only Present Data
Good practice:
- Use Volt for loops, simple conditionals, template organization.
- Use PHP (controller or service) for:
- calculations
- data transformations
- validation
- business rules
3. Prepare Data Before It Reaches Volt
Volt should work with clean, ready-to-display data.
3.1 Avoid Data Cleanup Inside Templates
Bad:
{{ product.name|trim|capitalize }}
Good:
$product->name = ucfirst(trim($product->name));
3.2 Prepare Arrays and Objects in Controllers
Only send meaningful, curated data to views.
$this->view->products = $productService->getList();
4. Keep Volt Templates Simple and Clean
Simplicity enhances clarity.
4.1 Prefer Clarity Over Cleverness
Avoid compressing logic:
{{ items|length > 0 ? 'Available' : 'Not Available' }}
Instead:
{% if items|length > 0 %}
Available
{% else %}
Not Available
{% endif %}
4.2 Keep Lines Short
Avoid overly long output statements.
4.3 Break Long Templates Into Partial Views
Which brings us to the next section…
5. Use Layouts for Global Structure
Layouts define overall page structure.
5.1 Basic Layout Pattern
layouts/main.volt:
<!DOCTYPE html>
<html>
<head>
<title>{% block title %}Default Title{% endblock %}</title>
</head>
<body>
{% block content %}{% endblock %}
</body>
</html>
5.2 Child Template
{% extends "layouts/main.volt" %}
{% block title %}Home Page{% endblock %}
{% block content %}
<h1>Welcome!</h1>
{% endblock %}
Layouts remove duplication and standardize structure.
6. Use Partials to Reuse Repetitive Components
Partials allow reusing template fragments.
6.1 Common Uses of Partials
- headers
- footers
- menus
- sidebars
- pagination
- product cards
- user profile sections
6.2 Example Partial Include
{% include "partials/menu.volt" %}
6.3 Passing Variables to Partials
{% include "partials/item.volt" with ['item': item] %}
Partials dramatically reduce template redundancy.
7. Organize Templates into Meaningful Directory Structures
A clear folder structure improves maintainability.
7.1 Standard Structure
app/views/
layouts/
partials/
users/
products/
orders/
7.2 Group Templates by Feature
Instead of placing everything in views/:
views/users/login.volt
views/users/register.volt
views/users/profile.volt
7.3 Avoid Deep Nesting
Too many nested folders make views harder to navigate.
8. Use Template Inheritance to Avoid Duplication
Laravel Blade inspired this pattern.
8.1 Declare a Master Layout
In layouts/master.volt:
{% block content %}{% endblock %}
8.2 Extend the Master in Pages
{% extends "layouts/master.volt" %}
8.3 Override Blocks of Content
This pattern:
- organizes views
- prevents duplication
- ensures that layouts are consistent
9. Keep Conditions and Loops Minimal
Volt supports loops and conditionals, but they should be presentation-level only.
9.1 Good Conditional
{% if user %}
Hello, {{ user.name }}
{% endif %}
9.2 Bad Conditional
{% if user.role == 'admin' and user.active == true and userPermissions|length > 3 %}
Complex expressions belong in:
- controller
- middleware
- service
9.3 Keep Loops Simple
Avoid calculations inside loops.
10. Use Filters Wisely and Sparingly
Filters transform output—but overusing them creates clutter.
10.1 Common Useful Filters
{{ name|upper }}
{{ email|lower }}
{{ content|striptags }}
{{ escaped|escape }}
10.2 Avoid Using Filters for Business Logic
Bad:
{{ price|add_tax }}
Better:
$this->view->priceWithTax = $taxService->apply($price);
10.3 Avoid Chaining Too Many Filters
{{ username|trim|upper|escape|default('Guest') }}
Break such transformations into controller-level logic.
11. Use Custom Filters Only When Absolutely Necessary
Volt allows custom filters—but overuse makes templates harder to understand.
11.1 Example of Custom Filter
$compiler->addFilter('slugify', function ($resolved) {
return "slugify($resolved)";
});
11.2 When to Use Custom Filters
- string formatting
- display-specific logic
11.3 When NOT to Use Custom Filters
- business logic
- heavy transformation
- data queries
12. Keep Volt Templates Free of PHP
Volt must not act as a PHP engine.
12.1 Avoid Embedding PHP
Bad:
<?php echo $price; ?>
Instead:
{{ price }}
12.2 Avoid Function Overuse
Limit function calls inside Volt.
13. Avoid Massive Templates: Break Into Components
Large templates should be broken into parts.
13.1 Example Structure
product/
list.volt
card.volt
filter.volt
13.2 Components Keep Templates Modular
- easier to edit
- better reuse
- cleaner structure
14. Use Macros for Repeated HTML Blocks
Macros act like template functions.
14.1 Example Macro
{% macro input(name, type) %}
<input type="{{ type }}" name="{{ name }}">
{% endmacro %}
14.2 Use Macro
{{ input("email", "email") }}
Macros:
- reduce duplication
- help build reusable components
- simplify forms
15. Limit Logic in Volt Loops
Complex loops violate separation of concerns.
15.1 Bad Loop
{% for user in users if user.isActive and user.role != 'admin' %}
15.2 Good Loop
Filter users in controller:
$users = $userService->listActiveNonAdmins();
Then loop:
{% for user in users %}
16. Use Switch Statements Cleanly
Volt supports switch-case.
16.1 Example
{% switch user.role %}
{% case 'admin' %} Admin User
{% case 'editor' %} Editor
{% default %} Guest
{% endswitch %}
Switch statements are cleaner than nested ifs.
17. Avoid Outputting Raw Data Without Escaping
Volt escapes automatically.
17.1 Use Raw Carefully
{{ html|raw }}
Use only for:
- safe HTML
- sanitized content
Never use raw on user-submitted data.
18. Use JSON Output Carefully
Volt can output JSON for JS usage.
<script>
let config = {{ config|json_encode|raw }};
</script>
Always use raw after encoding to avoid double escaping.
19. Keep Client-Side Logic in Separate JS Files
Do not embed large JavaScript blocks inside Volt.
- use
assets manager - use external
.jsfiles
Volt should remain presentation-focused.
20. Organize CSS and JavaScript Loading Through Layouts
Use a layout to manage:
- CSS imports
- JS imports
- meta tags
- title and SEO attributes
Avoid repeating asset links in multiple templates.
21. Comment Templates Meaningfully
Volt supports comments:
{# This section prints user list #}
Comments improve:
- readability
- team collaboration
But avoid over-commenting.
22. Make Templates Consistent Across the Application
Use a naming and formatting standard:
- consistent indentation
- consistent block naming
- uniform directory structure
Consistency improves maintainability.
23. Handle Empty States Gracefully
Volt should gracefully handle missing data.
23.1 Example
{% if items is empty %}
<p>No items found.</p>
{% else %}
{% for item in items %}
{{ item.name }}
{% endfor %}
{% endif %}
Empty-state handling improves user experience.
24. Keep Your Views Free of Side Effects
Volt templates should not:
- modify data
- write to session
- handle form validation
- run heavy logic
They should focus purely on presentation.
25. Move Repetitive HTML to Partials or Macros
Avoid writing the same markup repeatedly.
25.1 Example Repetitive HTML
<div class="product">
<h3>{{ product.name }}</h3>
<p>{{ product.price }}</p>
</div>
25.2 Convert to Partial
partials/product-card.volt
<div class="product-card">
<h3>{{ product.name }}</h3>
<p>{{ product.price }}</p>
</div>
Then:
{% include "partials/product-card.volt" with ['product': product] %}
26. Test Templates with Sample Data
While developing, pass test data from controllers.
$this->view->items = ['apple', 'banana'];
Testing ensures templates don’t break with edge cases.
27. Avoid Overusing Includes
Includes help—but too many can slow readability.
- group related includes
- avoid deeply nested partial chains
28. Document Complex View Logic
When a view uses conditionals or loops, document them clearly.
{# If the user is premium, show premium dashboard #}
{% if user.premium %}
Documentation prevents confusion later.
29. Keep Logic in Services or Controllers, Not in Volt
Volt should only read and display.
Example:
Bad:
{% if posts|length > 20 %}
Good:
$this->view->manyPosts = $postService->hasManyPosts();
Volt:
{% if manyPosts %}
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