Debugging
When working with Twig templates in ShopWired, encountering errors is a common part of the development process.
On ShopWired, if there is a problem in your Twig template, the page on your website will typically load as a 404 error. This can make pinpointing and resolving issues more challenging, so understanding the debugging tools available in Twig is essential.
Common issues and how to debug them
404 error due to Twig syntax errors
When you see a 404 error on a page where you expect your template to render, it often indicates a syntax error or an issue within the Twig template. Here's how to start debugging:
- Check your Twig syntax Ensure that all your tags, filters, and functions are correctly formatted. Missing closing tags (
{% endblock %},{% endif %}, etc.) or incorrectly nested blocks are common causes of errors. - Use the
dumpfunction: Thedumpfunction in Twig is a useful tool for inspecting variables and understanding what data is available in your template. You can use it to output the value of a variable directly into your template for debugging purposes.{% set product = null %}{{ dump(product) }}- If
productisnullor not what you expected, thedumpfunction will show you this directly in your template (if the template loads correctly).
- If
- Test in small increments: If you suspect a specific section of your template is causing the issue, try commenting out sections of your code and reintroducing them piece by piece. This can help you isolate the error.
{# {% include 'header.twig' %} #}<p>Test content</p>{# {% include 'footer.twig' %} #}- By commenting out the includes, you can determine if the issue is related to these files or something else in your template.
- Check for missing variables or functions: Ensure all variables and functions you are using are correctly defined and available in the scope of your template. If you try to access a variable that doesn’t exist, it could lead to errors.
{{ product.title }} {# Ensure 'product' is defined and has a 'name' attribute #}- If
productis undefined ornamedoes not exist, this can cause the page to fail silently, resulting in a 404.
- If
Handling missing variables
Another common issue is referencing variables that don’t exist. Ensure all variables are correct:
{% if product.price is defined %}
{{ product.price }}
{% else %}
<p>Price not available</p>
{% endif %}
This conditional check can prevent the template from failing if the asset path is incorrect or the file is missing.
Using `dump` in a ShopWired context
While dump can be an effective debugging tool, remember that it should be removed from your templates once you’ve resolved the issue. Leaving dump statements in your code could expose unnecessary information or slow down your pages.
{% set user = { name: 'John Smith', email: 'john@example.com' } %}
{{ dump(user) }}
After debugging, remove or comment out the dump statement:
{# {{ dump(user) }} #}
Testing in a staging environment
Before making changes live, test your templates in a staging environment using a .
This allows you to catch errors without affecting your live site. Once you’re confident the templates work as expected, you can deploy them live.
