Context Variable

Last edit: Jun 05, 2019

Context is a global object accessible in every Liquid file of the project including views, Authorization Policies, and notifications.

Displaying the context object

To inspect its structure and content, you can display the context object on the page as in the example below:

---
slug: context_example
---
{{ context }}

Context object components

context.authenticity_token


context.authenticity_token is populated by the server and automatically included in every form generated by the {% form %} tag. It is used to mitigate Cross Site Request Forgery attacks. It has to be added to the payload in all server requests other than GET.

context.constants

context.constants gives you access to sensitive data like API credentials and tokens. To protect you from leaking them, you need to explicitly call {{ context.constants }}, as they are hidden from {{ context }}. You can set constants using GraphQL mutation constant_set.

context.cookies

context.cookies returns an object with all cookies of the site.

context.current_user

context.current_user returns basic data of currently logged in user. Available attributes are: first_name, last_name, email, id and slug. It will return nil instead of object if user is not logged in.

context.device

context.device returns a hash with useful information based on UserAgent. Most notably, context.device.device_type returns one of the following: desktop, smartphone, tablet, console, portable media player, tv, car browser, camera.

context.environment

context.environment returns a string: staging or production. A common use case is to hide some functionalities on production without blocking the release.

context.flash

context.flash returns object with possible keys: alert, notice. Value for each key is a message string. Flash messages are set on form submissions.

context.headers

context.headers contains whitelisted HTTP headers with the data from the current HTTP request.

Available headers are:

  • SERVER_NAME
  • REQUEST_METHOD
  • PATH_INFO
  • REQUEST_URI
  • HTTP_AUTHORIZATION
  • HTTP_HOST
  • HTTP_USER_AGENT
  • HTTP_REFERER
  • SERVER_PORT
  • QUERY_STRING
  • X-FORWARDED-FOR
  • HTTP_STRIPE_SIGNATURE
  • HTTP_AUTHENTICATION_TOKEN

context.is_xhr

context.is_xhr returns nil for non-XHR, and Boolean true for XHR requests. A request is identified as XHR by checking if the value of the X-Requested-With header matches XMLHttpRequest.

context.language

context.language returns a String, the language ISO code used in the current request.
For more information about built-in translation mechanism go to the translations section.

context.location

context.location contains URL data of current request.

Available attributes are:

  • href
  • host
  • pathname
  • search

Example 1: Extracting params from path name with extract_url_params

URL: www.mysite.com/app/admin/content/nyc/brooklyn/main

{% assign template = '/app/admin/content/{city}/{area}/{street}' %}
{% assign params = context.location.pathname | extract_url_params: template %}

"params": {
  "city": "nyc",
  "area": "brooklyn",
  "street": "main"
}

The street is {{ context.params.street }}.

Example 2: Conditional list class

<li class="{% if context.location.href contains link.href %}active{% endif %}">
  <a href="#">{{ link.name }}</a>
</li>

context.modules

Information about the version and subscription status of installed modules.

Example: List all properties for installed modules

<section>
{% for module in context.modules %}
  Module name: {{ module[0] }}
  <table>
    <tbody>
      {% for properties in module[1] %}
        <tr>
          <th> {{ properties[0] }} </th>
          <td> {{ properties[1] }} </td>
        </tr>
      {% endfor %}
    </tbody>
  </table>
{% endfor %}
</section>

context.page

context.page contains information about the page on which it is included.

Available attributes are:


{{ context.page }}

{
  "id" => 1,
  "slug" => "foo",
  "enable_profiler" => false,
  "layout_name" => "application",
  "metadata" => {}
}

context.params

context.params contains user data provided in forms and query params.

Most common use cases are:

  • Include form data in notifications
  • Form data manipulation through default_payload
  • Data validation in Authorization Policies

Example 1: site path params mapping
When visiting the page with path www.mysite.com/app/admin/content/nyc/brooklyn/main the value of context.params would be:


{
  "slug": "app",
  "slug2": "admin",
  "slug3": "content",
  "slugs": "nyc/brooklyn/main"
}

Another way of extracting page params is using context.location.pathname as shown in Example 1.

context.session

context.session allows for quick access to session storage. Use mutations in order to store data in session like in this example

context.useragent

context.useragent returns an object with user agent data.

Example 1: Displaying useragent

{{ context.useragent }}

Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebkKit/537.36
(KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36

context.visitor

context.visitor returns an object describing browser user. For now there is only one available attribute ip.

Exposing a local variable within the context object

It is possible to promote a local variable so it is available in the context.exports namespace. Use the export tag to do that as in the following example:

{% assign foo = "bar" %}
{% export foo, namespace: "baz" %}
{{ context.exports.baz.foo }}

Questions?

We are always happy to help with any questions you may have.