Mechanic
đŸ“Ŗ Shopify REST Deprecation
  • â›Šī¸Introduction
  • 🤓Hire a Mechanic developer
  • đŸ’¯status.mechanic.dev
  • đŸ“ŖShopify is deprecating the REST API
  • 🙋"I need something custom!"
  • 🧑‍đŸ’ģ"I need help with my custom task!"
  • 🤖"I need help with my AI-written task!"
  • Resources
    • âŦ‡ī¸Install Mechanic
    • 🧑‍đŸ’ģTask library
      • Contributing
      • Requesting
    • 🚀Slack community
    • 🤝Partner directory
    • 🧠Tutorials
      • Video walkthroughs
        • Auto-tag orders by originating staff member
        • Maintain a tag for orders processed today
        • Auto-tag orders with their tracking numbers
        • Sync inventory for shared SKUs
        • Auto-tag products when their SKU(s) change
        • Auto-publish new products
        • Email a report of customers who haven't ordered in X days
        • Upgrading a Mechanic task: Adding a time delay
        • Email the customer when tracking numbers are added to their order
        • Adding an optional time delay to your Mechanic task
        • Delete all orders
        • Send an email when a specific product is shipped
        • Send recurring reminders about unpaid orders
        • Send an email when a product's price goes below its cost
        • Auto-tag customers by sales channel
        • Creating products in bulk
      • Creating a Mechanic webhook
      • Practicing writing tasks
      • Triggering tasks from a contact form
      • Creating scheduled CSV feeds
      • Fetching data from a shared Google sheet
    • 🏆Converting tasks from Shopify REST to GraphQL
      • Conversion: Single resource lookups
      • Conversion: Resource loops to paginated queries
      • Conversion: Connections from a resource
      • Conversion: Metafield lookups from a resource
      • Conversion: Resource lookups in task option fields
  • Core Concepts
    • Events
      • Topics
      • Parent and child events
    • Tasks
      • Subscriptions
      • Code
        • Environment variables
        • Action objects
        • Error objects
        • Log objects
      • Options
        • Custom validation
      • Previews
        • Defining preview events
        • Stub data
      • Shopify API version
      • Advanced settings
        • Documentation
        • JavaScript
        • Perform action runs in sequence
      • Import and export
      • User Form
    • Actions
      • Cache
      • Echo
      • Email
      • Event
      • Files
      • Flow
      • FTP
      • Google Drive
      • Google Sheets
      • HTTP
      • Integrations
        • Report Toaster
      • Shopify
      • File generators
        • Base64
        • PDF
        • Plaintext
        • URL
        • ZIP
    • Runs
      • Scheduling
      • Concurrency
      • Ordering
      • Retries
    • Interacting with Shopify
      • Responding to events
        • Reconciling missing events
      • Reading data
        • âš ī¸Liquid objects
        • 🏆GraphQL in Liquid
        • Bulk operations
        • The Shopify action
      • Writing data
      • Shopify admin action links
      • API rate limit
      • API versions
  • Platform
    • 🔆Policies
      • Data
      • Plans
      • Pricing
      • Privacy
    • Cache
      • Cache endpoints
    • Email
      • Receiving email
      • Custom email addresses
      • DMARC
      • Email templates
    • Error handling
    • Events
      • Event topics
      • Event filters
    • GraphQL
      • Basics
        • Shopify Admin API GraphiQL explorer
        • Queries
        • Mutations
        • Pagination
      • Bulk operations
    • Integrations
      • Appstle Subscriptions
      • Google Drive and Google Sheets
      • Judge.me
      • Locksmith
      • Report Toaster
      • Shopify Flow
      • Run links
    • Liquid
      • Basics
        • Syntax
        • Data types
        • Variables
        • Comments
        • Filters
        • Operators
        • Control flow
          • Condition
          • Iteration
        • Whitespace
      • Liquid console
      • Mechanic filters
        • Deprecated filters
      • Mechanic keyword literals
        • array
        • hash
        • newline
      • Mechanic objects
        • Action object
        • Cache object
        • Event object
        • Options object
        • Task object
        • âš ī¸Shopify REST Admin API
          • đŸšĢArticle object
          • đŸšĢBlog object
          • đŸšĢCollection object
          • đŸšĢCustomer object
          • đŸšĢDiscount code object
          • đŸšĢDispute object
          • đŸšĢDraft order object
          • đŸšĢFulfillment object
          • đŸšĢFulfillment order object
          • đŸšĢFulfillment event object
          • đŸšĢGift card object
          • đŸšĢInventory item object
          • đŸšĢInventory level object
          • đŸšĢLine item object
          • đŸšĢLocation object
          • đŸšĢMetafields
            • Metafield object
            • Metafield representation object
            • Metafield collection object
          • đŸšĢOrder object
          • đŸšĢOrder risk object
          • đŸšĢPrice rule object
          • đŸšĢProduct object
          • đŸšĢProduct image object
          • đŸšĢRefund object
          • đŸšĢShipping zone object
          • đŸšĢShop object
          • đŸšĢTheme object
          • đŸšĢTheme asset object
          • đŸšĢTransaction object
          • đŸšĢVariant object
      • Mechanic tags
        • liquid
        • action
        • assign
        • error
        • log
      • Mechanic code snippets
    • Shopify
      • Custom authentication
      • "Read all orders"
    • Webhooks
  • Techniques
    • Preventing action loops
    • Writing a high-quality task
    • Tagging Shopify resources
    • Debouncing events
    • Responding to action results
    • Working with external APIs
      • JSON Web Signatures
      • AWS request signatures
    • Finding a resource ID
    • Migrating templates from Shopify to Mechanic
    • Securing Mechanic webhooks
    • Monitoring Mechanic
  • FAQ
    • The app isn't loading. What do I do?
    • How do I stop a large batch of runs?
    • A Shopify event is missing. Where is it?
    • Does Mechanic have an affiliate program?
    • Can non-owners install Mechanic?
    • Can I replace Shopify's order emails with Mechanic?
    • Can I manually set Shopify permissions for Mechanic?
    • Does my theme need to be updated for Mechanic?
    • Do you have a plan for development stores?
    • Why don't I see any events in my task's activity?
    • Can I read data back from my webhook submission?
    • My task added a tag, but now the tag is missing – why?
    • How do I add an unsubscribe link to my emails?
    • How do I send images with my emails?
    • Can I re-send order confirmation emails with Mechanic?
    • Why am I seeing a different price than on the app store?
    • Do you have a Partner-friendly plan?
    • Why are my tasks delayed or not running?
    • My task is failing because of a permissions problem. Why?
    • How do I preview email attachments?
    • Can I query external APIs?
    • Why can't I access the Shopify API during preview mode?
    • How do marketing preferences work with Mechanic?
    • Can I send data to Google Sheets?
    • What's possible with timeline comments?
    • I'm getting a "query param length is too long" error when using GraphQL.
    • Can my Mechanic concurrency limit be raised?
    • What IP address does Mechanic use?
    • Can Mechanic read or manage customer subscriptions?
    • Why is everything harder now?
    • Can task content be translated into multiple languages?
    • Can I add a time delay to my task?
    • Can I add another store to my existing Mechanic subscription?
    • How can I reduce memory usage of my task?
    • How do I connect PayPal to Shopify with Mechanic?
    • How do I add a Shopify access scope to my task?
    • Can I have my Mechanic data retained for more (or less) than 15 days?
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Important Updates

  • đŸ“Ŗ Shopify REST Deprecation
On this page
  • What it's for
  • How it works
  • Mechanic tags
  • Block usage
  • Inline usage

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  1. Platform
  2. Liquid
  3. Mechanic tags

liquid

PreviousMechanic tagsNextaction

Last updated 9 months ago

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The liquid tag is used for writing multiple Liquid expressions within a single tag.

It's not a Mechanic invention; this tag is a part of open-source Liquid (see ). But because Mechanic introduces several new tags of its own, it's worth talking about liquid and how it can be used in Mechanic code.

What it's for

Typically, Liquid code is embedded within some larger context.

In Shopify's Online Store theme templates, for example, the code you write is treated as browser-ready HTML (or CSS, or JavaScript, etc) until you type {% ... %} or {{ ... }}. Within those markers, you're in the world of Liquid. Everything outside of those markers remains static. And, once the Liquid code is evaluated, its output gets added to that static content, resulting in one cohesive set of output. Since we're talking about Online Store templates, the output eventually makes its way to the web browser, where the resulting HTML/CSS/JS/etc is rendered – and the web browser never has to know Liquid was involved.

In Mechanic's task code, the code you write is assumed to contain a stream of JSON objects. Everything is assumed to be valid JSON until you type {% ... %} or {{ ... }}. Within those markers, you're in the world of Liquid. Everything outside of those markers remains static. And, once the Liquid code is evaluated, its output gets added to that static content, resulting in one cohesive set of output. Since we're talking about Mechanic task code, the output eventually makes its way to Mechanic's run system, where the resulting stream of JSON objects is used to construct actions to be performed – and those actions never have to know Liquid was involved.

This nested way of doing Liquid (some other language on the outside – like HTML or JSON – and Liquid on the inside) works well when most of the code is in that outside language. When most of your code is Liquid itself, the {% ... %} and {{ ... }} markers start to get in the way.

This is where the liquid tag comes in. Within {% liquid ... %}, you can write line after line of pure Liquid expressions, without ever having to return to the outside language.

How it works

The liquid tag opens up an alternative Liquid parsing mode, in which each line of code within the tag is evaluated as if each line was wrapped in its own {% ... %} markers.

This means that two pieces of Liquid are equivalent:

{% echo "hello!" %}

{% liquid
   echo "hello!"
%}

The liquid tag is useful when you're doing lots of Liquid statements, and when your code can be expressed in 100% Liquid, without having to rely on non-Liquid static content.

Mechanic tags

Block usage

Typical block usage looks like this, using the action tag as an example:

{% action "email" %}
  {
    "to": "hello@example.com"
  }
{% endaction %}
{"action":{"type":"email","options":{"to":"hello@example.com"}}}

These next two examples use the liquid tag to achieve exactly the same behavior: some static JSON content, passed up to the "parent" action tag. Both of the Liquid examples below produce the JSON output shown above.

{% liquid
  action "email"
    echo '{"to": "hello@example.com"}'
  endaction
%}
{% liquid
  action "email"
    assign payload = hash
    assign payload["to"] = "hello@example.com"
    echo payload | json
  endaction
%}

Inline usage

The action, error, and log tags all have an inline usage as well. Typical inline usage looks like this, using the log tag as an example:

{% log "oh my!" %}

The action tag supports a type argument; simple inline usage might look like this:

{% assign payload = hash %}
{% assign payload["to"] = "hello@example.com" %}
{% action "email", payload %}

Here's how these examples work using the liquid tag:

{% liquid
  log "oh my!"

  assign payload = hash
  assign payload["to"] = "hello@example.com"
  action "email", payload
%}

And here's the output:

{"log":"oh my!"}
{"action":{"type":"email","options":{"to":"hello@example.com"}}}

Mechanic Liquid adds several tags that are relevant here: , , and . All three of these tags support block usage and inline usage.

In the example above, the interior of the action tag is static content. The Liquid engine sees the {% action "email" %} lines, and it knows that more content is coming. So, it puts the Email action aside temporarily, and gathers all the content that follows, ending right before the closing {% endaction %} tag. Once endaction arrives, all the content in the middle is handed back to the Email action, which generates the final . The final output looks like this:

documentation
action
error
log
action JSON object