Untangling the Mysteries of Shopify Image Upload Errors: A Journey Through Code

Some time ago, we were knee-deep in code, meticulously crafting an experience, conjuring little bits of magic to make our Shopify store sing. Or at least, that was the plan. But you know how it goes—plans and reality are often at odds, especially when it comes to technology.

One fateful evening, much like a weary traveler pausing to admire an elusive sunset, we attempted to upload an image. Ah, simple moments of joy! But wait, what’s this? An error, stealthy as a shadow, slipped through unseen cracks until it stood proudly in our process. We had a "Procession Error" right in our face.

"Joy_Matubber_0-1735672550951.png," yep, that was the culprit's calling card. But fear not, dear code warriors, we're here to unravel this enigma together, one step at a time, until this file upload nightmare becomes merely a slightly-mostly-funny story to tell your Shopify friends.

Diverging from the Path: Locating Our Bug

Let's picture ourselves back into that harrowing scene. The code before us is supposed to work flawlessly—it should have, in theory, had it not been for this curious misconception lurking in the shadows. Our serene image upload functionality found itself caught in the tangled vines of the "Procession Error."

Step 1: Check Your Session Parameters

First and foremost:

const shop = req?.query?.shop
if (!shop) {
  throw new Error('Missing shop parameter in the request query.')
}

We ought to double-check that our shop parameter isn't AWOL. Without our trusty shop guiding us, we are invariably lost at sea. No parameter, no image—just a recipe for heartbreak.

Step 2: Tame the Beast - Access Token Exodus

Should you find yourself in epochal desolation with no access token on your session (session.accessToken being null or undefined—perish the thought!), we must breathe life back into our logic. This session needs a talking to, for without this token, havoc will ensue.

Step 3: File Naming Conundrums

Smell something fishy in the state of file names? You might want to confirm:

const variables = {
  filename: req.body.name, // Correct field name (lowercase "n")
  mimeType: req.body.type,
  httpMethod: 'POST',
  resource: 'FILE',
}

if (!variables.filename || !variables.mimeType) {
  throw new Error("Missing required fields: 'filename' or 'mimeType'.")
}

The filename and mimeType—yep, quintessential presences in this tale. Without them, file uploads are just dreams, adrift on the sea of hopefulness.

Beginning the Ritual: The GraphQL Inquiry

With solemn reverence, we call upon the ancient incantations of GraphQL:

const fileUploadQuery = () => {
  return `
    mutation stagedUploadsCreate($input: [StagedUploadInput!]!) {
      stagedUploadsCreate(input: $input) {
        stagedTargets {
          url
          resourceUrl
          parameters {
            name
            value
          }
        }
      }
    }
  `
}

Prepare the sacrificial session and variables, for this spell requires precision and utter belief in our code’s potential.

Step 4: Execute with Finesse

Venture further with the aid of our loyal sidekick, the GraphQL client:

const client = new shopify.api.clients.Graphql({
  session: session,
})

try {
  const response = await client.query({
    data: {
      query: fileUploadQuery(),
      variables: { input: [variables] },
    },
  })

  return response.body.data.stagedUploadsCreate.stagedTargets
} catch (error) {
  console.error('GraphQL lamentations:', error.response || error.message)
  throw new Error('Failed to execute stagedUploadsCreate mutation')
}

Ward off errors with vigilant consistency, and—should misfortune persist—debug further to ensure that each API call is granted its correct expectations.

Concluding the Expedition: Final Words

If you find yourself weaving through Shopify's labyrinthine corridors, fret not. We've traversed these tangled paths together. As with any great adventure, perseverance accompanies triumph, and if all else fails—a cup of tea might be in order.

Isn’t it something? Awakening to the reality that behind every labyrinth and code bug, solutions await us with patience and calm. Our missteps become lessons in the overarching journey to mastering Shopify. May your spirits be high and your internet speedy as you conquer the elusive "Procession Error," emerging victorious with uploads dancing joyfully in file sections—all thanks to our guide's help.