Upload & Categorize Files with Supabase Storage and Secure URL Generation

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              "name": "mime_type"
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            {
              "name": "binary_data_base64"
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      },
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              "type": "string",
              "value": "={{ \n  (() => {\n    const mimeType = $json.mime_type || 'application/octet-stream';\n    if (mimeType.startsWith('image/')) return 'image-files';\n    if (mimeType.startsWith('audio/')) return 'audio-files';\n    if (mimeType.startsWith('video/')) return 'video-files';\n    return 'document-files';\n  })()\n}}"
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      "notes": "Instead of the code note i would prefer to use the n8n dedicated note for this. only thing i am not sure of now is if i map the fields correct. ",
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      "parameters": {
        "options": {
          "fileName": "={{ $json.original_filename }}",
          "mimeType": "={{ $json.mime_type }}"
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        "sourceProperty": "binary_data_base64"
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        "formTitle": "test workflow form",
        "formFields": {
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            {
              "fieldLabel": "original_filename",
              "requiredField": true
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            {
              "fieldType": "textarea",
              "fieldLabel": "binary_data_base64",
              "requiredField": true
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        "formDescription": "use this form to test action workflows without having to use another workflow"
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        "content": "## 📦 Upload files to Supabase Storage\n\n- Link to [Supabase docs](https://supabase.com/docs/guides/storage)\n\nThis workflow shows how you could upload files to a Supabase Storage Instance. It's primarily designed to be called by other workflows, as there wasn't a default node for this yet, and this could be usefull in quite a lot of other workflows. \n\nIn this particular example we use mime-type to sort files to specific buckets, but this is of course dependent on your specific storage structure. \n\nThe output is a signed url for the object, to avoid having to share secrets for entire buckets to applications that need the object as input"
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      "parameters": {
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        "height": 340,
        "content": "## 🧪  Quick Test Form during building\n\n\nThis form allowed me to quickly check this flow without having to execute another workflow.\n\nOf course you could also pin data, but given the fact i wanted to check different filetypes i opted for this temporary form, you can populate the base64 field with base64 encoded string of testfile (using for example `base64 -i /path/to/file | pbcopy`)\n\n⚠️ Remove before putting flow live."
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        "content": "## ⚖️ Pro's and Con's of base64 encoding here\n\nI used the encoding step to be able to define input schema in this node below, it comes with a trade off though: file size of base 64 encoded files are 33% larger, also execution data is becoming quite large. \n\n⚠️Carefully consider if this is usable if you are working with large files. "
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        "content": "## 🔧Highlevel dataprep explanation\n\n\n**Prepare Upload Data:** maps inputs to buckets based on mimetype - passes through all other inputs.\n\n**Convert to file:** converts base64 encoded files back to actual files. (see red sticky node at start)"
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        "content": "## 🔑 About Supabase Storage\n\nSupabase Storage uses HTTP API with Bearer token authentication, not traditional AWS S3 SDK protocols.\n\nIn this set up we use an anon key/service key. We dont want to use that key all the time, so we generate a signed url to the object.\n\n⚠️ Replace the url in these nodes with your own."
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      "name": "Upload to Supabase Storage",
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      "onError": "continueErrorOutput",
      "position": [
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      "parameters": {
        "url": "=https://api-sb.janwillemaltink.com/storage/v1/object/{{ $('Prepare Upload Data').item.json.bucket_name }}/{{ $('Prepare Upload Data').item.json.original_filename }}",
        "method": "POST",
        "options": {},
        "sendBody": true,
        "contentType": "binaryData",
        "authentication": "predefinedCredentialType",
        "inputDataFieldName": "data",
        "nodeCredentialType": "supabaseApi"
      },
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        "supabaseApi": {
          "id": "rpq8Z0VD0KxUEfDd",
          "name": "Supabase account"
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      "typeVersion": 4.2
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      "parameters": {
        "url": "=https://api-sb.janwillemaltink.com/storage/v1/object/sign/{{ $json.Key }}",
        "method": "POST",
        "options": {},
        "jsonBody": "{\n\t\"expiresIn\": 2592000\n}",
        "sendBody": true,
        "specifyBody": "json",
        "authentication": "predefinedCredentialType",
        "nodeCredentialType": "supabaseApi"
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              "name": "full_signedURL",
              "type": "string",
              "value": "=https://api-sb.janwillemaltink.com/storage/v1{{ $json.signedURL }}"
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