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      • Attachment URL

      Introduction

      In NocoBase, Attachment URL stores an external file access address.

      It is suitable when files are already stored in an external system, object storage, or CDN and NocoBase only needs the access address. Use Attachment when NocoBase needs to upload and manage files, or URL for an ordinary web address.

      Use cases

      Attachment URL fields are suitable for these business scenarios:

      • Files hosted in external systems
      • Object-storage file addresses
      • CDN image and document addresses
      • External attachments referenced by business records

      Create and configure

      On the collection's Configure fields page, click Add field and select Attachment URL to create this field.

      Configure a Attachment URL field

      SettingDescription
      Field interfaceThe field interface. Attachment URL uses attachmentUrl, which determines how the field is entered and displayed in pages.
      Field display nameThe name displayed for the field, such as File address, Image URL, or External attachment. Use a name that business users can recognize.
      Field nameThe field identifier used internally by APIs, relation fields, permissions, and workflows. It usually cannot be changed after creation. It supports only letters, numbers, and underscores, and must begin with a letter.
      Field typeThe data-layer type. Attachment URL uses string by default.
      Default valueThe default value. When a new record has no value, NocoBase can fill this value automatically.
      Validation rulesValidation rules. Supports URL-format, length, and required validation.
      DescriptionA field description. Record the field meaning, entry requirements, data source, or maintainer.
      Note

      Field names are referenced by page blocks, permissions, workflows, and APIs after creation. Confirm the name before creating the field to avoid later configuration changes.

      Field behavior

      The default behavior of a Attachment URL field is as follows:

      BehaviorDescription
      Default Field interfaceattachmentUrl.
      Default Field typestring.
      Available Field typesstring, text.
      Page componentUses an attachment-URL component for entry and display.
      FilteringSupports URL and text filters where supported by the data source.
      SortingSupports sorting in Table blocks where supported by the data source.
      ValidationSupports URL-format, length, and required validation.

      Edit configuration

      After creation, click Edit beside the field to edit its configuration. Edit fields to adjust how they are displayed and used in NocoBase, such as the display name, description, default value, validation rules, or field-specific settings.

      When a field comes from a synchronized main-database table, editing usually maps the database field to a NocoBase Field type and Field interface.

      SettingCan be editedDescription
      Field display nameYesChanges the name displayed in the interface without changing the field identifier.
      Field nameNoThe field identifier normally cannot be changed in the edit form after creation.
      Field interfaceConditionalMain-database fields and synchronized fields can be adjusted during field mapping. Changes affect page input, display, and validation.
      Field typeConditionalMain-database fields and synchronized fields can be adjusted during field mapping. Confirm that existing values can be used by the new type first.
      Default valueYesAdjusts the default value for new records.
      Validation rulesYesAdjusts field validation rules.
      DescriptionYesAdds the field meaning, entry requirements, data source, or maintainer.
      Note

      Changing a Field type or Field interface is more than changing a display name. It affects field storage, input components, validation rules, filters, and workflow-variable usage. When the field contains substantial existing data, confirm that its data format is compatible first.

      Delete field

      Click Delete beside a Attachment URL field to delete it. You can also select multiple fields and delete them in the main data source.

      Deleting a Attachment URL field created in the main database usually also deletes the actual database column and its values. For a synchronized or external-data-source field, the impact depends on the corresponding data source and field origin.

      Warning

      Deleting a field can affect page blocks, forms, filters, permissions, workflows, APIs, imports and exports, and existing data. Confirm that the field is no longer referenced by business configuration before deleting it.

      Use in pages

      Attachment URL fields are suitable for external-file display, preview, and download.

      Use a Attachment URL field in a page

      Attachment URL configuration Attachment URL configuration

      ScenarioUse
      Form blockEnter an external file address.
      Details blockDisplay, preview, or download an external file.
      Table blockDisplay external attachment values.
      Workflows and APIsPass external file addresses to business logic.
      • Fields - Learn about field categories and mapping.
      • General collection - Create and manage fields in a collection.
      • Attachment - Upload and manage files in NocoBase.
      • URL - Store ordinary web addresses.