Best Approach to Updating Attachments in SharePoint via K2 Form

When editing a form with attachments already loaded from SharePoint, the key is to distinguish between the initial load of existing attachments and genuine user-initiated changes. Rather than deleting and re-uploading every attachment on every edit, you can implement a more targeted approach.

Recommended Approach

1. Flag or Track Changes:
   Instead of relying on the file control’s “raise action” event—which fires during the initial load—you can introduce a flag (or a hidden field) that indicates when a user has actually modified a file control. For example, the flag would only be set when the user explicitly selects a new file.

2. Compare Original and New Data:
   When the form is loaded, store the original file metadata (such as file name, size, or an identifier) in a hidden field or variable. Upon submission, compare the current file control’s value with the stored original. Only if there’s a difference should you trigger an update for that specific attachment.

3. Update Only Changed Attachments:
   For each attachment control, if a change is detected:

   • If a file is replaced: Call the SmartObject’s UploadDocuments function to update the file.
   • If a file is removed: You might need to call a delete function or adjust your SharePoint record accordingly.
   • If no change is detected: Leave the existing attachment untouched.

4. Manage Initial Data Load:
   Use a form-level flag (like “IsFormLoaded”) that’s set only after the form has fully loaded from SharePoint. Modify your rules so that the “control raised an action” event only acts if this flag indicates the form is no longer in its loading phase. This prevents the event from triggering on initial data retrieval.

Step-by-Step Implementation

• On Form Load:

  • Retrieve and display existing attachments.
  • Store relevant attachment metadata (e.g., file names, IDs) in hidden fields.
  • Set a flag (e.g., IsFormLoaded = true) once all initial data is loaded.

• On File Control Change:

  • Check if IsFormLoaded is true. If it is, then the change is likely user-initiated.
  • Set a secondary flag for that specific file control to indicate it has been modified (e.g., Attachment1Changed = true).

• On Form Submission:

  • For each attachment control, check if its “changed” flag is set.
  • For changed attachments, call the SmartObject’s UploadDocuments method.
  • For unchanged attachments, simply leave the SharePoint record as is.

Hi ​@N-I-1990 has this reply answered your question?