getAttachmentById

This function retrieves an attachment file as a Blob object using its unique ID. This is useful when you already know the specific attachment ID you want to retrieve, either from a previous query or from metadata stored in your application.

Syntax

app.getAttachmentById(attachmentId)

Parameters

Parameter	Type	Description
attachmentId	Number	The unique ID of the attachment to retrieve

Return Value

Returns a Promise that resolves to:

• A Blob object containing the file data if the attachment exists
• null if the attachment cannot be found or retrieved

Examples

Example 1: Basic usage to retrieve and show an attachment:

// Get an attachment with ID 1234
const pdfBlob = app.getAttachmentById(1234);

// Display the content in a document viewer
app.showBlob("documentViewer", pdfBlob);

Example 2: Retrieving and printing an invoice attachment:

// Get all attachments for the current record
const allAttachmentsForThisRecord = app.getAttachmentsForCurrentRecord();

// Filter to find invoices (assuming document type ID 2 represents invoices)
const invoices = allAttachmentsForThisRecord.filter(singleAttachment => {
  return singleAttachment.documentTypeId == 2
});

// Get the first invoice as a blob
const attachmentBlob = app.getAttachmentById(invoices[0].id);

// Print the invoice
app.printBlob(attachmentBlob);

Example 3: Retrieving and downloading an attachment:

// Get the attachment with ID 5678
const blob = app.getAttachmentById(5678);

// Use the saveBlob helper function to prompt the user to download it
saveBlob(blob, "document.pdf");

Notes

• This function is often used in combination with getAttachmentsForCurrentRecord() to first find the IDs of attachments and then retrieve specific files
• For retrieving attachments by filename rather than ID, use getAttachmentByFileName()
• When working with a large number of attachments, it may be more efficient to use getAttachmentInfoById() first to retrieve metadata without downloading the actual file
• The function returns a standard JavaScript Blob object that can be used with various browser APIs