Issue with getAttachmentContentAsync when trying to fetch inline image attachment content

Hello Marjolein Bente,

I wanted to check in again since I haven’t heard back regarding the solution I've shared. I’m here to help if you’re still experiencing issues or need any additional clarification.

If the previous approach didn’t fully resolve your concern, I’d be happy to explore alternative options with you.

Hello,

Thank you for your reply and patience. As I was going through the code again to create a shareable version, I discovered some of my previous statements were incorrect. Even if the function does not have to await an API call, but instead goes straight to a state set function, this issue occurs. We call many similar state set functions, so I'm not sure why this one specifically might cause the issue.

We have a substantial amount of logic running on the ItemSend event, I've extracted the bits relevant to the inline attachments here. I will add the subcomponent and Office. initialize later.

onsend.js
async function send(mailBodyText, other) {
	// Some state validation
	try {
		// Convert attachments to inline base64
		mailBodyText = await InlineAttachmentConverter.convertAttachments(
			mailBodyText
		);
		// Processing mail body and eventually send item
	} catch (error) {
		// catch block
	}
}
async function convertAttachments(htmlBody) {
	// Some validation check
	try {
		const inlineAttachments =
			await AttachmentManager.fetchEmailInlineImages();
		htmlBody = await convertOfficeAttachmentsToBase64(
			htmlBody,
			inlineAttachments
		);
		// This is where the issue occurs
		htmlBody = await convertInlineImagesToBase64(
			htmlBody,
			inlineAttachments
		);
	} catch (error) {
		// catch block
	}
	return htmlBody;
}
// This succeeds, getAttachmentsAsync retrieves the inline image data
async function fetchEmailInlineImages() {
	const mailItem = Office.context.mailbox.item;
	return new Promise((resolve, reject) => {
		mailItem.getAttachmentsAsync({}, (result) => {
			if (result.status !== "succeeded") {
				reject("Failed to get inline attachments");
			} else {
				const itemAttachments = [];
				result.value.forEach((attachment) => {
					if (attachment.isInline) {
						attachments.push(attachment);
					}
				});
				resolve(itemAttachments);
			}
		});
	});
}
async function convertInlineImagesToBase64(htmlBody, inlineImageAttachments) {
	try {
		// check for attachments
		// Process each cid image in the HTML body
		while (true) {
			// A bunch of looping through the html body to extract the image id
			if (inlineImageAttachment) {
				try {
					// This is where the issue occurs
					const inlineImageAttachmentContent =
						await AttachmentManager.retrieveAttachmentData(
							inlineImageAttachment.id
						);
					if (inlineImageAttachmentContent.format === "base64") {
						// image processing
					}
				} catch (error) {
					// catch block
				}
			} else {
				// error logging
			}
			// continue looping through the html body
		}
		// Remove the attachments now that they're embedded in the html
	} catch (error) {
		//catch block
	}
	return htmlBody;
}
async function retrieveAttachmentData(attachmentId) {
	const mailItem = Office.context.mailbox.item;
	return new Promise((resolve, reject) => {
		mailItem.getAttachmentContentAsync(attachmentId, (result) => {
			if (result.status !== "succeeded") {
				reject("Failed to get inline attachment content");
			} else {
				// The result.status is succeeded but the result.value.content is empty
				resolve(result.value);
			}
		});
	});
}