Download attachment of item in list using REST API in SPFx

Question

I have a custom list on sharepointonline, and I have attached a file (myfile.txt) to an item (itemid=5). How can I download this attachment?

I am able download the file with this button:

<a type="button" href={'https://mydomain/Lists/Announcements/Attachments/'+this.state.ItemId+'/myfile.txt'} className="btn btn-info" download>Download Attachment</a>

I am able to get ItemId with the REST API, but there is no name of attachment files. The only question here is: How do I get the attachment file names like other columns 'Title', 'Created'? I expect 'AttachmentName', but none ofc.

Answer 1

Your REST query should be as below:

/_api/Web/Lists/getByTitle('Announcements')/items?$select=Title,Created,Attachments,AttachmentFiles&$expand=AttachmentFiles

In the JSON results, you can get the file name as below:

for (var i = 0; i < data.d.results.length; i++) {    
    var item = data.d.results[i];
    var attachmentUrl = item.AttachmentFiles.results[0];
    var fileName = attachmentUrl.FileName;
}

Answer 2

You need to either use /AttachmentFiles like this

{weburl}/_api/web/lists/getByTItle('Announcements')/Items(5)/AttachmentFiles

or expand it like this

{weburl}/_api/web/lists/getByTItle('Announcements')/Items(5)?$expand=AttachmentFiles

The / method only works on single items, where expand works with your OData query