How do I get list items' attached files with CAML via REST API?

Question

I'm retrieving items from a list. The list contains entries which have attachments. Can I modify my query to include the attachment URLs? What's the most efficient way of doing this?

<View>
<Query>
<Where><Eq><FieldRef Name='Special' /><Value Type='Boolean'>1</Value></Eq></Where>
<OrderBy><FieldRef Name='News_x0020_Date' Ascending='FALSE' /></OrderBy>
</Query>
<RowLimit>5</RowLimit>
</View>

Answer 1

IncludeAttachmentURLs is not available with CAML query object of .NET Client object model. To retrieve the files from the attachment field you have to try the following:

Folder folder = clientContext.Web.GetFolderByServerRelativeUrl(
spList.RootFolder.ServerRelativeUrl + "/Attachments/" + item.Id);    
FileCollection files = attFolder.Files;    
// If you only need the URLs    
ctx.Load(files, fs => fs.Include(f => f.ServerRelativeUrl));    
ctx.ExecuteQuery();

The attachments are not stored in the list item but stored in a sub folder named "Attachments" and if this item has one or more attachments then a folder is created with the name as Id of the item where all the attachments for that item are stored.So , in the above code we are retrieving all the items for the folder which has the attachments

Reference

Answer 2

The "Include attachment urls" section of this article may provide you help with what you want to achieve.

Let us know if it helped.

Answer 3

Although the IncludeAttachmentURLs option is really not available via the client object model (at least in version 2013), you can still use the "good-old" SharePoint Web Services to submit a CAML query including this option if you need to work from the client side, as described here:

$(document).ready(function() {
querySPWebServices();
});

function querySPWebServices() {
        var soapEnv = "<soapenv:Envelope xmlns:soapenv='http://schemas.xmlsoap.org/soap/envelope/'> \
        <soapenv:Body> \
        <GetListItems xmlns='http://schemas.microsoft.com/sharepoint/soap/'> \
        <listName>Projects</listName> \
        <viewFields> \
        <ViewFields> \
        <FieldRef Name='Title' /> \
        <FieldRef Name='Body' /> \
        <FieldRef Name='ID' /> \
        <FieldRef Name='Attachments' /> \
        </ViewFields> \
        </viewFields> \
        <query> \
        <Query /> \
        </query> \
        <queryOptions> \
        <QueryOptions> \
        <IncludeAttachmentUrls>TRUE</IncludeAttachmentUrls> \
        </QueryOptions> \
        </queryOptions> \
        </GetListItems> \
        </soapenv:Body> \
        </soapenv:Envelope>";

        $.ajax({
            async: false,
            url: "http://server.name.com/site/_vti_bin/lists.asmx",
            type: "POST",
            dataType: "xml",
            data: soapEnv,
            complete: processResult,
            contentType: "text/xml; charset=\"utf-8\""
            });
};
function processResult(xData, status) {
    $(xData.responseXML).find("z\\:row").each(function() {
        if ($(this).attr("ows_Attachments") != 0) {
        var url = $(this).attr("ows_Attachments").replace(/#/g, "").split(';');
        var ID = $(this).attr("ows_ID");
        $("table.ms-listviewtable tr:has(td.ms-vb2)").find("td:first").filter(function() {
            return $(this).text().toLowerCase() == ID;
            }).html("<img src='" + url[1] + "' width=150 height=100 />");
        };
    });
};

Or you can use REST (as the title of your question suggest):

http://YourSharePoint/SubWeb/_api/Web/Lists/GetByTitle('YourList')/Items/?$expand=AttachmentFiles

Instead of CAML, add the condition, ordering and row limit attributes of your query via $filter, $orderby and $top to the REST query as described here.