Get Attachments through REST API

[Aruna Sree Yela]

Hi,

3rd party tool is calling servicenow to get attachments of RITM in binary stream.

I want to achieve this using script include and Scripted REST API. How to achieve this

Thanks

[Tony Chatfield1]

Hi, if your third party app is making a REST call to retrieve the attachment then I would expect it to be a call to the sys_attachment table, and I do not see any reason to need a script-include or scripted rest API as part of the process.

Have you looked at GlideSysAttachment getContentBase64() ?

GlideSysAttachment | ServiceNow Developers

If I have misunderstood? perhaps you could clarify your requirement.

[Aruna Sree Yela]

Hi @Tony Chatfield1 , thank you for the response!

The reason behind using script include is we have multiple APIs for different use where we are calling all of them from a common script include.

Below is the script include function:

getAttachment: function(request) {
var attachmentSysId = request.queryParams.sys_id;
var attachmentGR = new GlideRecord('sys_attachment');
attachmentGR.addQuery('sys_id', attachmentSysId);
attachmentGR.query();
if (attachmentGR.next()) {
                var attachment = new GlideSysAttachment();
                var content = attachment.getBytes(attachmentGR);
                var contentType = attachmentGR.content_type;
                var base64 = GlideStringUtil.base64Encode(content);
                var binaryData = GlideStringUtil.base64Decode(base64);
                gs.log('base64: ' + base64);
                gs.log('binaryData: ' + binaryData);
            }
            return binaryData;
}

Calling that in Scripted REST API

var siUtil = new SI_Utils();
var reqResponse = siUtil.getAttachment(request);
response.setContentType(reqResponse.contentType);
response.getStreamWriter().writeBytes(reqResponse.content);

I'm able to see the base64 and binaryData logs, but rest explorer is showing "". Not getting the binary value. Seems like something is wrong while calling it in Scripted REST API. Could you please correct me where I missed it.

[Ankur Bawiskar]

@Aruna Sree Yela 

what's your business requirement to send binary data?

In ServiceNow attachments are stored with base64 encoding.

You can only get a string that represents binary, but not actual binary object.

If my response helped please mark it correct and close the thread so that it benefits future readers.

[Ankur Bawiskar]

You can only get a string that represents binary, but not actual binary object.

[Aruna Sree Yela]

@Ankur Bawiskar , Got it. Now below is my function from Script Include to get base64 , then how can I call that and set the response body in Scripted REST API - Get method. Because I'm getting the value in logs but in Explorer getting error like

message: "Script Evaluation Exception",

details: "Cannot convert xebywynuemxyzdbednuic4....................."

getAttachment: function(request) {
            var attachmentSysId = request.queryParams.sys_id;
            gs.log("attachmentSysId " + attachmentSysId);

            var attachmentGR = new GlideRecord('sys_attachment');
            attachmentGR.addQuery('sys_id', attachmentSysId);
            attachmentGR.query();
            if (attachmentGR.next()) {
                var attachment = new GlideSysAttachment();

                var bytes = attachment.getBytes(attachmentGR);
                var base64 = GlideStringUtil.base64Encode(bytes);

                gs.log('base64: ' + base64);
            }
            return base64;
}