Display if change has attachment(s) in CAB workbench

[Michael Laban]

We have a request to indicator if attachments exist on a change request that is being displayed at CAB utilizing CAB Workbench.  Currently, CAB Workbench has no indicator if attachments exist.  After searching for like solutions and opening a case with ServiceNow, it appears CAB Workbench is a portal will not use code like the Platform/Legacy UI.  

For example, I have tried:

var chg_id = g_form.getUniqueValue();

var chg_attach_cnt = new GlideRecord("sys_attachment");

chg_attach_cnt.addQuery("table_name", "change_request");

chg_attach_cnt.addQuery("table_sys_id", chg_id);

chg_attach_cnt.query();

var attachment_count = 0;

while (chg_attach_cnt.next()){

    attachment_count++;

}

I have validated that g_form.getUniqueValue(); does return the sys_id of the change request being displayed.  Note:  

g_form.getUniqueValue() and g_form.getSysID() do NOT work in this instance.  

If I use the code above in legacy view the number of attachments is counted and displays just fine.  However in CAB Workbench no value is returned.  

I have also tried creating a custom field on the change_request table with a calculated value.  That also does not work and returns no value in CAB Workbench ... once again, it works in the platform.  

Through searching forums and the Google searches I have not come across any other solution.  

Has anyone been able to achieve an indicator that a change request has an attachment within CAB Workbench?  If so, how?  

Thank you in advance.

[Michael Laban · Accepted solution]

ServiceNow provided this solution-

function onLoad() {
    var chg_id = g_form.getUniqueValue();                       
    var gr = new GlideRecord("sys_attachment");
    gr.addQuery("table_name", "change_request");
    gr.addQuery("table_sys_id", chg_id);
    gr.query(function(response){
        if (response.next()){
            g_form.showFieldMsg('number', "Has attachment(s)", "info", false);
        }
    });
}

With the additional detail of:
1 - We discourage GlideRecord on the client in favour of REST and or the scratchpad on the server side.
2 - The GlideRecord code only work in UI16 because it's forgiving, as we can see the warning in console:
***WARNING *** GlideAjax.getXMLWait - synchronous function - processor: AJAXGlideRecord
*** WARNING *** GlideRecord synchronous query for table: sys_attachment
3 - Service Portal does not support synchronous ajax calls, so the call was never made.

We've refactored you code to support both UI16 and SP, but we highly suggest using a better method and not clientside GlideRecord.