Hi @arshad199110 

Here are a couple of approaches from mine that you can consider to auto-populate fields when opening the com.glideapp.servicecatalog_cat_item_view UI page.

1. Define an OnLoad client script within the catalog item. Then retrieve the URI and extract the record sys_id to set the variable value accordingly

function onLoad() {
	var uri = top.location.href;
	var recordId = '';
	if(uri.indexOf('demand.do') >= 0){ //replace the table name
		var indexSysId = uri.indexOf('sys_id=') + 7;
		recordId = uri.substring(indexSysId, indexSysId+32);
	}

	if(recordId !== ''){
		g_form.setValue('ticket', recordId); //your ticket reference catalog variable
	}
}

2. We customize the UI Page. Clone the UI page and modify it as follows:

HTML

<input type="hidden" id="task_sys_id" name="task_sys_id" value="${sysparm_task_id}"/>

Client Script

addLoadEvent(function(){
	var taskId = $('task_sys_id').value;
	g_form.setValue('variables.task', taskId);
});

UI Action

//call your customized UI page here
dialog.addParm('sysparm_task_id', g_form.getUniqueValue());

Cheers,

Tai Vu