HistoryWalker API is unable to recognise/detect field changes when a field is emptied out!! - Support and Troubleshooting

HistoryWalker API is unable to recognise/detect field changes when a field is emptied out!! Issue 1.Create an incident(You may fill all the Mandatory fields) [sys_mod_count = 0] 2.Fill Assigned To & save [sys_mod_count = 1] 3.Run the below script as a background script:

var hw = new sn_hw.HistoryWalker("incident", ); hw.walkTo(1); var walkedGR = hw.walkForward(); var walkedGr = hw.getWalkedRecord(); var fields = GlideScriptRecordUtil.get(walkedGr).getChangedFieldNames(); gs.print("Fields changed at update " + hw.getUpdateNumber() + " were:"); for (var j = 0; j gs.print(" " + fields.get(j));

Actual: *** Script: Fields changed at update 1 were: *** Script: state *** Script: incident_state *** Script: assigned_to

Expected: *** Script: Fields changed at update 1 were: *** Script: state *** Script: incident_state *** Script: assigned_to

4.Clear Assigned To & save [sys_mod_count = 2] 5.Run the below script as a background script:

var hw = new sn_hw.HistoryWalker("incident", ); hw.walkTo(2); var walkedGR = hw.walkForward(); var walkedGr = hw.getWalkedRecord(); var fields = GlideScriptRecordUtil.get(walkedGr).getChangedFieldNames(); gs.print("Fields changed at update " + hw.getUpdateNumber() + " were:"); for (var j = 0; j gs.print(" " + fields.get(j));

Actual: *** Script: Fields changed at update 2 were:

Expected: *** Script: Fields changed at update 2 were: *** Script: assigned_to

6.Fill Assigned To & save (Like you did in step 3) [sys_mod_count = 3] 7.Fill/Modify description, clear Assigned To & Save [sys_mod_count = 4] 8.Run the below script as a background script:

var hw = new sn_hw.HistoryWalker("incident", ); hw.walkTo(4); var walkedGR = hw.walkForward(); var walkedGr = hw.getWalkedRecord(); var fields = GlideScriptRecordUtil.get(walkedGr).getChangedFieldNames(); gs.print("Fields changed at update " + hw.getUpdateNumber() + " were:"); for (var j = 0; j gs.print(" " + fields.get(j));

Actual: *** Script: Fields changed at update 4 were: *** Script: description

Expected: *** Script: Fields changed at update 4 were: *** Script: description *** Script: assigned_to

Cause This is the expected behavior. If the element does not have a value it is not returned. Resolution You can try the following as a general work around: var incGr = new GlideRecord('incident'); incGr.get('number', 'INC0025769'); var hw = new sn_hw.HistoryWalker(incGr.getTableName(), incGr.getUniqueValue()); hw.walkTo(0); do { printChangedFields(hw); } while (hw.walkForward()); function printChangedFields(hw) { var updatenumber = hw.getUpdateNumber(); if (updatenumber == 0) { var walkedGr = hw.getWalkedRecord(); var fields = GlideScriptRecordUtil.get(walkedGr).getChangedFieldNames(); gs.print("Fields changed at update " + hw.getUpdateNumber() + " were:"); for (var j = 0; j gs.print(" " + fields.get(j)); gs.print(""); } else { var walkedGr = hw.getWalkedRecord(); fields = new GlideRecordUtil().getFields(walkedGr);

var prevupdatenumber = updatenumber - 1; var hw2 = new sn_hw.HistoryWalker(incGr.getTableName(), incGr.getUniqueValue()); hw2.walkTo(prevupdatenumber);

prevwalkedGr = hw2.getWalkedRecord(); fields2 = new GlideRecordUtil().getFields(prevwalkedGr);

gs.print("Fields changed at update " + hw.getUpdateNumber() + " were:"); for (var j = 0; j if (walkedGr.getValue(fields[j]) != prevwalkedGr.getValue(fields2[j]) && !fields[j].startsWith("sys_") ) gs.print("changed " +fields[j]); } gs.print(""); } }