Debounced Search with GlideAjax

// Global variable to store timeout (outside function)
var searchTimeout;

function onChange(control, oldValue, newValue, isLoading, isTemplate) {
  // Exit if form is loading
  if (isLoading) {
    return;
  }

  // Configuration
  var debounceDelay = 500;  // Wait 500ms after user stops typing
  var minSearchLength = 3;   // Minimum characters before searching
  var resultsField = 'u_search_results';  // Field to display results

  // Clear any existing timeout
  if (searchTimeout) {
    clearTimeout(searchTimeout);
  }

  // Clear results if search is too short
  if (!newValue || newValue.length < minSearchLength) {
    g_form.clearValue(resultsField);
    g_form.hideFieldMsg(resultsField);
    return;
  }

  // Show searching indicator
  g_form.showFieldMsg(resultsField, 'Searching...', 'info', false);

  // Set new timeout to execute search after delay
  searchTimeout = setTimeout(function() {
    // Make GlideAjax call to search
    var ga = new GlideAjax('SearchUtils');  // Create corresponding Script Include
    ga.addParam('sysparm_name', 'performSearch');
    ga.addParam('sysparm_search_term', newValue);
    ga.addParam('sysparm_search_table', 'cmdb_ci');  // Table to search
    ga.addParam('sysparm_search_fields', 'name,serial_number');  // Fields to search

    ga.getXMLAnswer(function(response) {
      if (response) {
        try {
          var results = JSON.parse(response);

          // Clear previous message
          g_form.hideFieldMsg(resultsField);

          if (results.count > 0) {
            // Display results count
            var message = 'Found ' + results.count + ' matching record(s)';
            g_form.showFieldMsg(resultsField, message, 'info');

            // Optionally populate a reference field with first result
            if (results.records && results.records.length > 0) {
              var firstResult = results.records[0];
              // g_form.setValue('u_related_ci', firstResult.sys_id);
            }

            // Store results in hidden field or display in custom way
            g_form.setValue(resultsField, JSON.stringify(results.records));
          } else {
            g_form.showFieldMsg(resultsField, 'No matching records found', 'warning');
            g_form.clearValue(resultsField);
          }
        } catch (e) {
          g_form.showFieldMsg(resultsField, 'Error parsing search results', 'error');
          console.error('Search error:', e);
        }
      } else {
        g_form.showFieldMsg(resultsField, 'Search failed - no response', 'error');
      }
    });
  }, debounceDelay);
}