<template name="autocomplete">
    <input id="{{name}}" class="autocomplete-input {{className}}"
        placeholder="{{placeholder}}" autocomplete="off"/>
    <ul class="suggestions"></ul>
</template>

(function() {
    var inputEl, suggestionsEl, timeout, displayedSuggestions, selectedSuggestion;
    var search = function(inputString) {
        if (timeout) {
            clearTimeout(timeout);
        }
        timeout = setTimeout(function() {
            HTTP.get("https://photon.komoot.de/api/?q=" + inputString + "&lang=" + globalConfig.language, {},
                function(error, response) {
                    if (error) {

                    } else {
                        displayedSuggestions = response.data.features;
                        display(displayedSuggestions);
                    }
                });
        }, 300);
    };

    var suggestionString = function (suggestion) {
        return suggestion.properties.name + ' (' + suggestion.properties.country + ')';
    };

    var selectSuggestion = function(elt) {
        inputEl.value = elt.innerHTML;
        selectedSuggestion = displayedSuggestions[elt['data-index']];
        suggestionsEl.style.display = 'none';
    };

    var display = function(data) {
        suggestionsEl.innerHTML = '';
        suggestionsEl.style.display = 'block';
        for (var i = 0; i < data.length; i++) {
            var suggestion = data[i];
            var li = document.createElement('li');
            li.className = "suggestion";
            li.onclick = function() {selectSuggestion(this);};
            li['data-index'] = i;
            li.innerHTML = suggestionString(suggestion);
            suggestionsEl.appendChild(li);
        }

    };

    Template.autocomplete.onRendered( function(){
        inputEl = this.find('.autocomplete-input');
        suggestionsEl = this.find('.suggestions');
    });

    Template.autocomplete.events({
        "keyup .autocomplete-input": function (event) {
            search(event.target.value);
        }
    });
})();

function(error, response) {
  if (error) {

  } else {
    displayedSuggestions = response.data.features;
    display(displayedSuggestions);
  }
}

// to

function(error, response){
  if(error) return; // throw new Error('nothing') or console.warn('')
  displayedSuggestions = response.data.features;
  display(displayedSuggestions);
}

function debounce(fn, delay){
  var timer = null;
  return function(){
    if(timer) clearTimeout(timer);
    setTimeout(fn, delay || 300);
  }
}

var search = debounce(function(){
  // Your AJAX code
});