从自动完成列表中提交查询而无需点击提交按钮

Submitting query from the autocomplete list without having to hit the submit button

我尝试采用 W3Schools 中关于自动完成的示例,并将自动完成(建议)列表中的值从列表中放入输入的文本区域,并自动提交,这无需点击发送按钮。我们看到了这一点以及几乎所有主要的搜索引擎。你开始输入你的查询,建议框会掉下来,你选择你的词,它会自动被放入输入框的文本区域,然后被提交,你不必按提交。我相信我缺少一个函数,或者这里有另一段代码:

b.addEventListener("click", function(e) {
                                                                /*insert the value for the autocomplete text field:*/
                                                                inp.value = this.getElementsByTagName("input")[0].value;
                                                                /*close the list of autocompleted values,
                                                                 (or any other open lists of autocompleted values:*/
                                                                closeAllLists();
                                                                });
                                             a.appendChild(b);

我已经研究了这个问题,以及可能的解决方案,例如添加 e.submit(),或者我添加的地方

b.addEventListener("submit", function(e) {
                                                                                 if ("search_form_input_homepage").val() !== '') {
                                                            e.submit();

下面的函数(我也将 preventDefault 更改为 e.submit)

                        function autocomplete(inp, arr) {
                        /*the autocomplete function takes two arguments,
                         the text field element and an array of possible autocompleted values:*/
                        var currentFocus;
                        /*execute a function when someone writes in the text field:*/
                        inp.addEventListener("input", function(e) {
                                             var a, b, i, val = this.value;
                                             /*close any already open lists of autocompleted values*/
                                             closeAllLists();
                                             if (!val) { return false;}
                                             currentFocus = -1;
                                             /*create a DIV element that will contain the items (values):*/
                                             a = document.createElement("DIV");
                                             a.setAttribute("id", this.id + "autocomplete-list");
                                             a.setAttribute("class", "autocomplete-items");
                                             /*append the DIV element as a child of the autocomplete container:*/
                                             this.parentNode.appendChild(a);
                                             /*for each item in the array...*/
                                             for (i = 0; i < arr.length; i++) {
                                             /*check if the item starts with the same letters as the text field value:*/
                                             if (arr[i].substr(0, val.length).toUpperCase() == val.toUpperCase()) {
                                             /*create a DIV element for each matching element:*/
                                             b = document.createElement("DIV");
                                             /*make the matching letters bold:*/
                                             b.innerHTML = "<strong>" + arr[i].substr(0, val.length) + "</strong>";
                                             b.innerHTML += arr[i].substr(val.length);
                                             /*insert a input field that will hold the current array item's value:*/
                                             b.innerHTML += "<input type='hidden' value='" + arr[i] + "'>";
                                             /*execute a function when someone clicks on the item value (DIV element):*/
                                             b.addEventListener("click", function(e) {
                                                                /*insert the value for the autocomplete text field:*/
                                                                inp.value = this.getElementsByTagName("input")[0].value;
                                                                (e).submit();
                                                                /*close the list of autocompleted values,
                                                                 (or any other open lists of autocompleted values:*/
                                                                closeAllLists();
                                                                /*and simulate a click on the "active" item:*/

                                                                b.addEventListener("submit", function(e) {
                                                                                     if ("search_form_input_homepage").val() !== '') {
                                                                e.submit();
                                                                }
                                                                };
                                                                })
                                             ;
                                             a.appendChild(b);
                                             }
                                             }
                                             });
                                             /*execute a function presses a key on the keyboard:*/
                                             inp.addEventListener("keydown", function(e) {
                                                                  var x = document.getElementById(this.id + "autocomplete-list");
                                                                  if (x) x = x.getElementsByTagName("div");
                                                                  if (e.keyCode == 40) {
                                                                  /*If the arrow DOWN key is pressed,
                                                                   increase the currentFocus variable:*/
                                                                  currentFocus++;
                                                                  /*and and make the current item more visible:*/
                                                                  addActive(x);
                                                                  } else if (e.keyCode == 38) { //up
                                                                  /*If the arrow UP key is pressed,
                                                                   decrease the currentFocus variable:*/
                                                                  currentFocus--;
                                                                  /*and and make the current item more visible:*/
                                                                  addActive(x);
                                                                  } else if (e.keyCode == 13) {
                                                                  /*If the ENTER key is pressed, allow the form to be submitted,*/
                                                                  e.submit();
                                                                  if (currentFocus > -1) {
                                                                  /*and simulate a click on the "active" item:*/
                                                                  if (x) x[currentFocus].click();
                                                                  }
                                                                  }
                                                                  });
                                                                  function addActive(x) {
                                                                      /*a function to classify an item as "active":*/
                                                                      if (!x) return false;
                                                                      /*start by removing the "active" class on all items:*/
                                                                      removeActive(x);
                                                                      if (currentFocus >= x.length) currentFocus = 0;
                                                                      if (currentFocus < 0) currentFocus = (x.length - 1);
                                                                      /*add class "autocomplete-active":*/
                                                                      x[currentFocus].classList.add("autocomplete-active");
                                                                  }
                                                                  function removeActive(x) {
                                                                      /*a function to remove the "active" class from all autocomplete items:*/
                                                                      for (var i = 0; i < x.length; i++) {
                                                                          x[i].classList.remove("autocomplete-active");
                                                                      }
                                                                  }
                                                                  function closeAllLists(elmnt) {
                                                                      /*close all autocomplete lists in the document,
                                                                       except the one passed as an argument:*/
                                                                      var x = document.getElementsByClassName("autocomplete-items");
                                                                      for (var i = 0; i < x.length; i++) {
                                                                          if (elmnt != x[i] && elmnt != inp) {
                                                                              x[i].parentNode.removeChild(x[i]);
                                                                          }
                                                                      }
                                                                  }
                                                                  /*execute a function when someone clicks in the document:*/
                                                                  document.addEventListener("click", function (e) {
                                                                                 …

我在这里做了什么:

  1. 给表单一个 ID 例如 myForm

  2. (e).submit();替换为 document.getElementById("myForm").submit();

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
* {
  box-sizing: border-box;
}

body {
  font: 16px Arial;  
}

.autocomplete {
  /*the container must be positioned relative:*/
  position: relative;
  display: inline-block;
}

input {
  border: 1px solid transparent;
  background-color: #f1f1f1;
  padding: 10px;
  font-size: 16px;
}

input[type=text] {
  background-color: #f1f1f1;
  width: 100%;
}

input[type=submit] {
  background-color: DodgerBlue;
  color: #fff;
  cursor: pointer;
}

.autocomplete-items {
  position: absolute;
  border: 1px solid #d4d4d4;
  border-bottom: none;
  border-top: none;
  z-index: 99;
  /*position the autocomplete items to be the same width as the container:*/
  top: 100%;
  left: 0;
  right: 0;
}

.autocomplete-items div {
  padding: 10px;
  cursor: pointer;
  background-color: #fff; 
  border-bottom: 1px solid #d4d4d4; 
}

.autocomplete-items div:hover {
  /*when hovering an item:*/
  background-color: #e9e9e9; 
}

.autocomplete-active {
  /*when navigating through the items using the arrow keys:*/
  background-color: DodgerBlue !important; 
  color: #ffffff; 
}
</style>
</head>     

<body>

<h2>Autocomplete</h2>

<p>Start typing:</p>

<!--Make sure the form has the autocomplete function switched off:-->
<form autocomplete="off" id="myForm" action="/action_page.php">
  <div class="autocomplete" style="width:300px;">
    <input id="myInput" type="text" name="myCountry" placeholder="Country">
  </div>
  <input type="submit">
</form>

<script>
function autocomplete(inp, arr) {
  /*the autocomplete function takes two arguments,
  the text field element and an array of possible autocompleted values:*/
  var currentFocus;
  /*execute a function when someone writes in the text field:*/
  inp.addEventListener("input", function(e) {
      var a, b, i, val = this.value;
      /*close any already open lists of autocompleted values*/
      closeAllLists();
      if (!val) { return false;}
      currentFocus = -1;
      /*create a DIV element that will contain the items (values):*/
      a = document.createElement("DIV");
      a.setAttribute("id", this.id + "autocomplete-list");
      a.setAttribute("class", "autocomplete-items");
      /*append the DIV element as a child of the autocomplete container:*/
      this.parentNode.appendChild(a);
      /*for each item in the array...*/
      for (i = 0; i < arr.length; i++) {
        /*check if the item starts with the same letters as the text field value:*/
        if (arr[i].substr(0, val.length).toUpperCase() == val.toUpperCase()) {
          /*create a DIV element for each matching element:*/
          b = document.createElement("DIV");
          /*make the matching letters bold:*/
          b.innerHTML = "<strong>" + arr[i].substr(0, val.length) + "</strong>";
          b.innerHTML += arr[i].substr(val.length);
          /*insert a input field that will hold the current array item's value:*/
          b.innerHTML += "<input type='hidden' value='" + arr[i] + "'>";
          /*execute a function when someone clicks on the item value (DIV element):*/
          b.addEventListener("click", function(e) {
              /*insert the value for the autocomplete text field:*/
              inp.value = this.getElementsByTagName("input")[0].value;
              document.getElementById("myForm").submit();
              /*close the list of autocompleted values,
              (or any other open lists of autocompleted values:*/
              closeAllLists();
          });
          a.appendChild(b);
        }
      }
  });
  /*execute a function presses a key on the keyboard:*/
  inp.addEventListener("keydown", function(e) {
      var x = document.getElementById(this.id + "autocomplete-list");
      if (x) x = x.getElementsByTagName("div");
      if (e.keyCode == 40) {
        /*If the arrow DOWN key is pressed,
        increase the currentFocus variable:*/
        currentFocus++;
        /*and and make the current item more visible:*/
        addActive(x);
      } else if (e.keyCode == 38) { //up
        /*If the arrow UP key is pressed,
        decrease the currentFocus variable:*/
        currentFocus--;
        /*and and make the current item more visible:*/
        addActive(x);
      } else if (e.keyCode == 13) {
        /*If the ENTER key is pressed, prevent the form from being submitted,*/
        e.preventDefault();
        if (currentFocus > -1) {
          /*and simulate a click on the "active" item:*/
          if (x) x[currentFocus].click();
        }
      }
  });
  function addActive(x) {
    /*a function to classify an item as "active":*/
    if (!x) return false;
    /*start by removing the "active" class on all items:*/
    removeActive(x);
    if (currentFocus >= x.length) currentFocus = 0;
    if (currentFocus < 0) currentFocus = (x.length - 1);
    /*add class "autocomplete-active":*/
    x[currentFocus].classList.add("autocomplete-active");
  }
  function removeActive(x) {
    /*a function to remove the "active" class from all autocomplete items:*/
    for (var i = 0; i < x.length; i++) {
      x[i].classList.remove("autocomplete-active");
    }
  }
  function closeAllLists(elmnt) {
    /*close all autocomplete lists in the document,
    except the one passed as an argument:*/
    var x = document.getElementsByClassName("autocomplete-items");
    for (var i = 0; i < x.length; i++) {
      if (elmnt != x[i] && elmnt != inp) {
        x[i].parentNode.removeChild(x[i]);
      }
    }
  }
  /*execute a function when someone clicks in the document:*/
  document.addEventListener("click", function (e) {
      closeAllLists(e.target);
  });
}

/*An array containing all the country names in the world:*/
var countries = ["Afghanistan","Albania","Algeria","Andorra","Angola","Anguilla","Antigua & Barbuda","Argentina","Armenia","Aruba","Australia","Austria","Azerbaijan","Bahamas","Bahrain","Bangladesh","Barbados","Belarus","Belgium","Belize","Benin","Bermuda","Bhutan","Bolivia","Bosnia & Herzegovina","Botswana","Brazil","British Virgin Islands","Brunei","Bulgaria","Burkina Faso","Burundi","Cambodia","Cameroon","Canada","Cape Verde","Cayman Islands","Central Arfrican Republic","Chad","Chile","China","Colombia","Congo","Cook Islands","Costa Rica","Cote D Ivoire","Croatia","Cuba","Curacao","Cyprus","Czech Republic","Denmark","Djibouti","Dominica","Dominican Republic","Ecuador","Egypt","El Salvador","Equatorial Guinea","Eritrea","Estonia","Ethiopia","Falkland Islands","Faroe Islands","Fiji","Finland","France","French Polynesia","French West Indies","Gabon","Gambia","Georgia","Germany","Ghana","Gibraltar","Greece","Greenland","Grenada","Guam","Guatemala","Guernsey","Guinea","Guinea Bissau","Guyana","Haiti","Honduras","Hong Kong","Hungary","Iceland","India","Indonesia","Iran","Iraq","Ireland","Isle of Man","Israel","Italy","Jamaica","Japan","Jersey","Jordan","Kazakhstan","Kenya","Kiribati","Kosovo","Kuwait","Kyrgyzstan","Laos","Latvia","Lebanon","Lesotho","Liberia","Libya","Liechtenstein","Lithuania","Luxembourg","Macau","Macedonia","Madagascar","Malawi","Malaysia","Maldives","Mali","Malta","Marshall Islands","Mauritania","Mauritius","Mexico","Micronesia","Moldova","Monaco","Mongolia","Montenegro","Montserrat","Morocco","Mozambique","Myanmar","Namibia","Nauro","Nepal","Netherlands","Netherlands Antilles","New Caledonia","New Zealand","Nicaragua","Niger","Nigeria","North Korea","Norway","Oman","Pakistan","Palau","Palestine","Panama","Papua New Guinea","Paraguay","Peru","Philippines","Poland","Portugal","Puerto Rico","Qatar","Reunion","Romania","Russia","Rwanda","Saint Pierre & Miquelon","Samoa","San Marino","Sao Tome and Principe","Saudi Arabia","Senegal","Serbia","Seychelles","Sierra Leone","Singapore","Slovakia","Slovenia","Solomon Islands","Somalia","South Africa","South Korea","South Sudan","Spain","Sri Lanka","St Kitts & Nevis","St Lucia","St Vincent","Sudan","Suriname","Swaziland","Sweden","Switzerland","Syria","Taiwan","Tajikistan","Tanzania","Thailand","Timor L'Este","Togo","Tonga","Trinidad & Tobago","Tunisia","Turkey","Turkmenistan","Turks & Caicos","Tuvalu","Uganda","Ukraine","United Arab Emirates","United Kingdom","United States of America","Uruguay","Uzbekistan","Vanuatu","Vatican City","Venezuela","Vietnam","Virgin Islands (US)","Yemen","Zambia","Zimbabwe"];

/*initiate the autocomplete function on the "myInput" element, and pass along the countries array as possible autocomplete values:*/
autocomplete(document.getElementById("myInput"), countries);
</script>

</body>
</html>