Question

我使用javascript创建了自动填充表单，该表单以

之类的数组形式获取数据

var city_list = ["Allahabad","Baramulla","Bellary"]

但是我的控制器以json格式（如

）返回请求的数据

[{"city_id": 9,"city_name": "Allahabad"},{"city_id": 47,"city_name": "Baramulla"},{"city_id": 60,"city_name": "Bellary"}]

我搜索了很多StackOverflow和Internet帖子，但对我没有任何帮助，并且由于我不擅长javascript，所以无法自行找到解决方案。

Ajax请求

$('#heroCitySearch').keyup(function () {
     var q = 'q='+$(this).val();
     if(q != '') {
        $.ajax({
           type:'GET',
           url:"/fetch/city",
           data:q,
           success:function (data) {
              if(data){
                 $.each(data,function(value){
                    autocomplete(document.getElementById("heroCitySearch"), data[value].city_name);

                    // "data[value].city_name" <- This parameter must be an array

              }
           }
        })
     }
  });

JavaScript函数（自动完成）

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);

   /*==== Below is the code block which uses array elements====*/

   /*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;
           /*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);
});
}

我已从w3school复制了上述脚本。

在上面的代码b.innerHTML += "<input type='hidden' value='" + arr[i] + "'>";中如果要使用城市ID，请使用城市ID代替。

感谢您的帮助。

Answer 1

下面的示例代码片段将帮助您仅获取城市名称：

<!-- begin snippet: js hide: false console: true babel: false -->

<!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" 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;
              /*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 = [{"city_id": 9,"city_name": "Allahabad"},{"city_id": 47,"city_name": "Baramulla"},{"city_id": 60,"city_name": "Bellary"}].map(city => city.city_name);

/*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>

const cityArry = [{"city_id": 9,"city_name": "Allahabad"},{"city_id": 47,"city_name": "Baramulla"},{"city_id": 60,"city_name": "Bellary"}]

console.log(cityArry.map(city => city.city_name))

Answer 2

您可以从JSON响应中提取所需的内容。像这样：

// You example
var cities = [{
  "city_id": 9,
  "city_name": "Allahabad"
}, {
  "city_id": 47,
  "city_name": "Baramulla"
}, {
  "city_id": 60,
  "city_name": "Bellary"
}];

const myFormat = cities.map((city) => {
  return city.city_name;
})

console.log(myFormat);
// Output
// [
//   "Allahabad",
//   "Baramulla",
//   "Bellary"
// ]

Answer 3

代替此：

if (arr[i].substr(0, val.length).toUpperCase() == val.toUpperCase()) {

}

使用此：

if (arr[i].city_id == +val ||
    arr[i].city_name.substr(0, val.length).toUpperCase() == val.toUpperCase()) {
}

+val会将值转换为数字。

，您还可以通过添加正则表达式匹配项来改善搜索效果，这样它将在名称中的任意位置找到文本

var re = new RegExp(val, 'i');

if (arr[i].city_id == +val || re.test(arr[i].city_name)) {

}

如果要在输入中使用*或+之类的特殊字符，则需要escape the regex special characters。

如何在JavaScript函数中将来自ajax请求的json响应用作Javascript数组

3 个答案: