試圖使用敲除JavaScript來獲得自動完成工作

Question

我正在嘗試使用Knockout實現自動完成，該自動完成示例取自： https : //www.w3schools.com/howto/howto_js_autocomplete.asp

我正在嘗試將所有JavaScript /淘汰賽保存在單獨的文件中，這是到目前為止在淘汰賽文件中的樣子：

var ViewModel = function () {
var self = this;

this.counties = ko.observableArray([]);

this.getCounties = function () {
    self.counties([]);
    $.ajax({
        url: '/Search/ByCounty',
        type: 'GET',
        success: function (data) {
            if (data && data.length > 0) {
                for (var i = 0; i < data.length; i++) {
                    var obj = data[i];
                    self.counties.push(obj);
                }
            }
        },
        error: function (error) {
            console.log(error);
        }
    });
};

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);
    });
}

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

};

ko.applyBindings(new ViewModel());

上面使用我使用getCounties函數調用的ajax調用是可以的，因為這會帶回我的json並將其放入數組中。 但是，這些值然后不會出現在我看來的自動完成輸入中，也沒有錯誤。 我認為html是在單獨的頁面上，如下所示：

<div style="margin-top:10px;" class="row">
    <div class="col">
        <form autocomplete="off">
            <div class="autocomplete" style="width:300px;">
                <input id="myInput" type="text" name="myCounty" placeholder="County">
            </div>
            <button type="button" class="btn btn-primary" onclick="search('county')">Go</button>
        </form>
    </div>
</div>

我猜想我的淘汰賽文件中的這一行肯定不正確嗎？...或者我的綁定在某處關閉了？..

autocomplete(document.getElementById("myInput"), self.counties());

Answer 1

兩個小錯誤：

1. 僅在ajax調用完成后才應調用autocomplete函數。 否則self.counties()仍為空。
2. 您從未調用過this.Counties() 。 因此，我在以前稱為autocomplete的位置調用了它。

 var ViewModel = function () { var self = this; this.counties = ko.observableArray([]); this.getCounties = function () { self.counties([]); $.ajax({ url: '/Search/ByCounty', type: 'GET', success: function (data) { if (data && data.length > 0) { for (var i = 0; i < data.length; i++) { var obj = data[i]; self.counties.push(obj); } } autocomplete(document.getElementById("myInput"), self.counties()); }, error: function (error) { console.log(error); } }); }; function autocomplete(inp, arr) { ... }); function addActive(x) { ... } function removeActive(x) { ... } function closeAllLists(elmnt) { ... } /*execute a function when someone clicks in the document:*/ document.addEventListener("click", function (e) { closeAllLists(e.target); }); } /*initiate the autocomplete function on the "myInput" element, and pass along the countries array as possible autocomplete values:*/ this.getCounties(); }; ko.applyBindings(new ViewModel()); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-min.js"></script> <div style="margin-top:10px;" class="row"> <div class="col"> <form autocomplete="off"> <div class="autocomplete" style="width:300px;"> <input id="myInput" type="text" name="myCounty" placeholder="County"> </div> <button type="button" class="btn btn-primary" onclick="search('county')">Go</button> </form> </div> </div>