我创建了一个芝加哥员工搜索索引，并希望在找不到匹配的记录时创建一个警报，但似乎无法找出当它为空时需要输入的值。理想情况下，当函数get被提交并且没有找到结果时，它会将警报推送到屏幕上，表明找不到匹配的记录。
现在的提醒位于发布的最后一位代码中的提交功能
ChicagoEmployeesQuery = function(searchKey) {
var url,
url =
"https://data.cityofchicago.org/api/views/xzkq-xp2w/rows.json" +
"?search=key_word&jsonp=?";
this.query = url.replace("key_word", searchKey);
}
ChicagoEmployeesQuery.prototype.getList = function(callBack) {
$.getJSON(this.query, function(response) {
var i, results;
results = [];
for (i = 0; i < response.data.length; i += 1) {
row = {
name: response.data[i][8],
title: response.data[i][9],
department: response.data[i][10],
salary: response.data[i][14]
}
results.push(row);
}
callBack(results);
})
}<!doctype html>
<html>
<head>
<title>Salary Info Demo</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="ChicagoEmployees.js"></script>
<script src="demoLS.js"></script>
</head>
<body>
<h1>Salary Info</h1>
<p>Enter first or last name: <input type="text" id="key-word" size="20" /></p>
<p><input type="button" id="start" value="Submit Query for name and Salary" /></p>
<p><input type="button" id="start2" value="Submit Query for Names and Departments" </p>
<h2>First Matching Employing + Salary</h2>
<div id="result">
First result appears here
</div>
<h2>List of All Matching Names</h2>
<div id="names">
All Matching Names Appear Here
</div>
<h2>List of All Matching Names + Departments</h2>
<div id="namesDepartment">
All Matching Names + Departments Appear Here
</div>
</body>
</html>
// Use with demo.html
// Tested with jQuery 3.1.1, January 2017
// Updated January 2018
// This function is called when the response has returned
postResult = function(list) {
//var nameList, i, glist;
glist = list;
if (list.length > 0) {
$("#result").html(list[0].name + "<br />" + list[0].salary);
}
nameList = "";
for (i = 0; i < list.length; i += 1) {
nameList = nameList + list[i].name + "<br />";
}
$("#names").html(nameList);
}
postResult2 = function(list) {
//var namesDepartmentList, i, glist;
glist = list;
if (list.length > 0) {
$("#namesDepartment").html(list[0].name + "<br />" + list[0].department);
}
namesDepartmentList = "";
for (i = 0; i < list.length; i += 1) {
namesDepartmentList = namesDepartmentList + list[i].name + "<br/>" + list[i].department + "<br />";
}
$("#namesDepartment").html(namesDepartmentList);
}
submit = function() {
var searchWord = document.getElementById("key-word").value;
query = new ChicagoEmployeesQuery(searchWord);
$("#result").html("waiting...");
query.getList(postResult);
if (searchKey.isEmpty()) {
alert("No Matching Records Found");
console.log("A result should appear!");
}
}
submit2 = function() {
var searchWord = document.getElementById("key-word").value;
query = new ChicagoEmployeesQuery(searchWord);
$("#namesDepartment").html("waiting...");
query.getList(postResult2);
console.log("A result should appear now!");
}
$(function() {
$("#start").click(submit);
});
$(function() {
$("#start2").click(submit2);
});
答案 0 :(得分：1)
如果我理解您的问题，您可以检查getlist()
ChicagoEmployeesQuery.prototype.getList = function(callBack) {
$.getJSON(this.query, function(response) {
// ... codes ...
callBack(results);
// like this
if (response.data.length==0) {
alert("No Matching Records Found");
console.log("A result should appear!");
}
})
}
// Use with demo.html
// Tested with jQuery 3.1.1, January 2017
// Updated January 2018
// This function is called when the response has returned
postResult = function(list) {
//var nameList, i, glist;
glist = list;
if (list.length > 0) {
$("#result").html(list[0].name + "<br />" + list[0].salary);
}
nameList = "";
for (i = 0; i < list.length; i += 1) {
nameList = nameList + list[i].name + "<br />";
}
$("#names").html(nameList);
}
postResult2 = function(list) {
//var namesDepartmentList, i, glist;
glist = list;
if (list.length > 0) {
$("#namesDepartment").html(list[0].name + "<br />" + list[0].department);
}
namesDepartmentList = "";
for (i = 0; i < list.length; i += 1) {
namesDepartmentList = namesDepartmentList + list[i].name + "<br/>" + list[i].department + "<br />";
}
$("#namesDepartment").html(namesDepartmentList);
}
submit = function() {
var searchWord = document.getElementById("key-word").value;
query = new ChicagoEmployeesQuery(searchWord);
$("#result").html("waiting...");
query.getList(postResult);
}
submit2 = function() {
var searchWord = document.getElementById("key-word").value;
query = new ChicagoEmployeesQuery(searchWord);
$("#namesDepartment").html("waiting...");
query.getList(postResult2);
console.log("A result should appear now!");
}
$(function() {
$("#start").click(submit);
});
$(function() {
$("#start2").click(submit2);
});
ChicagoEmployeesQuery = function(searchKey) {
var url,
url =
"https://data.cityofchicago.org/api/views/xzkq-xp2w/rows.json" +
"?search=key_word&jsonp=?";
this.query = url.replace("key_word", searchKey);
}
ChicagoEmployeesQuery.prototype.getList = function(callBack) {
$.getJSON(this.query, function(response) {
var i, results;
results = [];
for (i = 0; i < response.data.length; i += 1) {
row = {
name: response.data[i][8],
title: response.data[i][9],
department: response.data[i][10],
salary: response.data[i][14]
}
results.push(row);
}
callBack(results);
if (response.data.length==0) {
alert("No Matching Records Found");
console.log("A result should appear!");
}
})
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h1>Salary Info</h1>
<p>Enter first or last name: <input type="text" id="key-word" size="20" /></p>
<p><input type="button" id="start" value="Submit Query for name and Salary" /></p>
<p><input type="button" id="start2" value="Submit Query for Names and Departments" </p>
<h2>First Matching Employing + Salary</h2>
<div id="result">
First result appears here
</div>
<h2>List of All Matching Names</h2>
<div id="names">
All Matching Names Appear Here
</div>
<h2>List of All Matching Names + Departments</h2>
<div id="namesDepartment">
All Matching Names + Departments Appear Here
</div>