英文:
Use specific select option when loading the page (jQuery + Ajax)
问题
我使用jQuery + Ajax检索URL并根据某些选择选项确定显示。选择工作正常，但我无法设置默认值。我希望value="3"被预先选择，并在加载页面时显示相应的结果，而无需先选择选项。我该怎么做？
以下是迄今为止的我的代码：
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!DOCTYPE html>
<html>
<body>
<form>
<select id="reportMonth" name="reportMonth">
<option value="">选择：</option>
<option value="0">1</option>
<option value="1">2</option>
<option value="2">3</option>
<option value="3">4</option>
</select>
</form>
<div id="show_output"></div>
</body>
</html>
$(document).ready(function() {
$("#reportMonth").on('change', function() {
var reportMonth = $('#reportMonth :selected').val();
if(reportMonth){
$.ajax({
type: "GET",
url: "https://api.tools.paeddy.de/server_info",
dataType: "json",
timeout: 15000,
})
.done(function(JSONOut) {
var out = "服务器 " + JSONOut[reportMonth].server + " = " + JSONOut[reportMonth].status;
$('#output').html(out);
})
.fail(function(xhr, status, error) {
$('#output').html('<div class="error">错误：' + xhr.status + ' - ' + error + '</div>');
});
$('#show_output').html('<div id="output"></div>');
}
});
});
英文:
I retrieve a URL with jQuery + Ajax and determine the display based on certain select options.
The selection works fine, however I can't manage to place a default. I would like value="3" to be preselected and show the corresponding result already when loading the page, without having selected an option before.
How can I do this?
Here is my code so far:
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-html -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!DOCTYPE html>
<html>
<body>
<form>
<select id="reportMonth" name="reportMonth">
<option value="">Select:</option>
<option value="0">1</option>
<option value="1">2</option>
<option value="2">3</option>
<option value="3">4</option>
</select>
</form>
<div id="show_output"></div>
</body>
</html>
<!-- language: lang-js -->
$(document).ready(function() {
$("#reportMonth").on('change', function() {
var reportMonth = $('#reportMonth :selected').val();
if(reportMonth){
$.ajax({
type: "GET",
url: "https://api.tools.paeddy.de/server_info",
dataType: "json",
timeout: 15000,
})
.done(function(JSONOut) {
var out = "Server " + JSONOut[reportMonth].server + " = " + JSONOut[reportMonth].status;
$('#output').html(out);
})
.fail(function(xhr, status, error) {
$('#output').html("<div class='error'>Error: " + xhr.status + ' - ' + error + "</div>");
});
$('#show_output').html('<div id="output"></div>');
}
});
});
<!-- end snippet -->
答案1
得分: 2
看起来你正在寻找selected属性。你还需要运行AJAX代码来获取默认值的结果，所以将你的onchange处理程序提取到一个函数中，然后在onready处理程序内调用它。就像这样：
function getResult() {
var reportMonth = $('#reportMonth :selected').val();
if (reportMonth) {
$.ajax({
type: "GET",
url: "https://api.tools.paeddy.de/server_info",
dataType: "json",
timeout: 15000,
})
.done(function(JSONOut) {
var out = "Server " + JSONOut[reportMonth].server + " = " + JSONOut[reportMonth].status;
$('#output').html(out);
})
.fail(function(xhr, status, error) {
$('#output').html('<div class="error">Error: ' + xhr.status + ' - ' + error + '</div>');
});
$('#show_output').html('<div id="output"></div>');
}
}
$(document).ready(function() {
getResult();
$("#reportMonth").on('change', getResult);
});
<!DOCTYPE html>
<html>
<body>
<form>
<select id="reportMonth" name="reportMonth">
<option value="">Select:</option>
<option value="0">1</option>
<option value="1">2</option>
<option value="2">3</option>
<option value="3" selected>4</option>
</select>
</form>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="show_output"></div>
</body>
</html>
英文:
It looks like you're looking for the selected attribute. You'll also need to run the AJAX code to fetch the result for the default value, so extract your onchange handler into a function, then call it inside the onready handler. Like this:
<!-- begin snippet: js hide: false console: true babel: false -->
<!-- language: lang-js -->
function getResult() {
var reportMonth = $('#reportMonth :selected').val();
if (reportMonth) {
$.ajax({
type: "GET",
url: "https://api.tools.paeddy.de/server_info",
dataType: "json",
timeout: 15000,
})
.done(function(JSONOut) {
var out = "Server " + JSONOut[reportMonth].server + " = " + JSONOut[reportMonth].status;
$('#output').html(out);
})
.fail(function(xhr, status, error) {
$('#output').html("<div class='error'>Error: " + xhr.status + ' - ' + error + "</div>");
});
$('#show_output').html('<div id="output"></div>');
}
}
$(document).ready(function() {
getResult();
$("#reportMonth").on('change', getResult);
});
<!-- language: lang-html -->
<!DOCTYPE html>
<html>
<body>
<form>
<select id="reportMonth" name="reportMonth">
<option value="">Select:</option>
<option value="0">1</option>
<option value="1">2</option>
<option value="2">3</option>
<option value="3" selected>4</option>
</select>
</form>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="show_output"></div>
</body>
</html>
<!-- end snippet -->
答案2
得分: 0
只是一些超时和调用 触发更改。
$(document).ready(function() {
setTimeout(function() {
$("#reportMonth").trigger('change');
});
$("#reportMonth").on('change', function() {
var reportMonth = $('#reportMonth :selected').val();
if(reportMonth){
$.ajax({
type: "GET",
url: "https://api.tools.paeddy.de/server_info",
dataType: "json",
timeout: 15000,
})
.done(function(JSONOut) {
var out = "Server " + JSONOut[reportMonth].server + " = " + JSONOut[reportMonth].status;
$('#output').html(out);
})
.fail(function(xhr, status, error) {
$('#output').html('<div class="error">Error: ' + xhr.status + ' - ' + error + '</div>');
});
$('#show_output').html('<div id="output"></div>');
}
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!DOCTYPE html>
<html>
<body>
<form>
<select id="reportMonth" name="reportMonth">
<option value="">Select:</option>
<option value="0">1</option>
<option value="1">2</option>
<option value="2">3</option>
<option value="3" selected="selected">4</option>
</select>
</form>
<div id="show_output"></div>
</body>
</html>
英文:
Just and some timeout and call trigger change.
<!-- begin snippet: js hide: false console: true babel: null -->
<!-- language: lang-js -->
$(document).ready(function() {
setTimeout(function() {
$("#reportMonth").trigger('change');
});
$("#reportMonth").on('change', function() {
var reportMonth = $('#reportMonth :selected').val();
if(reportMonth){
$.ajax({
type: "GET",
url: "https://api.tools.paeddy.de/server_info",
dataType: "json",
timeout: 15000,
})
.done(function(JSONOut) {
var out = "Server " + JSONOut[reportMonth].server + " = " + JSONOut[reportMonth].status;
$('#output').html(out);
})
.fail(function(xhr, status, error) {
$('#output').html("<div class='error'>Error: " + xhr.status + ' - ' + error + "</div>");
});
$('#show_output').html('<div id="output"></div>');
}
});
});
<!-- language: lang-html -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!DOCTYPE html>
<html>
<body>
<form>
<select id="reportMonth" name="reportMonth">
<option value="">Select:</option>
<option value="0">1</option>
<option value="1">2</option>
<option value="2">3</option>
<option value="3" selected="selected">4</option>
</select>
</form>
<div id="show_output"></div>
</body>
</html>
<!-- end snippet -->
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