javascript - 选择更改时的 JS 更改表单操作不适用于 .trim()

Question

我有一个表单，当用户从<select></select>中选择一个选项时，我想更改其操作。下拉菜单。

这是我的表格:

    <form role="form"  method="post" id="switch-customer-form" class="switch-customer-form">
        {% csrf_token %}
        <div class="form-group col-xs-12 floating-label-form-group controls">
            <select class="form-control customers-dropdown" id="customers-dropdown" name="form_customers">
                {% for c in customers %}
                    <option{% if customer == c %} selected="true"{% endif %}>{{ c }} - {{ c.id }}</option>
                {% endfor %}
            </select> 
        </div>
        <div class="form-group col-xs-12 floating-label-form-group controls">
            <input type="submit" value="View Calendar" class="btn btn-primary btn-sm">
        </div>


    </form>

这是我的(非工作)JS:

$("#customers-dropdown").change(function() {

    var action1 = "/ac/calendar/";
    var action2 = "/2014/12/";

    var customer = $(this).val();
    var customer_split = customer.split("-");
    var customer_id = customer_split[1].trim();

    var final_action = action1 + customer_id + action2;

    alert(final_action);

    $("#switch-customer-form").attr("action", final_action);

});

我遇到的问题是添加 .trim()到customer_id变量初始化。由于某种原因，添加此函数时它不再更改表单的 action 。没有.trim()它确实正确地更改了操作，但是存在无关的空白，导致链接不定向到适当的页面。

.trim()中有什么吗？造成这个？有没有更理想的方法来删除该变量中的空格？感谢您的帮助。

更新(为了清晰起见):

这是我成功更改表单操作的唯一 JS，尽管它仍然包含额外的空格:

$("#customers-dropdown").change(function() {

    var action1 = "/ac/calendar/";
    var action2 = "/2014/12/";

    var customer = $(this).val();
    var customer_split = customer.split("-");
    var customer_id = customer_split[1];

    var final_action = action1 + customer_id + action2;

    alert(final_action);

    $("#switch-customer-form").attr("action", final_action);

});

这没有向 <option> 添加值标签。这样做后，我遇到了同样的问题，它不更新表单操作，只是发布到当前页面。

Answer 1

这样不是更容易做到吗？ (使用id作为选择选项的值)

<form role="form"  method="post" id="switch-customer-form" class="switch-customer-form">
        {% csrf_token %}
        <div class="form-group col-xs-12 floating-label-form-group controls">
            <select class="form-control customers-dropdown" id="customers-dropdown" name="form_customers">
                {% for c in customers %}
                    <option{% if customer == c %} selected="true"{% endif %} value="{{c.id}}">{{ c }} - {{ c.id }}</option>
                {% endfor %}
            </select> 
        </div>
        <div class="form-group col-xs-12 floating-label-form-group controls">
            <input type="submit" value="View Calendar" class="btn btn-primary btn-sm">
        </div>


    </form>

$("#customers-dropdown").change(function() {

    var action1 = "/ac/calendar/";
    var action2 = "/2014/12/";

    var customer = this.value;

    var final_action = action1 + customer + action2;

    alert(final_action);

    $("#switch-customer-form").attr("action", final_action);

});

更新

This is without adding a value to the tag. Upon doing so I encounter the same issue where it does not update the form action and simply posts to the current page.

您将被重定向到同一页面，因为尚未触发更改事件并且表单中没有任何操作。如果更改事件被触发，操作就会改变并且它会起作用。

您需要向表单添加一个操作，或者添加 JavaScript 以将操作更改为在 DOM 准备就绪时标记为选中的选项。

例如，在 DOM 就绪时:

var changeAction = function(id) {
    var action1 = "/ac/calendar/";
    var action2 = "/2014/12/";    

    var final_action = action1 + id + action2;

    $("#switch-customer-form").attr("action", final_action);
};

changeAction($("#customers-dropdown").val());// On document ready, change action to selected item.
$("#customers-dropdown").change(function () {// On change event, change action as well
    changeAction(this.value);
});

fiddle