jquery form reset cannot be used

Preface

In the process of developing web applications, the use of forms is naturally indispensable. Forms allow us to collect user-entered information and use it for subsequent data processing and display. In the implementation of the form, we need to frequently use the form reset function, which also involves jQuery's form reset method. However, sometimes we may find that the input box in the form is not cleared, and the form.reset() method does not work, which makes the development process extremely difficult. In order to solve this problem, we need to delve into why the form reset method does not work and how to solve this problem.

Problem Analysis

First of all, we need to understand the principle of jQuery's form reset method. In jQuery, the form reset method is used to reset form elements. By calling the form reset method, the content filled in the form can be reset to a null value, which is equivalent to the state when the form is reopened. The specific usage method is as follows:

$('form')[0].reset(); // 重置表单

Generally speaking, this method is used to clear the input box in the form so that the user can refill it. However, in some cases, this method can cause some problems. For example, when we use some special form elements, the form reset method may fail. Especially when we use some custom form controls, the function of resetting the form may not be possible.

In order to better solve this problem, we need to further analyze the reasons why the form reset method fails. In the actual code development process, we will find that the form reset method is not always able to clear the content of the input box, and some other problems will occur. These problems include:

1. Custom controls cannot be reset
2. The password input box cannot be cleared
3. The selection box using the jQuery select2 plug-in cannot be reset
4. The default value of the date selection box cannot be reset

We need to solve these problems one by one.

Problem Solving

1. Custom controls cannot be reset

For the situation where custom controls cannot be reset, we can manually clear the value of the control to solve. For example, on a custom input box, we can implement the reset function through the following code:

$('#custom-input').val('');

This can force the content in the input box to be cleared. If there are multiple custom controls that need to be reset, we can do it through a loop:

$('.custom-control').each(function() {
  $(this).val('');
});

In this way, all custom controls can be traversed and their values ​​​​forcibly cleared.

2. The password input box cannot be cleared

For the situation where the password input box cannot be cleared, we need a slightly more complicated solution. Generally speaking, if the user enters a password in the input box, then we cannot obtain its value. Therefore, we need to modify the type attribute of the password input box so that it is no longer of password type, and then modify it back after resetting it. The specific code is as follows:

var passwordInput = $('#password-input');

// 将输入框类型改为 text 类型
passwordInput.attr('type', 'text');

// 清空输入框
passwordInput.val('');

// 将输入框类型修改为 password 类型
passwordInput.attr('type', 'password');

In this process, we need to pay attention to modifying the type attribute of the input box, otherwise the password input box will still display the entered password after the reset.

3. The selection box using the jQuery select2 plug-in cannot be reset

For the situation where the selection box using the jQuery select2 plug-in cannot be reset, we can call the select2 method to implement force Empty. The specific code is as follows:

$('#select2-input').val(null).trigger('change');

In this method, we use the val method of the select2 plug-in to forcefully clear the value of the selection box, and trigger the change event through the trigger method to update the status of the selection box.

4. The default value of the date selection box cannot be reset

Finally, for the situation where the default value of the date selection box cannot be reset, we can manually modify the date selection box value attribute. The specific code is as follows:

$('#datepicker').attr('value', '');

This way you can clear the default value in the date selection box and set it to empty after resetting.

Conclusion

Through analysis, we found that jQuery’s form reset method is not omnipotent, and sometimes there will be some unsolvable problems. Therefore, in the actual development process, we need to be more flexible in thinking and solving problems. When there are some unsolvable problems, we should solve the problem based on the actual situation rather than relying rigidly on a certain method. I hope this article can help everyone solve similar problems and improve the efficiency and quality of code development.

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