jquery sets text read-only

jQuery is a JavaScript framework widely used in web development. It allows developers to operate HTML documents, parse and process XML documents, and perform Ajax interactions in a simpler, faster and more convenient way. During the development process, we often encounter the functional requirement of "read-only". For example, the input box can only be displayed and users are prohibited from editing. This article will introduce how to use jQuery to set a text box to read-only mode.

First of all, we need to understand the read-only attribute of the text box. The input element in HTML has a readonly attribute. By setting this attribute to "true" or "readonly", the read-only function of the text box can be achieved. As shown below:

<input type="text" readonly="true"/>
<input type="text" readonly="readonly"/>

One of the attribute values ​​​​is "true" and the other is "readonly". The effect of the two methods is the same. When the text box is set to read-only attribute, the user will not be able to manually modify the text box content on the page. However, it can still be set, reset, or modified via JavaScript.

So how to use jQuery to set text read-only? We can use the .attr() method to set the readonly attribute of the text box. The method syntax is as follows:

$(selector).attr(attribute,value)

Among them, selector represents the element to be selected, attribute represents the attribute name to be set, and value represents the attribute value. In order to set a text box to read-only mode, we can use the following code:

$(selector).attr("readonly", true);

The selector in the above code can be the element name of the text box (input, textarea) or its ID or class name and other identifiers . When we run the above code, jQuery will set the "readonly" attribute value of the specified text box element to "true", thus achieving the read-only mode setting.

In addition, we can also use the .prop() method to set the read-only attribute of the element. The prop() method is very similar to the .attr() method in setting attributes, but the .prop() method handles different types of attributes better, such as the "checked" attribute of a checkbox. The following is the code that uses the .prop() method to set the text box to read-only mode:

$(selector).prop("readonly", true);

The essential difference between the two methods is that the .prop() method can only be used for Boolean attributes, while the .attr () method can be used on any attribute. In practical applications, we can choose to use different methods according to specific needs.

It is worth noting that implementing read-only mode is not completely safe, nor can it completely prevent users from modifying the page. If more secure data protection measures are needed, we need to use other technical means, such as encryption algorithms, server-side verification, etc.

In short, using jQuery for element manipulation is one of the techniques that our developers often use. Setting a text box to read-only mode is also a very useful trick that can lead to better user experience and data protection. The above code can also be used for other elements such as drop-down menus, buttons, etc. Hope this article can be helpful to you.

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