Practical methods of PHP function form processing

Practical methods of PHP function form processing

With the popularity of Web applications, form processing has become an important content in Web development. Form processing refers to accepting data entered by users and passing it to the server for subsequent processing. PHP is a popular server-side programming language that provides many built-in functions for processing form data. This article will introduce the practical method of PHP function form processing.

1. The basic structure of the form

In HTML, a form generally consists of form, input, textarea, select and other tags. The form needs to have an action attribute and a method attribute. The action attribute is the server-side handler address when the form is submitted. The method attribute specifies the HTTP method used when submitting the form, which can be GET or POST.

In PHP, form data can be accessed through the $_GET and $_POST arrays. When the method attribute is set to GET, the form data is appended to the URL and can be accessed via $_GET. When the method attribute is set to POST, the form data is sent to the server as the HTTP message body and can be accessed through $_POST.

2. Form data verification

Before receiving form data, it should be verified first. Validating form data can use PHP built-in functions or custom functions. Here are some examples of built-in functions:

• empty() function is used to check if a form field is empty.
• The is_numeric() function is used to check whether the form field is numeric.
• The filter_var() function is used to verify whether the specified format is complied with, for example: checking whether the email address complies with the RFC 822 standard.
• The preg_match() function is used to verify whether it matches the specified format, for example: checking whether the ID number matches a specific format.

3. Form data storage

After receiving and validating the form data, it needs to be stored in the server. Typically, form data is stored in a database. Data storage can be implemented using PHP built-in functions or custom functions. Here are some examples of built-in functions:

• mysqli_query() function is used to store form data in a MySQL database.
• PDO::query() function is used to store form data in a SQLite database.
• The file_put_contents() function is used to store form data in a text file.

4. Form submission result prompt

After the form data is stored in the server, the submission result can be displayed to the user. A new page can be created that displays a submission success or failure message and provides a back button. Here are some examples:

• Use the header() function to redirect the user to a new page.
• Display a success message on the "Submission Successful" page and provide a return button.
• Display a failure message in the "Submission Failure" page and provide a return button.

5. Form Security

To protect form data from unauthorized access, form data should be protected when transmitted and stored. Here are some security measures:

• Use SSL/TLS protocol in the form to encrypt data transmission.
• Use encryption algorithms when storing form data.
• Use filter functions in input and output to ensure that malicious code is not executed.

Conclusion

PHP function form processing is an important part of web development. Implementing the complete process of the form through verification, storage, return and other steps can improve the security and reliability of web applications. Additionally, developers can create custom functions to meet specific needs.

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