Validation class of codeigniter class library

In BS programming, we often need to verify the data submitted by the customer. Each scripting language has its own Authentication mode, and codeignite also provides a set of very useful class libraries-validation class.

Like other class libraries, You need to load them before using the validation class.

$ This-> load-> Library ("validation ");

After loading, we can use $ this-> Validation to reference it. Some may ask, "How does it know what data I want to verify and what rules I want to verify ?" This is what we will talk about below.

The loaded validation class can't do anything. Even if it calls its run method, its return value is always false, because we didn't specify a validation rule for it. Codeigniter predefines some rule references.

Rules	Parameters	Description	Example
Required	None	Required field
Matches	Yes	Matches the specified parameter.	Matches [form_item]
Min_length	Yes	Minimum Length	Min_length [6]
Max_length	Yes	Specify the maximum length	Max_length [12]
Exact_length	Yes	Specify the numerical precision	Exact_length [4]
Alpha	None	The input must be a letter
Alpha_numeric	None	The input must be a letter or Digit
Alpha_dash	None	The input must be a letter or a lower part or minus sign.
Numeric	None	The input must be a numeric character only.
Valid_email	None	Enter a valid email address.
Valid_ip	None	Enter a valid IP address.

Assume there is a page for user registration information verification. There is an input box named user, a password input box named password, and a Password confirmation box named confirm on this page, we can define verification rules as follows:

$ Rule ['user'] = "reguired"; $ rule ['Password'] = "required | min_length [6]"; $ rule ['Confirm'] = "required | matches [Password]"; $ this-> Validation-> set_rules ($ rule );

After the verification rules are defined, we can call the run method for data verification.

If ($ this-> Validation-> Run () = false) {// Verification Failed} else {// Verification Successful}

Use$ This-> Validation-> error_stromgYou can get the prompt message after the verification fails.

All of the above are verification rules defined in advance using codeigniter. What should we do if we want to customize verification rules? This is also very simple. We only need to write a verification function and specify it to validation.

// User-defined authentication username function. Do not add "callback _" function username_check ($ Str) {if ($ STR = "admin") to the function name ") {$ this-> Validation-> set_message ("username_check", 'the % s field can not be the word "admin" '); retrun false;} else {true ;}} $ rule ['user'] = "callback_username_check"; // before the function name is verified, add "Callback _" $ this-> Validation-> set_rules ($ Tule );