Php-cpp Development Extension (ii)

Php-cpp is a C + + library for developing PHP extensions. This section explains the implementation of PHP output and functions.

Output and Errors

In the HelloWorld example above, we used the Php::out output and used a std::endl newline refresh buffer. Php::outA variable is actually std::ostream an instance of the class that supports all the output buffers set in PHP. It is basically the same as a function in a PHP script echo() .

Several common ways to explain:

• std::flushDisplay refresh buffer;
• std::endlOutput line break and refresh buffer;
• Php::outOutput content to buffer;
• Php::noticeGenerate a PHP notice;
• Php::warningGenerate a PHP warning;
• Php::deprecatedGenerate a PHP deprecated;
• Php::errorGenerate a PHP error

For errors, notifications, and warnings, we don't need a newline character, but we still have to flush the buffer to actually generate the output. Php::errorflow has something very special: when you refresh it, the PHP script ends with a fatal error.

With some of the above methods, we can implement the standard output function of PHP.

The use of output must introduce a iostream header file.

Implementing PHP Functions

In the above example, we've actually implemented 2 PHP functions. Next, let's look at how Php-cpp implements the following 4 kinds of functions:

• Invisible parameter no return value
• The invisible parameter has a return value
• No return value for physical parameters
• Tangible parameters have return values

Thanks to the php-cpp packages Php::Value and Php::Parameters classes, we can implement these functions very simply.

Php::ValueCan be thought of as PHP variables, the internal encapsulation of the ZVAL structure. By overloading the operators, variables in C + + support automatic conversion to Php::Value type.

1. No return value for invisible parameter

void func(){}

2, the invisible parameter has the return value

Php::Value func(){}

3. No return value for tangible parameters

void func(Php::Parameters &params){}

4, the tangible parameter has the return value

Php::Value func(Php::Parameters &params){}

Example:

/** * User: 公众号: 飞鸿影的博客(fhyblog) * Date: 2018/7 */Php::Value sum_n(Php::Parameters &params){    int max = 0, sum = 0;    if(params.size() == 0){        Php::warning << "miss param" << std::flush;        return 0;    }    max = params[0];    if(params[0].type() != Php::Type::Numeric){        Php::warning << "param type must be numeric." << std::flush;        return 0;    }    for(int i = 1; i <= max; i++){        sum += i;    }    return sum;}

The function realizes the return value of the tangible parameter, and several other modifications can be realized. Although the function returns a C + + int type variable, it is Php::Value automatically converted to the PHP language type variable.

We only need to get_module() register in:

extension.add<sum_n>("sum_n");

Tips: The final exposed function name can be different from the C + + functor name, for example:

extension.add<sum_n>("sum_n2");

is also possible.

To recompile, you can:

$ sudo make clean && make && sudo make install

(not to be continued)

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Php-cpp Development Extension (ii)