From 2e6efbd587e88be19b0c8f34d1597448125e23cf Mon Sep 17 00:00:00 2001
From: Emiel Bruijntjes
+ Let's get one thing clear first. Running native code is much faster than
+ running PHP code. So, once your C++ function or your C++ method finally
+ gets called, you normally cast the parameters to native variables, and
+ you start running your own fast algorithm. And you don't want to call
+ other PHP functions from that moment on.
+
+ If, however, you would like to make a call to a PHP function - whether that
+ is a function that is built-in in the Zend engine, that is defined in an
+ extension, or even a function that comes from PHP user space - you can do
+ so.
+
+Calling PHP functions
+
+#include <phpcpp.h>
+#include <iostream>
+
+/**
+ * Native function that is callable from PHP
+ *
+ * This function gets two parameters: an associative array and a callback.
+ * It does not do anything meaningful, it is just a demonstration function.
+ *
+ * @param params The parameters passed to the function
+ */
+void example_function(Php::Parameters ¶ms)
+{
+ // first parameter is an array
+ Php::Value array == params[0];
+
+ // call the PHP array_keys() function to get the parameter keys
+ std::vector<std::string> keys = Php::array_keys(array);
+
+ // loop through the keys
+ for (auto &key : keys)
+ {
+ // output key
+ std::cout << "key: " << key << std::endl;
+ }
+
+ // call a function from user space
+ Php::Value data = Php::call("some_method", "some_parameter");
+
+ // create an object (this will also call __construct())
+ Php::Object time("DateTime", "now");
+
+ // call a method on the datetime object
+ std::cout << time.call("format", "Y-m-d H:i:s") << std::endl;
+
+ // second parameter is a callback function
+ Php::Value callback = params[1];
+
+ // call the callback function
+ callback("some","parameter");
+
+ // in PHP it is possible to create an array with two parameters, the first
+ // parameter being an object, and the second parameter should be the name
+ // of the method, we can do that in PHP-CPP too
+ Php::Array time_format(time, "format");
+
+ // call the method that is stored in the array
+ std::cout << time_format("Y-m-d H:i:s") << std::endl;
+}
+
+/**
+ * Switch to C context, because the Zend engine expects get get_module()
+ * to have a C style function signature
+ */
+extern "C" {
+ /**
+ * Startup function that is automatically called by the Zend engine
+ * when PHP starts, and that should return the extension details
+ * @return void*
+ */
+ PHPCPP_EXPORT void *get_module()
+ {
+ // the extension object
+ static Php::Extension extension("my_extension", "1.0");
+
+ // add the example function so that it can be called from PHP scripts
+ extension.add("example_function", example_function);
+
+ // return the extension details
+ return extension;
+ }
+}
+ In above example you can see quite some different ways how to call PHP + functions from C++. The first one is the call to Php::array_keys(). The + PHP-CPP internally has a long list of all important PHP functions, and + you can call these functions directly from your extension. Php::array_keys() + is one of them. +
++ Many of the built-in function functions (like Php::array_keys()) return a + Php::Value object. In the example however, you saw that we assigned the + return value directly to a std::vector. This works because the Php::Value + object has an implicit casting operator to automatically transform the + object to a vector. +
++ Not every PHP function can of course be called like the built-in functions + can. User space functions, or functions from optional PHP extensions are not + automatically forwarded by the PHP-CPP library. Such functions can still be + called by using the Php::call() function. You must supply the name of the + fuinction to call, and a list of optional arguments to call a function + from user space. +
++ The Php::Object class (which is derived from Php::Value) can be used to + create objects, and implicitly call the __construct() method. To call a + method on an object, you can use the method Php::Value::call() method, which + is used in the example to call the PHP method DateTime::format(). +
++ In PHP scripts you can create an array with two members: and object and + the name of a method. This array then automatically becomes callable. You + can do similar things in C++ as well, as we showed in the example with the + "time_format" variable. +
++ The following script runs the example. +
++
+<?php
+ // example input
+ $input = array(
+ 'x' => 10,
+ 'y' => 20,
+ 'z' => 30
+ );
+
+ example_function($input, function($param) {
+ echo("callback called with param $param\n");
+ });
+?>
+
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