Extension Globals

PHP extensions provide a way to define globals within an extension. Reading/writing globals should be faster than any other global mechanisms (like static members). You can use extension globals to set up configuration options that change the behavior of your library.

In Zephir, extension globals are restricted to simple scalar types like int/bool/double/char, etc. Complex types such as string/array/object/resource are not allowed here.

You can enable extension globals by adding the following structure to your config.json:

{
    "globals": {
        "allow_some_feature": {
            "type": "bool",
            "default": true,
            "module": true
        },
        "number_times": {
            "type": "int",
            "default": 10
        },
        "some_component.my_setting_1": {
            "type": "bool",
            "default": true
        },
        "some_component.my_setting_2": {
            "type": "int",
            "default": 100
        }
    }
}

Each global has the following structure:

"<global-name>": {
    "type": "<some-valid-type>",
    "default": <some-compatible-default-value>
}

Compound (namespaced) globals have the following structure:

"<namespace>.<global-name>": {
    "type": "<some-valid-type>",
    "default": <some-compatible-default-value>
}

The optional module key, if present, places that global’s initialization process into the module-wide GINIT lifecycle event, which just means it will only be set up once per PHP process, rather than being reinitialized for every request, which is the default:

{
    "globals": {
        "allow_some_feature": {
            "type": "bool",
            "default": true,
            "module": true
        },
        "number_times": {
            "type": "int",
            "default": 10
        }
    }
}

In the example above, allow_some_feature is set up only once at startup; number_times is set up at the start of each request.

Inside any method, you can read/write extension globals using the built-in functions globals_get/globals_set:

globals_set("allow_some_feature", true);
let someFeature = globals_get("allow_some_feature");

If you want to change these globals from PHP, a good option is include a method aimed at this:

namespace Test;

class MyOptions
{

    public static function setOptions(array options)
    {
        boolean someOption, anotherOption;

        if fetch someOption, options["some_option"] {
            globals_set("some_option", someOption);
        }

        if fetch anotherOption, options["another_option"] {
            globals_set("another_option", anotherOption);
        }
    }
}

Extension globals cannot be dynamically accessed, since the C code generated by the globals_get/globals_set optimizers must be resolved at compilation time:

let myOption = "someOption";

// will throw a compiler exception
let someOption = globals_get(myOption);