safari扩展中的全局变量

Question

How can i have a global variable in safari extension that can be acceded from injected script, and can be saved for the next launch after safari is closed.

and by global i mean static.
so that all injected script access the same version of that variable not every injected script has it's own.
and not like localStorage that is per domain.

Answer 1

The Safari extension settings API might be the best thing to use for this. This works similarly to localStorage and is accessible via safari.extension.settings .

However, this isn't accessible directly from injected scripts, so you have to use messages to pass data from a global page .

Something like this in your injected script:

safari.self.addEventListener('message', handleMessage, false);

safari.self.tab.dispatchMessage('getSetting', 'myVar');

function handleMessage(msg) {
    if (msg.name === 'returnSetting') {
        var setting = msg.message;
    }
}

And in your global page:

safari.application.addEventListener('message', handleMessage, false);

function handleMessage(msg) {
    if (msg.name === 'getSetting') {
        var setting = safari.extension.settings(msg.message);
        safari.application.activeBrowserWindow.activeTab.page.dispatchMessage('returnSetting', setting);
    }
}

Alternatively, you could do more or less the same thing with localStorage within the domain of the global page, so it isn't restricted to web pages of one domain.