How to tell if JsPrintSetup is loaded

[bogal]

Is there any way to detect whether the browser has JsPrintSetup installed or not?

[cye060]

This is a section of code i use to grab available printer list and also works to detect if JsPrintSetup is loaded also. I'm sure there may be better ways but this way does work.

    try
    {
        var content = jsPrintSetup.getPrintersList();
        window.location.href = "User_Edit.php?name=" + content;
    }
    catch (exception)
    {
        console.error(exception);
        window.alert('Your browser is not supported for client side printer selection or printing at this time, sorry.');
        window.location.href = "User_Edit.php?name=null";
    }

[mitkola]

At first you can check whether jsPrintSetup addon is installed and suggest installation.

jsPrintSetup_CBIntall = function(name, result){
    if(result == -210){
        alert('Install of Extension: \n'+name+'\n was canceled.\n Result: '+result);
    } else {
        alert('Extension: \n'+name+'\n was installed sucessfully.\nResult: '+result);
    }
} // jsPrintSetup_CBIntall

function jsPrintSetup_checkInstall() {
    if (typeof(jsPrintSetup) == 'undefined') {
        if (confirm('Do you want to install jsPrintSetup?')) {
            var xpi = new Object();
            xpi['jsprintsetup'] = 'https://addons.mozilla.org/firefox/downloads/latest/js-print-setup/addon-8966-latest.xpi';
            InstallTrigger.install(xpi, jsPrintSetup_CBIntall);
        }
    }
}

Another thing to consider is Access Control, here can find how to check it.