Node.js + Actionhero代码未连续运行

Question

I'm obviously missing something very important about how Node.js and Actionhero work.

Can someone please explain to me why the following problem occurs:

I have this simple code: Basically it reads a .css file .

buildAdsHTML: function (ads, type) {
        var cssDir = path.normalize(__dirname + '/../public/css/');
        switch (type) {
            case  'text':
                var result = '';
                console.log("STEP 1");
                fs.readFile(cssDir + type + 'Ads.css', {encoding: 'utf8'}, function (err, data) {

                    console.log(err);
                    console.log(data);
                    if (!err) {

                        console.log("STEP 2");
                        result += '<style>' + data + '</style>';

                    } else {

                    }
                });

                break;

        }
        console.log('STEP 3');
        return result;
    }

Now when this code is run I get an empty string as result. The console output is the following:

STEP 1 <- so far so good 
STEP 3<- this should be last!

null <- this is the error variable 

.some-random-css-class{
    display: block;
    width: 100;
    min-height: 250px;
}

STEP 2

Now at some point I figured out that that fs.reafFile is async function. So I naturaly changed it to the sync version fs.readFileSync . Now the console output is even worse:

STEP 1
STEP 3

Thats it! Nothing else. And I still get a empty string as result. Like the whole code isnt even going through the swich .

I've noticed this behavior in all functions and methods of my actionhero project, most notebly when calling next(connection) . You can't just call it at the end of the method.

For every if or swich I have to call it inside to have any actual control over the result.

Otherwise every new data I've added to the connection is lost.

What's with that ? Please explain that functionality in detail so I don't make any dumn mistakes while coding.

Answer 1

Finaly figured it out.

The problem was that I didnt notice that fs.readFileSync had no callback funtction.

So the proper use for that function should have been

var result= fs.readFileSync(pathToFile,{options})
return result;

I can still use some help on the problem i mentiond with next(connection); . I dont realy know why it skips whole parts of code like that.

Answer 2

I've found next() doesn't like it if you pass it any parameters. I had a bug in my application for a good day or two because I was doing '.then(next);'