Grunt redirect rest call to file

Question

I am using grunt connect server with all those livereload plugins. Developing process was very fast till I added some rest calls. I decided to make some example JSON files which ll be rest calls answers.

So I need to redirect every rest call to some static folder(important I ll put it in target folder) so it ll be outside the Angular folder.

So I need some plugin which transfer calls like:

http.get(localhost:port/x/y/name) to target/jsons_examples/x/y/name.json
http.get(localhost:port/z/name) to target/jsons_examples/z/name.json

grunt file:(1 aplication server, 1 mocking webservices)

grunt.initConfig({
  connect: {
  all: {
    options: {
        port: 10100,
        hostname: "0.0.0.0",
        livereload: true
    }
  },
  webservices_mock: {
    options: {
        port: 8081,
        hostname: "0.0.0.0",
        middleware: function(connect, options, middlewares) {
            middlewares.unshift(function(req, res, next) {
                var pattern = new RegExp('\/rest\/[a-zA-Z0-9\/.]+', 'i'),
                    matches = req.url.match(pattern);

                if (!matches) {
                    return next();
                }

                req.setEncoding('utf8');
                res.writeHead(200, {"Content-Type": "application/json"});
                res.write(grunt.file.read(req.url.replace("/rest", "json_contracts") + "/example.json"));

                res.end();
            });

            return middlewares;
        }
    }
  }
},
...

And now i need in web services mock configuration change the path from json_contracts to path outside angular folder smth like: ././././target/json_contracts

Answer 1

You can use middleware option to inject your own URL parser. See the comments to understand how it works:

grunt.initConfig({
  connect: {
    all: {
      options:{
        port: 8080,
        base: dir_to_angular_main_folder
        hostname: "localhost",
        middleware: function(connect, options, middlewares) {
          middlewares.unshift(function(req, res, next) {
            // pattern is a RegExp which is going to find the redirected url
            var pattern = new RegExp('^/x/y/([0-9A-Z]+)$', 'i'),
                // matches is a result which is
                //  - undefined when no match found
                //  - an array with two values when found:
                //    0: the full string
                //    1: the string inside of the brackets (the file name)
                matches = req.url.match(pattern);

            // if your url does not match skip the bottom part
            if (!matches) return next();

            // this runs only if match is found, set up the redirect header
            // up to you to decide whether it is 301 or 302
            // I would keep it 302 for dev purposes (browsers won't cache it)
            res.writeHead(302, {
              Location: '/target/jsons_examples/x/y/' + matches[1] + '.json'
            });

            // send the response
            res.end();
          });

          return middlewares;
        }
      }
    }
  }
});

I guess you will still need to change the pattern to the one you need (x / y / target don't sound as real names).

One can say you can do it easier without matching like this ([0-9A-Z]+) and using the matches here '/target/jsons_examples/x/y/' + matches[1] + '.json' and he will be right. It was made with a name only because it is more flexible, e.g. when you have a folder in between x and y etc. Anyway, as it was said before, you can also make it simpler and just use the following:

res.writeHead(302, {
  Location: '/target/jsons_examples' + req.url + '.json'
});

I could not test it, maybe it gives you some errors, but still I hope this is good enough to give an idea what and how to do.

EDIT

Well, according to the fact that your JSON files are not visible from the webserver side (the root folder is out of scope) you can do some kind of url rewriting instead of redirect:

var fs = require('fs');

grunt.initConfig({
  connect: {
    all: {
      options:{
        port: 8080,
        base: dir_to_angular_main_folder
        hostname: "localhost",
        middleware: function(connect, options, middlewares) {
          middlewares.unshift(function(req, res, next) {
            // pattern is a RegExp which is going to find the redirected url
            var pattern = new RegExp('^/x/y/([0-9A-Z]+)$', 'i'),
                // matches is a result which is
                //  - undefined when no match found
                //  - an array with two values when found:
                //    0: the full string
                //    1: the string inside of the brackets (the file name)
                matches = req.url.match(pattern);

            // if your url does not match skip the bottom part
            if (!matches) return next();

            // this runs only if match is found, set up the redirect header
            // reads the file content and sends as a response
            res.end(fs.readFileSync('/<some-absolute-path>/target/jsons_examples/x/y/' + matches[1] + '.json', 'utf8'));
          });

          return middlewares;
        }
      }
    }
  }
});

Note that you need to include the Nodejs standard fs module on the top of your Gruntfile to make it work. This is again just a prototype, change the paths according to your requirements. Maybe you would also need to write the mime-type as a header of your response, there are already many answers on how to do it in Node as well.