dothat

Dothat.js

Promise-Based Behavioural Facade DSL tools.

• Extendable Promise A+ compliant base Class
• aimed to define "Driver DSLs"
• which allow to pilot easily complex behavioural object
• by mixing Facade Method Chaining and Promises pipe pattern
• written in ES6 (avaiable in both es5 and es6)

Final aim is to provide easy Facade tools that hide technical details and/or targets inhomogeneities behind well choosed abstract DSLs. It's the little sister of Babelute.js.

Dothat is "Behaviour Oriented" and Babelute is "Fact Oriented".

Lighweight (2.0 Ko minified gzipped) and so useful.

Usage

First of all, a Dothat is just like a Promise A+ (in fact it is a Promise A+ with just a second argument that is forwarded in each then/catch). So everywhere the program accepts a Promise, it accepts a Dothat.

var promise = new Dothat(function(resolve, reject){
    resolve(2);
});
 
promise.then(function(s){
    if(s < 4)
        throw new Error('bam!');
})
.catch(function(e){
    console.error('error : ', e); // bam!
});
 

But its aim is to be extended with "Facade" DSL lexems.

// simple example of direct Dothat prototype extension
Dothat.prototype.myMethod = function(arg1, arg2, ...){
        return this.then(function(success, subject){ // note the second argument
            // do wathever you want with arg1, arg2, ... and success (the Promise piped value)
            // on subject
        });
};
Dothat.resolve("my first success", mySubject) // note the second argument
    .myMethod(true, "arg2_value", ...)
    .then(...)

You could off course extends any DSL's Class.

// Dothat derivated class
var MyDSL = Dothat.extends(Dothat, {
        myMethod : function(arg1, arg2, ...){
            return this.then(function(success, subject){
                // do wathever you want with arg1, arg2, ... and success (the Promise piped value)
             	// on subject
           	});
      }
});
MyDSL.resolve("my first success", mySubject)
    .myMethod(true, /*...*/) 
    .then(/*...*/)
MyExtendedDSL = Dothat.extends(MyDSL, /*...*/);
//...

Remarque : you could use ES6 class extension syntax, but by using MyDSL.extends you receive in addition 2 static methods (resolve, reject) binded to needed Class that are useful. So keep that in mind if you use ES6 class syntax. Whatever, keep thing simple... ;)

Little sugar :

const MyDSL = Dothat.extends(Dothat, {
    myLexem:function(myArg){
        return this.then(function(s, subject){
            return subject.title = s;
        });
    }
});
const mydsl = MyDSL.resolve,
    subject = { title:'bar' };
 
mydsl(1, subject).myLexem('goo').log('result'); // result : "goo	"
 
// subject = { title:'goo'}
 
//...

More serious :

const AppDSL = Dothat.extends(Dothat, {
    login(email, pass){ 
        return this.then((s, app) => {
            return myClient.post(app.baseURI + '...', { email, pass })
        })
        .then((s, app) => {
            app.loggedIn = true;
            app.session.userId = s.userId;
            app.session.token = s.token;
            app.session.save();
            return true;
        });
    },
    logout(){
        return this.then(/*...*/);
    },
    register(email){
        return this.then(/*...*/);
    },
    route(route){
        return this.then(/*...*/);
    },
    email(opt){
        return this.then(/*...*/);
    }
    //...
});
 
function app(myApp){ 
    return AppDSL.resolve(null, myApp);
}
 
app(myApp)
    .login('[e-mail]', '12345')
    .route('/my/state')
    .log('result')
    .catch((e, appli) => {
        return app(appli).email({ /*...*/ });
    });
 

Licence

The MIT License

Copyright 2017 (c) Gilles Coomans [e-mail]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.