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Take a think

The browser sends a verb and an address

The Express drops it down a predefined path.

Node returns the response.

Notice something?

The server doesn’t know or care a thing about you

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REST

ReprESentaTion State Transfer:

A design paradigm at the heart of the internet
Encourages modularity
Enables scalability

Representational State Transfer is a hyper-important (or at least prevalent) topic in modern web design. It is the internet, it is http, it is many specific implementational details, but for our purposes it can be just a philosophy.

In short, it is the idea that sending data all over the place should be done by components that know and care nothing about each other but their interfaces and cannot modify or interact with each other’s internals beyond what is for allowed for in the API. Current state, implementation, even language shouldn’t matter. The interfaces should be simple and the uri’s should be descriptive and, as much as possible, intuitive.

For now, lettuce understand rest by the constraints it places on design. There must be:

Client-server separation
This separation is to be absolute. ‘Stateless’. The client and server store no information about each other’s past, present, or future internal states and every request or response contains no information about the participating agents. All requests and responses are entirely self-contained
Cachability. Perhaps not speak of this here
As a result of the above and of interface-oriented design, clients and servers should have no way of knowing if they speak to the real deal or an intermediary. This can be instrumental in scaling and adapting networks, and for security
Uniform Interface. not important for today, read it on your own time. this list is from wikipedia

That’s rest for us for now. Distinct and separated systems that pass only context-free information and implement CRUD. HTTP is THE restful protocol

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RESTful criteria:

The complete list of criteria is longer, here below are the elements that are relevant for our current understanding:

Client-server separation
Ignorance of each others’ pasts, presents, and futures
Stateless communication

“... the code is more what you'd call "guidelines" than actual rules.”

Representational State Transfer is a hyper-important (or at least prevalent) topic in modern web design. It is the internet, it is http, it is many specific implementational details, but for our purposes it can be just a philosophy.

In short, it is the idea that sending data all over the place should be done by components that know and care nothing about each other but their interfaces and cannot modify or interact with each other’s internals beyond what is for allowed for in the API. Current state, implementation, even language shouldn’t matter. The interfaces should be simple and the uri’s should be descriptive and, as much as possible, intuitive.

For now, lettuce understand rest by the constraints it places on design. There must be:

Client-server separation
This separation is to be absolute. ‘Stateless’. The client and server store no information about each other’s past, present, or future internal states and every request or response contains no information about the participating agents. All requests and responses are entirely self-contained
Cachability. Perhaps not speak of this here
As a result of the above and of interface-oriented design, clients and servers should have no way of knowing if they speak to the real deal or an intermediary. This can be instrumental in scaling and adapting networks, and for security
Uniform Interface. not important for today, read it on your own time. this list is from wikipedia

That’s rest for us for now. Distinct and separated systems that pass only context-free information and implement CRUD. HTTP is THE restful protocol

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Client-server separation:

Neither the client, nor the server have direct access to each other’s file systems or back-ends.

For security
For modularity
For efficiency
For concurrency
For persistence

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Ignorance of each other’s histories

Neither the server, nor the browser will store information about past transactions or internal states:

For efficiency
For security
For simplicity

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Stateless Communication

The big one:

Each request and each response will contain all information necessary to carry out the required action.
The current state of the sender or receiver will not be relevant to the creating and sending of the message.

You must understand this one, so discuss.

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What’s this all for?

To keep the server functional, because functional is :

Scalable
Efficient
Secure
Cross-platform
...

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pause.

Any questions? This is important.