Hey there, and welcome to the deep dive.
If you're looking to cut through the tech jargon and get straight
to what really matters in complex topics, well, you're in
the right place. Today we're tackling something
pretty foundational in software engineering, the model, view
controller, or MVC pattern. You might not realize it, but
this architecture has quietly shaped how we interact with
digital applications every single day.
We've got some fantastic source material that really unpacks
MVC, tracing its evolution from its, you know, pioneering
origins right up to the web applications and single page
apps we use constantly. Now, our mission, it's simple to
give you a clear understanding of what MVC actually is, why
it's been so powerful for so long, and how it's adapted over
the decades. OK, let's peel back the layers.
Let's see how this classic design still underpins so much
of our digital world. It really is fascinating.
Is it? What our sources highlight is
how a design pattern thought up, you know, decades ago continues
to be so relevant in modern software.
We'll definitely trace that history and hopefully we can
clear up some of the common confusions people have about it
along the way. Right.
And to really get MVC, we kind of have to rewind, don't we?
Back to the late 1970s. It's hard to imagine now, but
this was an era dominated by text based command line stuff.
Screens were just characters. But then this truly
groundbreaking object oriented language popped up.
Small Talk 80. Exactly.
Small talk 80. It wasn't just about object
oriented programming, though that was huge.
It was a massive leap forward in making graphical user
interfaces, Guis, accessible. We're talking the first real
widespread use of Windows buttons, scroll bars, even the
mouse for like a broader audience.
It was a completely radical shift in how people interacted
with computers and MVC. That was the architectural
pattern small talks designers picked to actually build these
complex graphical interfaces. OK, so in that context, this
brand new GY world, what exactly was MVC proposing?
Our sources explain it, introduce this well, paradigm
shifting idea. System classes should be
organized into 3 distinct, pretty specialized groups.
Yeah, let's break those down because understanding these core
jobs is really key. First, the view.
These are the classes directly responsible for the graphical
interface itself. You know everything you see and
interact with. The windows, buttons, menus, the
visual display a. Little frent end stuff
basically. Pretty much.
Then you have the controller. These classes are like the
listeners. They handle events coming from
input devices, a mouse click typing on the keyboard.
A controller then figures out what that input means and can
ask for changes either to the models data or maybe the views
appearance. So like clicking A+ button on a
calculator, the controller tell the model hey update your
calculation. Or maybe clicking a dark UI
button the controller tells the view change your colors.
Got it. Input handler and director.
Kind of. Exactly.
And 3rd, crucially, there's the model.
These classes are where the applications Core Data and it's
business logic actually live. They hold the what of the
application and they're completely unaware of how that
data gets displayed or how users interact with it.
They don't know about the view or the controller, No dependency
there. They just manage the application
state and you know the operations on that data.
So putting it together, the graphical interface part, what
the user sees and clicks is essentially split between the
view and the controller. But our storage material also
flags that this distinction. Well, it isn't always perfectly
clean in practice. Sometimes it simplifies more to
just graphical interface plus model.
Is that a common thing? That's a really sharp
observation, and yes, absolutely true.
As Martin Fowler points out and one of our sources, even way
back in the small talk days, many implementations didn't
always keep a super strict separation between view and
controller. The fundamental insight though,
the real take away is this key deendency direction.
The graphical interface, the view controller combo.
It deends on the model, but the model, the data and the core
logic, it stays completely independent, knows nothing about
the graphics. You can kind of picture it like
the graphical interface is constantly watching the model.
When the model state changes, the interface knows OK, I need
to update myself. OK, that separation of concerns
sounds incredibly useful, especially when you think about
building bigger, more complex applications.
What are the big advantages this pattern brings?
Oh, there are several really compelling reasons NBC caught on
so widely and why it's still relevant.
First, specialization of development work.
It really lets teams specialize. You can have front end folks who
are experts in UI focusing just on the view and controller, and
then other developers can concentrate purely on the models
tricky business logic without needing to get bogged down in UI
code. It just streamlines things a
lot. Makes sense.
Divide and conquer, right? Second, multiple views for the
same model. Think about having the same
underlying data shown in totally different ways.
NBC makes this pretty straightforward.
Our source gives a great example, a model that just
stores hours and minutes. That same model can power both
an old school analog clock face and a digital time display at
the same time. That gives you huge flexibility
and helps reuse code. Yeah, I can see that like
different dashboards showing the same core data.
Exactly. And 3rd, enhanced testability.
Things without a visual component like the classes in
your model are just inherently easier to write automated tests
for. By separating the view and
controller cleanly from the model, develoers can test the
core business logic much more thoroughly, much more
efficiently. And that leads to, you know,
more robust software. Yeah, testing GUI is notoriously
tricky, so isolating the logic helps massively there.
And the source really hammers this home with that powerful
quote from Fowler and Beck, calling the separation of UI
code and domain logic the gold at the heart of MVC.
What is it about that specific separation that's so profoundly
useful for developers? It's so impactful because it
tackles complexity head on. Building software is hard, right
by drawing a really clear line between what the application
does, the business rules, the data that's the model and how it
was presented to the user and interacted with the view and
controller. You basically create these
modules, these pieces that are much simpler to change, to
maintain, and to evolve independently.
This fundamental separation leads to cleaner code, it's more
modular, and critically, it lets you have multiple different ways
of presenting the exact same business logic without having to
copy that core logic all over the place.
OK, that really clarifies the core value.
Now, something that often trips people up is the relationship
between MVC and three tier architectures.
Our source gives a great historical perspective to
untangle this. How did these two concepts
relate initially? Yeah, this is a really important
distinction to make because they are both architectural patterns,
but their origins and their main goals were actually quite
different back in the day. So MVC's genesis, like we said,
MVC came about in the late 70s specifically to deal with the
complexity of Guis inside single applications.
Think early desktop software, maybe an office suite like Word
or Excel. Right, self-contained
applications. Exactly.
Then, three tiers emergence. Fast forward to the 1990s.
The whole world is changing with networks, distributed systems
becoming the norm. 3 tier architectures really rose to
prominence. Then they separated the system
into distinct layers. A client, usually the user
interface layer, an application layer with a business logic
lived off and on a server and a database layer for storage.
Now in that kind of setup, NBC wasn't really a competitor.
It could actually be used inside the presentation layer, the
client layer of a bigger 3 tier system.
You might have had, say, a complex Windows application
using MVC for its UI, but that application was just one part of
a larger distributed system. Ah.
OK, so it wasn't an either situation back then.
It was more like MVC could be part of a tier in a three tier
system like Russ and Dolls almost.
That clears up a lot of that historical confusion for me.
But then then the web happened. Everything changed again.
Absolutely. The web just exploded around the
year 2000, became ubiquitous, and suddenly user interfaces
weren't complex desktop apps anymore.
They were migrating to HTML and JavaScript running inside web
browsers. And this is where the lines
really started to blur, mainly because these new powerful web
frameworks started popping up. Things like Spring in the Java
world, Ruby on Rails, Django and Python, Blairville and PHP, and
they all decided to call themselves MVC frameworks.
OK, so they adopted the name MVC, but given how different the
web is, stateless request response.
Was it the same NBC as the Small Talk original or was it more of
an adaptation? It was definitely an adaptation,
A reinterpretation really tailored for the web specific
nature. In these these web frameworks,
the view typically became dynamic HTML pages, often
generated on the server side. The controllers became
components that handled incoming web requests, figured out what
data was needed from the model, and then decided which view to
render and send back to the browser.
And the model layer, well, that often became primarily about
data persistence, the code to talk to the database.
So while these modern web systems functionally often look
a lot like 3 tier systems, these incredibly popular frameworks
chose to use those familiar MVC terms, and that fundamentally
shaped how developers thought about building web apps for
many, many years. Right.
So maybe the best way for us to think about it now is that there
are kind of two main flavors, the original classic small talk
80 version for GOYS and then this widely adopted web version,
which as you explained, bars the terms, but acts a lot like a
three tier setup tailored for the web.
That's a very good way to summarize it. 2 distinct
contexts, similar terminology causing a bit of confusion
sometimes. OK, let's Fast forward again.
The web hasn't stood still. Obviously we've seen another
major shift with single page applications Spas.
How do these more modern dynamic client heavy applications fit
into the MVC picture? That's a great next step,
because Spas really did change the user experience on the web.
Think about traditional web as often every time you click
something or submit a form, the browser has to go back to the
server, get a whole new page, and redraw everything.
That can feel slow, a bit clunky.
SB As aim to fix that to make web apps feel much more like
native desktop applications right there in your browser.
So less of that constant page reloading, that flash of white
screen, more fluid. Exactly when you first load an
SBA, something like Gmail is a classic example.
The browser downloads most of the applications code upfront,
the HTML structure, the CSS for styling, and crucially, a lot of
JavaScript. From then on, when you interact
with it, most of the action happens right there in your
browser. The logic and the presentation
rendering are largely client side.
That's what creates that much smoother, much more interactive,
responsive feel. But even though all this magic
is happening in the browser, they still need to talk to a
server for data, right? It's not completely offline.
Absolutely. There's definitely still a
server component. You need somewhere to store the
data permanently, handle authentication, perform complex
operations. When an SPA needs new data,
maybe new emails arrive in Gmail.
It communicates asynchronously with the server, usually using
AP is it fetches just the new data it needs and updates only
the relevant parts of the screen, all without doing a full
page reload. Our source material touches on a
simple example using a framework like Vue JS.
What's the key take away from that regarding MVC concepts in
the SPA world? What's really interesting is how
Spas, even if not explicitly called MVC framework, sometimes
implicitly follow a very similar architectural pattern.
In that Vue JS example, the interface components handling
both the presentation view and user input controller functions
are largely implemented within the HTML templates and
associated JavaScript components that manage that specific piece
of UI and the model holding the application state.
That dynamic data that's typically managed within plain
JavaScript objects or data structures within the SP as
code. So the separation is still
there, just implemented with different web technologies.
Precisely, and there's a specific feature often found in
these SPA frameworks that really makes this connection work
smoothly. You're talking about data
binding. Exactly.
Often two way data binding frameworks like Vue JS, Angular,
React handle this in different ways, but the core idea is
powerful. They provide mechanisms to
automatically synchronize data between your model, your
JavaScript data and your view what's shown on the screen.
So if a value changes in your model, the framework
automatically updates the relevant part of the UI.
And often if the user changes something in the UI, like typing
in a form field, that change can be automatically reflected back
into the model data. It really simplifies keeping the
UI in the application state In Sync.
So from small talk G wise through web frameworks to modern
SP as these core ideas of separating data presentation and
control logic have proven incredibly resilient and
adaptable. They really have the specific
implementation details change with technology, but that
fundamental principle of separation of concerns remains
incredibly valuable. And that brings us pretty much
to the end of this deep dive into MVC architecture, from its
pioneering roots way back in small talk, right through to its
modern adaptations in web framework works and these
sophisticated single page applications.
We really hope this gave you a clearer picture of this
foundational yet everevolving concept in software design.
Yeah. Thanks for joining us for this
exploration.