I have seen this question What is the difference between a class library and a framework
and throughout all the provided answers, the framework is always referenced as a framework. I am looking to get more technical. What exactly is a framework? A class of classes that control all functionality and provide ultimate abstraction and the ability to customize it? I am just looking to understand what exactly a framework is, as far as initializing it, not just what it accomplishes, but how exactly it is implemented. How I believe it's used/implemented is listed below.
variable = Framework() -> Reference the variable
Framework is an infrastructure, ready-made and predefined, with some particular rules of the game on the "development field", according to which, you can build your application, on top of it, by "playing with framework rules" (you can, at some extent, customize those rules).
Spring MVC is a good example of Framework. You don't control how the View Resolving, Dispatching or Template Rendering happen and achieve a goal together.
Think of this as a big machine, where you can plug in and integrate your components which are applicable to that machine.
Library, on the other hand, is just a set of classes, which provide already implemented functionality out of the box, in order to not start inventing the bicycle again and again.
Apache Commons is a good example of the Library. It has a lot of ready tools and functionality to facilitate your work with String objects.
Think of this as a set of instruments and tools, using which, you can build your own machine.
With respect to how it is implemented question. This is like asking how the Boeing A220 is built?. I'm not sure anyone can describe here how the Framework is implemented in the details. But if I understood uour point about whether the Framework is used via classes, then:
Framework might provide some classes as an abstraction, yes, but it's not about them, it's more about mechanics of the entire system. The main thing it provides is the mechanism and mechanics of how the system is designed to work.
I'm asking why people are always choosing MVVM for using Xamarin on a cross-platform.
Did you think MVVM will share more code than others patterns?
Thanks for reply
IMMO and more like an (philosophical?) opinion than an answer.
I Think:
Its more about separation of concerns, scalability, than to write less code(It could be quite verbose in c# ), Perhaps the code sharing will be more like functionality sharing when it helps to reuse modules/components/ ViewModels ...into Multiple views? ...different VM for single Models or Entities ?.
... its also the de facto mv* pattern for client side .net (as in XAML). and used by MvvmCross (Quite popular cross platform framework). Nothing stops you trying to use another pattern (sometimes is quite difficult to tell what pattern are you following once you are deep down in the application life cycle)
...but as I mentioned before is the "Pattern of choice for .Net UI Bindings"...the knowledge base is extensive(I think this is the key) ...so ...easy to follow and/or helpful to get back on track when things start to get untidy (as in Jenga-Code , Spaghetti, etc )
... Said that Mvc pattern is also a another choice ...check Moncross, also widely used in .net , but usually on the server side ...extensive knowledge base ...an applications ..that you possibly might need to extrapolate into your client side needs due to its backend origins?
Check another languages and frameworks like jscript/java/scala etc... you could use any pattern mvp/mvc/mv*whatever* but particular frameworks are prone to follow a particular pattern ( is this a pattern?).
Perhaps because language-framework's pioneers and big brains have stepped down that route and showed what can be done ...then we gladly follow their findings and advice .. .
I am thinking about developing a new application using web toolkit. I decided that the best option is going to be to use the Model-View-Presenter Design Pattern. After doing plenty of research, I found two different ways of implementing the skeleton code. (I am still trying to learn MVP and how to best utilize the disjunction between the model and the view)
Here are the two links discussing GWT MVP
https://developers.google.com/web-toolkit/doc/latest/DevGuideMvpActivitiesAndPlaces
https://developers.google.com/web-toolkit/articles/mvp-architecture
I read through and understand all the information in the second link, how you associate presenters with views, and how you have your custom events and such. I really like this because this means that several developers will be able to work on the project I have in mind.
However, the first link, also points out some interesting stuff, mostly using XML and #UiBinder and other things. I feel that those will not be necessary for this particular application but I want to make sure I have not overlooked anything.
Basically - How good of a programming practice is the style the style in the second link (the one with presenters for each view)
Thank you
You should be not be comparing MVPActivitiesAndPlaces and MVP . If browser history management is not your concern use only MVP.
Activities And Places are not mandatory for MVP. They only allow you clean browser history management which integrates nicely with MVP architecture.
UiBinder is not mandatory for MVP. They can be used with MVP.
The MVP design paradigm mostly is driven with Unit testing as main driver and to keep out slow running GWTTestCase out as much as possible.
At the heart of this pattern is the separation of functionality into
components that logically make sense, but in the case of GWT there is
a clear focus on making the view as simple as possible in order to
minimize our reliance on GWTTestCase and reduce the overall time spent
running tests.
I've decided to dabble a bit in MonoDroid and MonoTouch and port one of my WP7 apps as a starter. I would really like to reuse my existing ViewModels but since both Android and iOS seem to have no such thing as XAML's strong databinding I would like to ask if anyone went that route before and can recommend some best practices or existing solutions.
We're doing this with an application right now, but writing for iOS first (even before Windows). It is not full of rainbows and ponies for sure.
I would recommend the following:
Use a MVVM framework on Windows that doesn't require you to expose ICommand on every action the user takes (like Caliburn, for example), it also shouldn't require a dependency to it from within all of your ViewModels.
Conditionally inherit the WPF-specific pieces of your ViewModelBase class, you can do this with partial classes or an #if iPhone directive. INotifyPropertyChanged or ICommand are examples.
Use an IoC container, it is very helpful to abstract out things like saving settings to the filesystem which will be very different on all platforms. Also helps to sort out your dependencies as well, which is very helpful for separating out platform-specific code from non-platform specific.
Use a "messenger" of some kind (example here), usually included with an MVVM framework. This is a must in my opinion, at least for iOS. Apple's MVC is so all over the place, it's better to have global messages you can subscribe to in a weak referenced (and decoupled) way.
Use MVC on each platform like you would natively, then treat each ViewModel as you would if you were calling it manually. There are no UI bindings, no ICommand, so keep your ViewModel's simple.
Linking files is the best trick ever. You don't want a copy of each view model per platform, so make sure you know how to link to a file within projects in Visual Studio and MonoDevelop. This also makes #if iPhone and #if Android statements possible.
I know you are working with an existing application, so it's tough. It may be simpler to just reuse your business model and that's it. Android and iOS have MVC patterns of their own, and are drastically different from WPF. You might also only need a subset of each ViewModel on mobile devices, which could make it easier to just rewrite.
In our case:
We're using TinyIoC (also has it's own messenger)
We will use Caliburn-Micro when we start on WPF, we don't need some of the features in full Caliburn
I've recently finished a large project which we wrote wp7 first, and which was then ported into touch and droid.
As part of this we've released our own mvvm framework - including some databinding support for touch and droid - the source is available at http://github.com/slodge/mvvmcross
The experience of porting to droid was good - the axml layout files provided a good hook for databinding. Currently, however, i'm not quite as happy with the binding we achieved for touch - although montouch.dialog does at least provide us with some nice looking code sometimes.
I realize that this may be subjective but I truly need an answer to this and I can't seem to find anything close enough to it in the rest of the Forum. I have read some folks say that the framework (any MVC framework) can obscure too many things while others say that it can promote good practices. I realize that frameworks are great for a certain level of programmer but what about individuals starting out? Should one just focus on the language or learn them together?
I think web development is way more than anyone grasps when they first start getting into it! Read this and know that it is all optional...but required to be really good at what you do.
I suggest that you spend time learning your language first. I would suggest learning C# simply because it is vastly more marketable and it is usually directly supported in most of MS products. By learning C# - programming in ASP.NET, console apps, servers, services, desktop apps, etc. will all be within your reach. You can program for most of the MS products as well as on many Linux type platforms.
Once you have this down then you can move to programming for the web as programming for the web has some intricacies that most other environments don't have. Concepts such as sessions, caching, state management, cross site scripting, styling, client side vs server side programming, browser support, how HTTP works, get vs post, how a form works, cookies, etc. are all at the top of the list of things to learn separately not to mention learning the ASP.NET base frameworks and namespaces.
Once you have the programming language down and then the concepts of web programming I suggest that you pause and learn database design. Don't worry about performance just yet...try to first learn good design. Performance will come next. A good start for you is Access (blasphemy I know). It is easy for a beginner to work with. And it translates into a more robust platform such as SQL Server easily. Learn at the very least some SQL...but I suggest that you learn as much as your stomach can handle. I heard someone say that SQL is like the assembly language of the database. The number one thing that slows an application to a halt is piss poor database design and poor queries. Once you have this knowledge - stuff it away in the back of your mind and take a look at a good ORM. NHybernate is probably best at the moment but is more complex that the basic learner needs. For that reason I currently suggest getting LINQ to SQL up and running as it is SUPER EASY to work with. Then look at Entity Framework (although I still think it sucks...and you should wait till EF 2.0...ERRRRR...now 4.0 released with .net 4.0). Then NHybernate.
Now is the time to start to understand the infrastructure that is required by web development. You may bump your head against this as you learn some of the web programming stuff. But you need to understand the basics of DNS, IIS, load balancers, sticky routing, round robin, clustering, fault tolerance, server hardware setup, web farms, cache farms (MemCached Win32, Velocity), SMTP, MSMQ, database mail queuing, etc. Many people may say you don't need this. That there will be some knowledgeable network admin to help you out here. However they generally know things that impact them...not you. The more you know here the more valuable you will be to the company that hires you.
Now you can get into the details of best practices and design patterns. Learn about the basics such as repository pattern, factory pattern, facade pattern, model view presenter pattern, model view controller pattern, observer pattern, and various other things. Follow Martin Fowler and others for suggestions here. Take a look at concepts such as inversion of control, dependency injection, SOLID principle, DRY, FIT, test driven design, and domain driven design, etc. Learn as much as you can here before moving to the next step.
NOW you can think about frameworks! Start by creating a basic application with ASP Classic (comes with IIS for free!). This will give you a flavor of a no frills web development environment. Take a look at ASP.NET web forms (briefly) to see how MS attempted to make things easier by hiding all the complex stuff (which you now know how to manage on your own from your readings of the above materials!!!). Now you no longer need ASP.NET Web Forms. Move immediately to ASP.NET MVC. The MVC framwork gives you all the power you need to create a good easily manageable web application. If you build something really big no framework for pure web development may be able to deal with what you need. However MVC is way more extensible for such UBER custom scenarios.
Now that you have made it through the journey to ASP.NET MVC you can take a look at things such as Microsofts Enterprise Application Blocks (such as they use at MySpace). Take a look at Elmah error logging (a must have). Look at how to build a custom SiteMapProvider for your MVC site. If you need to get into searching stuff understand Lucene.NET.
And if you made it this far...you are ready to figure out the rest on your own as it comes up! Have fun. There is a lot of room in this space for a person with some understanding of all of the above concepts.
You'll be using SOME sort of framework. The question is, what level do you want to learn at?
You'll probably not care to learn about asynchronous I/O and mutlithreaded vs. select/poll styles of web servers.
So then, your language of choice is going to provide a layer atop this, the languages preferred "web interface" API. For Java it's Servlets, the lowest level you'd typically code at for server side web applications.
You should find what this "lower level" layer is in your language and learn the API at least. You should know basic HTTP like status codes, cookies, redirects, POST vs GET, URL encoding, and possibly what some of the more important headers do.
You'll then come to appreciate what these higher level frameworks bring to the table, and be better able to evaluate what is the appropriate level of abstraction for your needs/project.
Web development requires a certain degree of organization, since it relies so much on separation of concerns. The browser, for example, is designed to display data and interact with the user. It is not designed to lookup data from a database, or perform analysis. Consequently, a web development framework can help provide services that are needed to make the browser experience a practical one.
The nice thing about employing a platform is that it will provide core components essential to the making of any web application that you won't (and shouldn't) have to think about, such as user membership, for example. Many of the design decisions and deep thinking about how to implement these services has already been done for you, freeing you to focus on what you actually want you application to do.
Of the available frameworks, I find that frameworks that implement the MVC (model-view-controller) pattern are very practical. They clearly organize different functions of web development, while giving you full control over the markup presented to the browser.
All that said, you will need some fundamental skills to fully realize web development, such as HTML, CSS, and a core programming language for the actual underlying program, whether you use a platform or not.
I don't think I agree with the Andrew. I don't think learning C is a pre requisite for web development. In fact, learning something like Javascript, Action-script or PHP is often easier due in large part to the vast numbers of sites and tutorials available, and are enough to expose you to the fundamentals of pretty much every programing language. Variable, Conditions, Loops and OOP. I just think learning C# introduces a lot of learning that isn't really relevant to web development such as pointers and memory management.
As for wether you should learn a framework first? Definitely not. Never ever. You need to be able to stand on your own two feet first and be comfortable with HTML/CSS, Server Side Scripting (PHP/ASP/Python/Ruby whatever) and love it or loathe it, but you're going to have to have a decent understanding of Flash and Action-script.
The order in which you learn these is entirely up to you. But my learning plan would go like this...
Start with HTML. It takes about half an hour to get the basics (it's made up of tags with attributes, end of lesson 1) and it's good to get it out of the way first.
Then start leaning CSS. You'll get the basics again, very quickly. But CSS is a minefield so expect to spend the rest of your life figuring it out.
Next up Action-script. Most people wouldn't agree with me, but bear with me. HTML and CSS aren't programming languages. Action-script is. And learning a programing language for the first time is difficult and tedious. The advantage Action-script has over most other languages is that the results are very visual. It's enjoyable to work with and you can sit back and take pride in your accomplishments at regular intervals. This isn't possible with server-side scripting languages or Javascript and there's a whole host of stuff you need to learn to get server side scripting up and running. You can't build space invaders in with PHP for example.
I've changed my thinking here. I would encourage beginners to ignore ActionScript and focus on Javascript. I still believe that being able to see stuff on screen quickly is a good motivator, but I would encourage people to look at canvas tag tutorials and frameworks. Javascript has come a long way since 2009, and is now the lingua franca of programming, so it's incredibly useful. My initial point about HTML and CSS not being programming languages still stands.
Then, you can start with your server side language. At the same time, you're going to have to figure out the database stuff. I recommend PHP and MySQL because it's free.
Again, I've changed my thinking here. I would encourage beginners to use Javascript on the backend (Node.js), and split their database learning between relational databases and noSql solutions such as Mongo.
Then.... learn your framework. Or better yet, roll your own. That's what I've been doing and it's supercharged my learning.
If you're getting into web development, You HAVE to know how those building blocks work. You don't have to be an expert in all the areas, but you should try to become an expert in at least one of them. If you start learning a framework before you get the fundamentals you'll be in a sticky middle ground where you don't understand why things don't work which will infuriate you, and anyone who has to work with you.
you should learn how to use framework because it would be helpfull for u in the future also it is easier to learn.
MVC will help you a lot .. trust me ... i was developing web project not using mvc and it is like mess ... (in the past there are no well know mvc and i never heard about it)
Short version: yes, and then some.
FWIW : This more generic answer may be of use to someone out there.
What: Frameworks take out tedium of using boiler-plate code again and again. They hide complexity and design issues under wizards and conventions. They also use special libraries, design patterns etc. in ways that are far from obvious to a beginner.
So using a framework is good for getting things done without knowing exactly how - like using an ATM without knowing the internals. You just add your code bits in certain places and things 'just work'.
HTML > CSS > Ruby > SQL > Rails/Javascript framework > Libraries would make for a good learning track. Rest you learn as you go along by being curious, hanging out on forums or as extended learning as need arises.
HOW: The problem starts the minute you step outside simple text-book examples (i.e. when you try to get it to do something even a bit different).
Decoding cryptic error messages when it seems like you've done everything right but things still don't work. Searching on error strings in forums may help out. Or just re-starting from scratch.
Reading up articles and books, videos, trial-and-error, hard-work, search-engines, stackoverflow/forums, local gurus, design articles, using libraries, source-code browsing are a good way to climb the learning curve gently and on a requirement basis.
Working-against-the-framework is the number one problem for beginners. Understanding what the framework expects is key to avoiding white-hair in this phase. Having enough insight to manually do what the framework automates may help reduce this second-guessing effort.
WHY: For more advanced debugging/design, it's good to know what the framework is doing under the hood esp. when things don't work as you planned. Initially you can take the help of local-gurus or forum gurus who've already done the hard work. Later as you go deeper you can take on more of that role. For example there's a "rebuilding rails" book which looks under the hood of Ruby on Rails.
Note: Some of the tips are oriented towards Ruby/Rails but you can easily substitute your favourite language/framework instead.