I´m planing a shopsystem. I want to sell different lamps. For that reason I have created a basemodelclass with properties which every lamp has and inherit from that class to special lampmodels. Now I want a controller to create productoffers but how can i do this? Do i need for every lampmodel a controller / view or is there a way to have one controller/view that can create me all kind of lamp?
I have read about 'ModelBinders' and think this could be a solution but I have no idea how this could work. A small example would be nice :-)
Have solved it and posted it in another question: stackoverflow
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I have doubts whether every view should have its own ViewModel or should I pass the plain model where there is no need for ViewModel? (What concerns me is that if I start to mix these two concepts, then I will end up with jungle later on)
I tried to google it but no one talks about that, every post I run into just explains the purpose of ViewModel and I know that the main purpose of ViewModel is so you can pass multiple models to view.
It depends.
In many use cases the main purpose is not to expose fields to being bound on form submission that the user shouldn't be able to update. I wouldn't slavishly create them when not needed but it depends on the developers and their level of understanding on when and why you use viewmodels vs domain/ef models. Also application code base size makes a difference.
Maybe you need select lists, maybe you want to convert some properties to different types. Lots of reasons to use them. However it is more code and mapping code even if you use a tool like AutoMapper. So they cost time to implement but maybe they fix problems and save other time? Maybe they fix a security problem? Maybe doing them all the as view models helps juniors understand? Maybe you would rather do the setup of a viewmodel at start than convert code later when it is really needed?
Consistency can help but doing a bunch of extra work may not be worthwhile. Best practice for me isn't best practice for you.
Consider the costs and benefits for your project and team . E.g. maybe your project is internal and no one is going to try to hack via adding data to submission
There are couple of reason to choose ViewModel over DomainModel.
1) First thing first is the security. Imagin you have a view for changing the password. If you pass the domain model to the view. probably you are exposing a lot of properties which is not necessary and it may cause a security problem. There is no reason to expose properties like LastLoginDate, IsActive, IsEnabled, NumberOfFailedLogin and so on for just changing the password.
2) The second reason is reducing logic from the view. If you pass a Domain class to the view, Possibly you need to add some extra logic for hiding extra properties or shape it as you like or adding logic based on the route and etc.
3) Because of the architecture. Exposing domain model to the view cause tightly coupling between your presentation layer and domain model which is not good at all.
We have been using ExtJs for a long time, and now, with the advent of MVC pattern in it we are facing a critical question of whether to use it or not in the times ahead given the approach we had been following so far.
In our application, we have similar screens, like 40 similar screens for generating the reports and so on. These report screens would be having a form with buttons - PDF, CSV, EXCEL. All the buttons would be having same functionality at every screen, that is, submit the form to a url and generate the specific report.
The approach which we had been following was to create a custom class, say reportscreen class, which extends the window class of ExtJs.
This custom report screen class would already have buttons with their handlers defined (given the fact that the functionality is similar for them for all the screens) and will also have a form present with a function setFormItems(). Any instance of this class would provide the items for the form using setFormItems() and the url for generating the report.
This approach not only helps us in reducing the development effort to a great extent, but also allows even a new member of the team to use the class & create a new screen.
Now comes in MVC, the most advised pattern, and the approach shared above is definitely not as per MVC pattern. But then, do we need to really move to MVC pattern here?
Using the above approach, we are not only able to save the effort, but also have a greater control over things.
The purpose of asking this questions is to know about the exact advantages we shall get if we implement the above scenario using MVC pattern and move away from our current approach.
Thus, what extra things would MVC bring to the table in the context above? And also, what would be the best way to implement such a thing in MVC pattern?
Thanks for any help in advance.
Do you need to use MVC? No. Assuming you've already got a structure that works well for you, if it's not broke, don't fix it. If you were starting a new project I'd recommend using MVC, but I wouldn't refactor a whole bunch of code for the sake of it. If you did use MVC, you would follow a similar approach. You'd have a base view class where you dynamically push on the items in the subclass. You'd have a base controller to handle all the custom events, then subclass controllers to implement custom functionality on a "per module" basis.
It's hard to explain the advantages of using MVC to someone who had no experience with it. As someone who developed with both ExtJs 3 and 4 (with MVC), I think one of the greatest advantages of MVC is that it forces you to think right - whether you want it or not, using MVC is likely to result in code base that is more reusable and better encapsulated. But if you boys and girls are good programmers/designers, this will be the case anyway.
If you do choose to move to MVC, I believe that the main change will be in that now instead of handling user interaction within your custom class, you will have a single controller to do the same job - leaving your custom class to realize the view only. Controllers in ExtJs4 are global - meaning that the same controller may control 40 similar views. So no duplication of controllers here.
It's important to mention that even within an MVC design you will find non-MVC code. For example, I have a custom record editor which is a form - the component knows how to handle user actions and update the records accordingly (the form is not submitted as it's mostly dealing with associations). This component takes the equivalent role of both the controller and the view within an MVC design. It seems to me more than reasonable to encapsulate things this way, rather than split this to a view and a controller. But the (non-reusable) user screens are implemented using MVC. So maybe just another reason not to rush to MVC.
While I agree with Evan that if it aint broken don't fix it, had I been your development leader and given time and money is not an issue, I would actually request the gradual migration to MVC - overall I think that 3 years down the line you won't regret this decision. I would at least attempt it.
When ExtJs 4 came out I scraped 2 months of work to rewrite from scratch a system using MVC - I don't regret this for a second now (I did at the beginning, but not for MVC - rather for the amount of bugs in the early versions of 4).
I have some weeks since im using CI, but now I've found some problems about the structure of my project, I would like someone to give me some clues because I am kinda stuck, the problem is this:
I have my project MVC, so, I am dividing it into files (each per functionality) for example, there is a file with all the functions corresponding at login, and other with all related at post (it's an example), but now I am on a moment where I need to use login or posting into another part of the project, reading I found out i cannot call a controller from another, I can use the helper but still I will need to use a model, so I have to take that code and paste it into the controller where I'm calling the model and so on (and it's not good), I found out I can use modules, still I don't want to go over them until someone could give me an experience of this, i wouldnt like to change the project, is any way I could run all those controllers (i know i can use run:: I'm not sure if i can send parameters in it), any ideas please?
Thanks in advance.
Fair warning, this type of question will get shot down by many SO moderators, but I'll give you some tips regardless:
Controller actions are single-use. If you find yourself with duplicate code in multiple controllers (or, needing to call a controller function from another controller), that's a sure sign you should move that code to a model or library.
Models are object-specific, not action-specific. I wouldn't have a model dedicated to logins, unless you have multiple types of logins (most apps/sites just have member logins, but you might have administrators, etc. that are stored in a different table from the rest). Instead, have a User_model class, and make function login($email, $password) a method of that class.
Controller-to-model interaction should be very concise. If you find yourself with 30 lines of code passing data back and forth between the same controller and model, you might be trying to do too much with that one controller action.
Keep your models fat, controllers skinny, and views dumb.
What is the best way to create logs & history in CakePHP. I was thinking if there is a way to create a Helper "that accesses" one table and then I call this helper inside of each controller that I want. However, I have read that this is not MVC standard. How would it be the correct way to do that?
I appreciate your time spent answering me that. Thanks!
thats what behaviors are for.
I use the LoggableBehavior from here:
https://github.com/alkemann/CakePHP-Assets/blob/master/models/behaviors/logable.php
works like a charm. they are then fetched and displayed in the view, if you want to.
Just implement a different log engine for that purpose. The CakeLog class actually works somewhat like an observer and the log engines like listeners.
Simply use CakeLog::write() and your custom engine that could load your log model in the constructor using ClassRegistry::init() and pass the incoming data from write() to the model.
The manual will help you with that. http://book.cakephp.org/2.0/en/core-libraries/logging.html#creating-and-configuring-log-streams
If I need two modes in my application what design pattern would I use so I can prevent ugly conditional code? App is currently MVC, but I don't want conditional code in my controllers and don't want two controllers for each view unless I have to.
Any suggestions?
A different subclass for each implementation, with shared functionality either in a common superclass or using the Template Method pattern.
Perhaps the State Pattern?
Abstract Factory, or Proxy. Your controller would contain some kind of Factory or Proxy instance that is used to retrieve a "mode" and act on it accordingly.
It is difficult to say for sure without more information, but I would suggest the strategy pattern. You could use the same controller and just swap out the strategy object to produce the desired change in behavior.
Here is an article you may find useful:
http://www.javaworld.com/javaworld/jw-04-2002/jw-0426-designpatterns.html
take a look at JSR-168, java portlet and its reference implementation, it should be similar to what you are trying to achieve.
The appropriate place for such a decision is the controller of MVC. I would recommend you write it there first. If it really is repetitive, it may be straightforward to figure out how to clean it up: you can move the conditional logic into a base class, or depending on the language, may be able to handle it with some sort of filter. You may also be able to create some "factory" for the views, which understands the "mode" of your application. Architecturally, though, all this is in the controller.
You are right to not want it in the view. This would be pretty messy. You probably want two versions of the views, one for "view" and one for "edit".
In the end, this is what controllers are for. Good luck!
In CafeTownsend demo made with PureMVC there is a similar situation where there are two different views and two separate Mediators. You absolute don't need conditional code for that. I don't know what technology and programming language you are using, but in Flex it will be a ViewStack with the ListView and EditView as children:
Corresponding mediator is registered by demand when the view is created. You can check other implementations using previous link.