I'm kind of new to the whole MVC concept, since I just recently started developing a web site using CakePHP framework. Therefore I turn to you asking for how to achieve the following in a best-practice-way.
I want to be able to place a number of pictures in a directory, which then is scanned for all filenames in it. These filenames should afterwards be passed to an arbitrary view, which then loops through all filenames making img tags of them.
It would be nice if this could be done in a general way, so that I could reuse the code for same task but with a different directory name.
I have already tried the following two approaches. Nevertheless, non of these felt like the best way to do it, for some reason.
Create a model with $useTable=false.
Create an ordinary class and import it as a vendor.
What is the best way to achieve what I describe above?
I'm thinking your original idea is the better one, use the Model to traverse/read/write the directory. Think of the File structure as your data source. You can pass the dirname to the model with $this->data and then let it use the File class to retrieve what you need. This would make it portable across Controllers (with loadModel())
Later on down the road if you move your image paths into a DB you only have to re-write the model to take that into account.
I've done the following before: create an e.g ImageManager class and pass it as an IImageManager to the constructor of your e.g ImageController instead of passing a repository. The ImageManager could then do all the work that you mentioned.
EDIT: I did that in .net mvc and don't have experience of CakePHP, but I guess there's a place where you can register the concrete implementation of IImageManager as ImageManager so the framework would know what to pass to the controller's constructor
I would create a helper for this purpose.
Edit: And for trawling through the filesystem use the Folder class from within your helper.
Related
I've been trying to implement a Front Controller on a VBScript (ASP Classic) based system for a couple of days. I come from a ASP.NET MVC and Java background, where MVC implementations are kind common and mostly done by existing frameworks. On VBScript, however, there's almost nothing done in this area, so it is the reason why I'm trying to do it by myself. I used this and this article as a guide on how to implement it.
I believed at first that I'd need to define some constant parameters for each request, so I created 3:
class_command 'which command responsible to execute the correct class handler
action 'which method of the class handler to execute
action_params 'which parameters the action will need
Next, I defined a generic controller handler for treating the request:
Public Function Controller_Handler(action_params)
Its task is to extract the constant parameters (class_command, action, action_params) and treat any errors (I'll add later a filter to process it) that might come like absence of the constant parameters or authentication problems.
But soon I realized a problem: how will the handler know which command to call, since the request is a string? I can't simply converting it to class using reflection, because VBScript (I think) doesn't have a reflection library or built-in feature.
So I thought I could create a Switch Case like this:
Select action_Params.Item("action_params")
Case "command_A"
' Call Command A
Case "command_B"
' Call Command_B
.
.
.
Case "Command_X"
' And so on
End Select
But that would kinda procedural way to do it. Next I thought of creating a XML file which would map all the commands and other stuff.
So my question is: is this a good way of implementing a Front Controlller pattern, considering VBScript limitations? If not, could you provide a guidance (hopefully with some example, even a simple one) on how can I do it?
Moving from classic to .net/mvc I can share what I did in classic asp to try to emulate this behavior as closely as possible without making it too much of a maintenance issue.
Using URL Rewrite in IIS are my routes. I usually just make one route and direct/rewrite all inbound requests to one controller.asp page to simplify things and not have a bunch of rules and controller redirects directly in my URL Rewrite settings for maintaining it easier (for me).
Using Request.ServerVariables("HTTP_X-ORIGINAL-URL") in controllers.asp you can grab the actual URL that was entered, which return something like.. /real/url
In controllers.asp programatically call the view based on the entered url using Server.Execute("view1.asp")
I have one class file called routes.asp that is included in each model/class file, and helps me gather the URL properties oRoute.GetPath_FirstDirectory() and so on. The model/class file then uses this data to create its property values that can be consumed by the view. Using CLASS_INITIALIZE in each model/class to populate itself from the route/url, or it could also be done directly in the view.
In the respective view I include my class/model file (if even needed) using <!--#include file="class.asp"--> then simply open Set Model = new cModelClass to initialize and start using it in the view. I don't include the class in the controllers.asp because the view will not inherit any of the variables from controllers.asp when using Server.Execute() to the view. So I include it directly in the view.
Error handling can be at multiple levels here, but ideally its in the controllers.asp. Specific error handling is usually at the actual model/class CLASS_INITIALIZE to avoid redundant use of the class in the controller, since it's already going to be initialized in the view.
Now this is not exactly what goes in in .Net mvc, but it's the best way I've come up with, and easiest to maintain for me. Maybe others have other implementations, but this is mine and solely based on my experience. And so far, it's been working out pretty well.
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.
using CodeIgniter normally one has to specify the controllers in the config/routes.php file.
This is not to handy, so I would like to be able to do something like this in a controller.
get url parts and check if the first part is specified in an array
if so, load the specified controller, if not, load default controller.
It basically mimics the behavior of the routes file, but there is no need to specify the wildcards before. I am using a base controller I extend with every controller, but I would like to have this controller just load (or include) the needed controller.
Does anyone have any idea how I can do this in a good way?
Thanks in advance.
// Edit
Okay, so here is my scenario.
I have cms and users can choose to include modules (e.g. a gallery).
I need to inlcude all the gallery php scripts without having to have "gallery" in the url.
I figured it would work if I use a "main controller" which loads another controller depending on the modules chosen. I realize this might not be the best way, so if there is a "clean" way to do it, please tell me.
As far as I know models are just for database stuff, so putting a whole gallery in there is not right either. The Plugin itself will of course be a library, but there is going to be some code to load the libs depending on the demands, get the database data, etc.
Thanks
The way you're doing this is incorrect. You never should take over the routing function to do this. What you need is to use some kind of module functionality to include the required methods and models; a module doesn't require to have route-accessible methods, so it's basically a "library" with a model and views.
If I remember correctly there are several plugins that provide this, One was HMVC (google it).
The ideal form would be to load the "Module" on demand from your controller, like you do with the core CodeIgniter Libraries; so lets say you're inside the blog controller action and you want to include the comment module which is used on gallery and on images, you just include the module and call it's methods to get the data which you can then pass to the view as needed; you can even render partials and store them into a variable to pass to your master controller.
Hope this is enough to get you on the right track :)
I may be misunderstanding your question but you want to load your controllers if you go to them and if not you want to go to your default.
If I am understanding correctly you can do a couple things in your routes have a route that takes everything to your default controller.
In your controller have an array of all your controllers then implode the array to a regular expression
$array = [c1, c2, c3, c4];
$str = implode('|', $array);
$regex = "($str)"
now just add your regex to a route
now redirect as you see fit.
But this is really what the routes file is for you you are just dancing around something that should be used.
I'm working on a joomla component that includes building a schedule. On any given day it needs to look at a set of rules (day of the week, date of the year, type of event) and return all of the possible start times. It would make sense to have a class that calculates these things, but I'm not sure it fits in the model or controller (and certainly not view) categories. Am I supposed to create a com_myproject/lib (or similar name) and have joomla auto-load the classes?
I'm new to joomla and started with the framework/project provided at http://docs.joomla.org/Building_Joomla_Extensions_with_Apache_Ant.
You should create a helper class. Have a look here for an example, albeit it is for a module, but the same concept applies.
You might want to start off with Developing a Model-View-Controller Component - Part 1 tutorial and work your way through that by hand. Using Apache Ant to learn how write an extension is like taking a canon to shoot fish in the barrel. It can be done but probably not the best way of doing it.
The Joomla! MVC pattern is very peculiar and difficult to understand. I don't quite understand it myself. I was advised on the developer email list to look at how other components are put together. Guess what? All the other developers do it differently, with some of the bigger components looking like spaghetti code in their organization.
The bulk of your component code should be in the controller, either as part of the controller class or a separate class file that's imported in. You don't need a separate library directory unless you're working on a big component with multiple class files. This Joomla! thread might be applicable.
After developing in CodeIgniter for awhile, I find it difficult to make decisions when to create a custom library and when to create a custom helper.
I do understand that both allow having business logic in it and are reusable across the framework (calling from different controller etc.)
But I strongly believe that the fact that CI core developers are separating libraries from helpers, there has to be a reason behind it and I guess, this is the reason waiting for me to discover and get enlightened.
CI developers out there, pls advise.
i think it's better to include an example.
I could have a
class notification_lib {
function set_message() { /*...*/}
function get_message() {/*...*/}
function update_message() {/*...*/}
}
Alternatively, i could also include all the functions into a helper.
In a notification_helper.php file, i will include set_message(), get_message(), update_message()..
Where either way, it still can be reused. So this got me thinking about the decision making point about when exactly do we create a library and a helper particularly in CI.
In a normal (framework-less) php app, the choice is clear as there is no helper, you will just need to create a library in order to reuse codes. But here, in CI, I would like to understand the core developers seperation of libraries and helpers
Well the choice comes down to set of functions or class. The choice is almost the same as a instance class verses a static class.
If you have just a simply group of functions then you only need to make a group of functions. If these group of functions share a lot of data, then you need to make a class that has an instance to store this data in between the method (class function) calls.
Do you have many public or private properties to store relating to your notification messages?
If you use a class, you could set multiple messages through the system then get_messages() could return a private array of messages. That would make it perfect for being a library.
There is a question I ask myself when deciding this that I think will help you as well. The question is: Am I providing a feature to my framework or am I consolidating?
If you have a feature that you are adding to your framework, then you'll want to create a library for that. Form validation, for example, is a feature that you are adding to a framework. Even though you can do form validation without this library, you're creating a standard system for validation which is a feature.
However, there is also a form helper which helps you create the HTML of forms. The big difference from the form validation library is that the form helper isn't creating a new feature, its just a set of related functions that help you write the HTML of forms properly.
Hopefully this differentiation will help you as it has me.
First of all, you should be sure that you understand the difference between CI library and helper class. Helper class is anything that helps any pre-made thing such as array, string, uri, etc; they are there and PHP already provides functions for them but you still create a helper to add more functionality to them.
On the other hand, library can be anything like something you are creating for the first time, any solution which might not be necessarily already out there.
Once you understand this difference fully, taking decision must not be that difficult.
Helper contains a group of functions to help you do a particular task.
Available helpers in CI
Libraries usually contain non-CI specific functionality. Like an image library. Something which is portable between applications.
Available libraries in CI
Source link
If someone ask me what the way you follow when time comes to create Helpers or Libraries.
I think these differences:
Class : In a nutshell, a Class is a blueprint for an object. And an object encapsulates conceptually related State and Responsibility of something in your Application and usually offers an programming interface with which to interact with these. This fosters code reuse and improves maintainability.
Functions : A function is a piece of code which takes one more input in the form of parameter and does some processing and returns a value. You already have seen many functions like fopen() and fread() etc. They are built-in functions but PHP gives you option to create your own functions as well.
So go for Class i.e. libraries if any one point matches
global variable need to use in two or more functions or even one, I hate using Global keyword
default initialization as per each time call or load
some tasks are private to entity not publicly open, think of functions never have public modifiers why?
function to function dependencies i.e. tasks are separated but two or more tasks needs it. Think of validate_email check only for email sending script for to,cc,bcc,etc. all of these needs validate_email.
And Lastly not least all related tasks i.e. functions should be placed in single object or file, it's easier for reference and remembrance.
For Helpers : any point which not matches with libraries
Personally I use libraries for big things, say an FTP-library I built that is a lot faster than CodeIgniters shipped library. This is a class with a lot of methods that share data with each other.
I use helpers for smaller tasks that are not related to a lot of other functionality. Small functions like decorating strings might be an example. Or copying a directory recursively to another location.