Basic on Codeigniter controller - codeigniter

I am new in codeigniter framework.I have some question.When we write some controller class then we call constructor.I am loading some library and some helper.I want to know what is the perfect way for loading this helper and library under construct class or under other functions.If i load everything in construct class then what is the disadvantages for it?if i use more controller class for one project then it is good or bad.Like i want to use some controller class for ajax functionalities,some for form submission,some for other sector.My english is not so good.Please help me.

For common libraries and helpers used by all functions of your controller try to load it in constructor or autoload. Except that for specific libraries e.g. payment gateway load inside the function.
How you use or how many controllers you are using depends upon your needs. But I would suggest you to build separate controllers for separate functions. Like admin for admin functions, users for user related functions, and so on. It build a user friendly URL too.

Well! everything depends on your requirements.
If you need any library , model or helper globally you can autoload it autoload.php.
It means the loading will be done on each request.
if you need any library , model or helper throughout your controller methods you can load them in constructor.
It means loading will be done on each method of controller.
if you need any library , model or helper for specific method you can load them in method.
It means loading will be done in method only.
For example let suppose you nees session and database library throughout your application so you can autoload it.
For a specific controller you need priviliges library so load it in constructor.
For email you need to send load email library in function.
These are only examples. You can explore SO to find more.

Loading takes time and performance. Not noticeable time by human standards, but time regardless. In order to cut of some slack to your server in the future, you do it a favor by only loading whatever is it you require for each page/controller method.
Used (almost) always
You can use application/config/autoload.php for things you almost always use. I usually include the helper url here.
Used (almost) always inside specific controller
Load it inside controller __construct. Don't forget to include parent::__construct();.
Used inside specific page
Load it inside method/function.
Used inside specific function
Load it at beginning or inside if-statement in function. You can load it numerous of times, it will only execute first time.

Related

Which is better in codeigniter? Adding a function in a helper or adding a function in an extended base class

In a codeigniter project i have to do some set of stuff in one than one controller.
I code all that stuff in a function and now i need to call whenever necessary.
i think Writing this function in more than one controller is not good.
i have 2 options,
create a helper and write these function in that and include the helper in necessary controllers.
Since i have extended CI base controller (My_Controller) and most of my controllers are extended that controller, i can write this function to my base controller also.
I have confused which one is better, right way?
Which one will speed up the process?
Is the second way slows the site?
They are identical for all intents and purposes.
Using a helper allows you to make the code portable, so you can use it in other projects, or to be called from anywhere in the code base, in the case of a formatting function for example
If you were planning to put it in a controller, then MY_Controller is best bet
Just to help you on you endeavor what i do is: (this is just me)
If i need to use something in the views, i use a helper a custom one or built in.
If i want to do something on a controller that other controller will be using too and don't want it to mess up or crowd my controller i use a library (pretty much you can use a helper but i chose to use a library)
If i want to load lets say a method, to affect Globally or some of the controller i use the base controller. (you could also use helper or library)
The key is you are not restricted to one, choose the best that suits you, as the saying goes, there are many ways to skin a cat, but please don't skin a cat..

yii writing a resuable code for cascade dropDownMenu

I wrote a three cascade dropDownLists that its listData are generated from the database models.
The lists are generated with an Ajax call to action in the controller based.
I want to reuse this code and to share it with more pages.
I tried to do the following:
Write it as a Custom Widget.
currently i use 'createurl' function that calls a function in the matching controller.
I cant write JavaScript since i want to use the existing db models.
In this case i need to write the action functions in an independent file - so should i write a controller? where should i place it?
Write it as a part of a module - but it seems overkill.
any suggestions, i am sure that there is a right and simple way to do it.
You could create it as a helper. A helper is just a class in the components which has no direct action in the M->C->V action flow but can be used in any controller, model, view, component, module, etc...
I would write a helper method to call it from the controller.
Another suggestion could be to extend CController to your own base controller and have your actual controllers, extend from your custom base controller. That way you can make it easily available in every controller, and then you just set some members that contain the models to use which you set in the actual controller.
If you need more help on this, find me on freenode #yii

CodeIgniter Model Call to Model

Im using CodeIgniter 2.0.2 and I noticed while calling a Model from within a Model, you dont need to load it.
For instance, in a Controller you need to write
$this->load->model('my_model');
$this->my_model->my_function();
But in a Model it can load just like this
$this->my_model->my_function();
Should i avoid writing my code like this, or is this safe?
I would avoid writing my code like this, but for a different reason.
Models are generally loaded from controllers, so it seems strange that you would need one model to call another one. Are you sure that there is not a better way to structure your code, such as having a model base class or using a helper for common functionality?

Codeigniter Dynamically load controller depending on url (outside routes.php)

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.

CodeIgniter: Decision making for creating of library & helper in CodeIgniter

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.

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