DEV Community: Kartik Bhat

Laravel for Beginners : a Quick Guide - 8

Kartik Bhat — Tue, 24 Aug 2021 15:55:42 +0000

Laravel Routes

I hope you understood the concept of adding data from user interface and receiving it response back to user interface,

Let's revisit concept of 'routes'...

what is 'route' ?

simply, route is a key word that connects user interface to the backend - Controller; :)

Ok in my previous articles you saw these kinds of routes ;

Route::get('addData', [DataController::class,'addData']);

right ?

(revisit web.php file and verify it once)

this will connect to addData() function present under DataController Class, correct ?

Hope you observed that you are using Route Object to define new route ;

this Route object is actually defined under this class (you can notice this at the top section of the file align with use keyword)

Illuminate\Support\Facades\Route;

then after that you observe key word get; it is nothing but HTTP method; yes exactly,

it will catch a type of request using a HTTP method that you used while calling that route,

HTTP method is a way request rises to the application's backend ;

What are different types of HTTP methods ?

GET
POST
PUT
PATCH
DELETE
OPTIONS

for a time being lets concentrate on GET and POST methods only, and these are the methods we frequently use in our laravel applications.

Laravel support all these kinds of methods; like

Route::get('addData', [DataController::class,'addData']);

Route::post('addData', [DataController::class,'addData']);

Route::put('addData', [DataController::class,'addData']);

Route::patch('addData', [DataController::class,'addData']);

Route::delete('addData', [DataController::class,'addData']);

Route::options('addData', [DataController::class,'addData']);

along with above mentioned HTTP method routes laravel also provides another route type, it is any , it catches any kind of HTTP method

Route::any('addData', [DataController::class,'addData']);

Mistyped routes/requests

laravel matches incoming requests HTTP method first, then it finds suitable route in web.php file, if it found then control moves to controller's method; else you can observe 404 page

let try this,
You know we have a route called,

Route::get('addData', [DataController::class,'addData']);

hit this route from browser; (hope you are running laravel app)

http://127.0.0.1:8000/addData

you can observe this

right ?

now just alter keyword addData to addData--1 present in the url; Ok

now hit that url again;
(Do verify that we don't have any route defined called addData--1 in our web.php file)

http://127.0.0.1:8000/addData--1

since we don't have any such route; laravel manages to load 404 page;

So, no need to worry about mistyped routes/requests from browser, laravel manages it by itself, seems interesting right ? :)

Routes and Form submit

whenever the form submit happens, some that will be passed to the backend from our user interface(say frontend), right ?

Open addData.blade.php file located under resources->views folder

<html>
    <body>
        <div>
            <h3>Add Data</h3>
            <form method="GET" action="{{ url('saveFormData') }}">
                <label>Name</label>
                <input type="text" name="name" />
                <label>Age</label>
                <input type="number" name="age" />
                <button type="submit">Save</button>
            </form>
        </div>
    </body>
</html>

you can observe method and action mentioned with form element

method - GET
action - route saveFormData

here form is submitting data to the route saveFormData via GET http method; you know it I suppose :)

Now open DataController class and go to the function returned by 'saveFormData' route; it is saveForm(), add dd() of $request after entering the function.

public function saveForm(Request $request) {
        dd($request);
        $data = [
            'name' => $request->name,
            'age' => $request->age
        ];
        $insertData = Data::create($data);

        if(isset($insertData['id'])) {
            $message = "Success";
        } else {
            $message = "Failed";
        }

        $response = [
            'message'=>$message
        ];

        return view('response',$response);
 }

Ok, then hit the route 'addData' from your browser;

http://127.0.0.1:8000/addData

then fill the form and submit;

You can see this window right ?
Now,, just observe URL bar;

you can see those form input data; those are passing as a url parameters to the backend(Controller); right ?

now, lets change form method from GET to POST present in the file addData.blade.php

<form method="POST" action="{{ url('saveFormData') }}">

Again, hit the addData route and fill the form ; then submit.

What you are seeing ?

this error right ?

Why ?

Observe web.php file; there is no route with a method post having keyword 'saveFormData' ; Observed ?

what you got ?
route catches an http method that request is coming from; through form you are sending data through POST method for 'saveFormData' route; it actually doesn't exist;

Route::get('saveFormData', [DataController::class,'saveForm']);

it is a get route with a key word 'saveFormData' , it doesn't catches request with POST method; then how to catch it ?

Simple, create a similar route with post method; like

Route::post('saveFormData', [DataController::class,'saveForm']);

that too returning same controller's same method; no issues.

now again hit the url : ####http://127.0.0.1:8000/addData####

and fill the form and submit again;

what you are seeing now ?

you are seeing dd() response of $request; right ?

Observe URL bar now; there is no url parameters exist but still Controller is receiving form data; right ?

This is what the main difference between GET and POST http methods :)

POST method doesn't shows form submitted data as an URL parameters where as GET method clearly shows;

There is a limitation of data length that can be passed through GET method, where POST method hasn't any such;

Even though both the method has there own features; primarily we can prefer form data should be submitted through POST method, a secure approach we believe;

While sending FORM data through POST we need add another constraint to the form i.e CSRF token (Cross-Site Request Forgery)
is a way our application identifies that request is coming / data is submitting from known/authenticated source, Laravel automatically generates this CSRF token and just we need to add it within our form element

within form element of the addData blade file we just need to mention

@csrf

<html>
    <body>
        <div>
            <h3>Add Data</h3>
            <form method="POST" action="{{ url('saveFormData') }}">
                @csrf
                <label>Name</label>
                <input type="text" name="name" />
                <label>Age</label>
                <input type="number" name="age" />
                <button type="submit">Save</button>
            </form>
        </div>
    </body>
</html>

it will be automatically verified by laravel while receiving the request at backend;

this is all about brief explanation on Laravel Routes; Hope you understood about it;

Bye ;)

Laravel for Beginners : a Quick Guide - 7

Kartik Bhat — Tue, 17 Aug 2021 00:01:24 +0000

I hope you understood concept of interaction between controller and user interface and how blades files can be used for user interface creation.

Let see, a simple user creation and sending data to controller then to model; flow,

Lets Begin,

first create a 'route' called addData,

Route::get('addData', [DataController::class,'addData']);

then, add addData() function in our DataController Class, it returns our blade file addData.blade.php; Ok

 public function addData() {
    return view('addData');
 }

create addData.blade.php file under resources->views folder,
and add this code to it

<html>
    <body>
        <div>
            <h3>Add Data</h3>
            <form method="GET" action="{{ url('saveFormData') }}">
                <label>Name</label>
                <input type="text" name="name" />
                <label>Age</label>
                <input type="number" name="age" />
                <button type="submit">Save</button>
            </form>
        </div>
    </body>
</html>

its just a simple HTML form right ?

form is of get method and it will be submitted to the route 'saveData' .

route can be referred using url() function inside our blade files. it then resolves full URL while loading a DOM.

Now hit 'addData' route from your browser; You can see this window,

right ?

inspect (right click ->inspect) this page and search for form element/tag, you can observe its action 'url'.

Now, create an another route 'saveData' that receives the form data submitted by addData blade file,

Route::get('saveFormData', [DataController::class,'saveForm']);

create saveForm() method in our DataController Class,
add these code to it;

public function saveForm(Request $request) {
   dd($request);
}

Observe, here our method can accept $request parameter of Request type, Laravel carries any request data in this Request Object,

to access this Request object , you need to use/add this instruction after namespace statement in our Class file, (exists by default add it if you can't find it)

use Illuminate\Http\Request;

then, in saveForm() method, I have mentioned dd($request); it shows request data on our screen, Ok

Fill out that form and hit save; you can see this right ?

Look into the request index; you can observe submitted data through form, under parameters array; Correct ?

it confirms that submitted data is reaching our controller;

Now, create an array that contains submitted 'name' and 'age' as its keys, in our saveForm() function. Using $request variable we can access those name and age; make dd() of that created array too,

public function saveForm(Request $request) {
    $data = [
        'name' => $request->name,
        'age' => $request->age
    ];
    dd($data);
}

fill out the form and save it again, you can see this window,

You are now done with creation of an array that is required to insert data into the databaserevisit if possible (in my one of the previous article you came across this ; but there you just added/hardcoded dummy data into the array; but now you are getting actual data from user interface)

add create statement to insert it into the database;

public function saveForm(Request $request) {
   $data = [
        'name' => $request->name,
        'age' => $request->age
   ];
   $insertData = Data::create($data);
}

$insertData holds insert status of the data(holds table inserted array/data), if it got successfully inserted then a sure $insertData contains a ky 'id' returned by database table;

Let's make its dd(), to confirm about it;

public function saveForm(Request $request) {
   $data = [
        'name' => $request->name,
        'age' => $request->age
   ];
   $insertData = Data::create($data);
   dd($insertData);
}

you can see this window after refreshing/reloading our browser page (form submits again),

attributes index holds the response status of the database create operation,

now, if the 'id' present in the response I need to show a response message on user interface; for that I will add a logic isset()

this will check whether prescribed data exist or not, returns a Boolean true or false,

if(isset($insertData['id'])) {
    $message = "Success";
} else {
    $message = "Failed";
}

$response = [
    'message'=>$message
];

return view('response',$response);

it will check for isset status, then if it returns true then set $message variable's value as "Success" , else "Failed".

then making this $message variable as an index of $response array and sending that to a blade file "response.blade.php".

Now create a blade file called 'response.blade.php', and add this code into it;

<html>
    <body>
        <div>{{ $message }}</div>
    </body>
</html>

is shows data present in the $message variable on our browser page,

Now, Fill that form again and hit save, I hope you can see this window;

Bingo, You just submitted the form through user interface and that data got saved to the database and you got its response back to the user interface :)

If you wish you can even pass 'name', 'age' indexes present in the $insertData array along with the message to show them too on your browser window. Like,

$response = [
      'message'=>$message,
      'name'=>$insertData['name'],
      'age'=>$insertData['age'],
];

I hope you understood this flow of sending data from user interface and saving it into the database;

Enjoyed learning it;

Lets learn about concept of Request & Response in my next article.

Bye :)

Laravel for Beginners : a Quick Guide - 6

Kartik Bhat — Sat, 14 Aug 2021 16:54:14 +0000

Blade Files !!!!

what are these blade files ?

Cool; simply these are just HTML files, styled using CSS and made interactive using JavaScript; yes that simple.

Then, Why these are called as blade files ?

Ok, before that I think you already know how to infuse PHP values/variables into our html file... I suppose...

using

<?php echo $value; ?>

Correct ?

then, how to add php's logical statements in html; you suppose to know this too :)

<div>
   <?php
       if(a>b) { 
   ?>
      <b><?php 
          echo "a is bigger" ; 
      ?></b>
      <?php 
       } else { 
      ?>
      <b><?php 
        echo "b is bigger" ; 
      ?></b>
  <?php 
     } 
   ?>
</div>

Correct ?

Don't you think these looks somewhat messy !!!
I think it is too messy :)

that's why laravel provides us a great solution, that is nothing but blade , to make user interface development more cleaner and easier.

Now, technically I can define this 'blade' as 'a template engine'; Laravel says it as 'Blade template engine', clear ?

Let's see how to write above piece of code using blade engine,

.blade.php file holds any html code in it, and no need to enclose anything within <?php ?> syntax, laravel handles it automatically.
any php variable can be printed using {{ }} syntax, add any php variable in between double flower brackets. it works similar to the echo .
logical statements such as 'if' and other statements can be infused by adding '@' before it, Eg:

'@if', '@elseif', '@endif', '@for', '@foreach', etc

any php logical statements can added similarly.

<?php ?> can be replaced by @php @endphp

Ok, Ok let's see about code;

<div>
   @if(a>b)
     <b>{{ 'a is bigger' }}</b>
   @elseif
     <b>{{ 'b is bigger' }}</b>
   @endif
</div>

Looks easy right ?

these blade files reside inside a view folder located under resources folder (Go and check them once)

from controller's method just we need to return name of the blade file, it is enough to load that respective blade file on browser when we call that controller's method using one of the route;

laravel provides a method called view() to load a blade file on the browser, and optionally we can pass php array (key - value pair) as a second parameter to the view function, that array can be accessed in our blade file.

Eg:
assume there is a file called viewData.blade.php present inside a resources->views folder; then we can load it from controller's method as

return view('viewData');

if we wish to pass a php array to it, then it looks like,

$data = [
   'name'=>'kartik'
];
return view('viewData',$data);

this is to simple one.. correct ?

Come On, Lets create a blade file and try its interaction with the controller;

create a file called viewData.blade.php inside a resources -> views folder

copy and paste this simple html code in it

<html>
    <body>
        <div>Hi, Hello</div>
    </body>
</html>

Now, lets create a controller's method to load it,
Open our DataController file the add this method to it;

public function loadPage() {
  return view('viewData');
}

Then, create a route to call this method,
I am sure you know that where to create it :)

Route::get('loadPage', [DataController::class,'loadPage']);

again to make things easy I am keeping route name and controller method's name as same, it is not mandatory to do it every time, you are free to use any words of your wish.

be remember route name should be unique, you cannot use same 'route' to call different methods of the controller :)

now call 'loadPage' route from your browser; you know this one too right ?

Ok, hit this url

http://127.0.0.1:8000/loadPage

you can see this;

seems to be a simple process right ? you just rendered a simple html file from Controller... is it ?; its a static data loading ; i.e you are not controlling the data to be displayed on browser window, its loading a string defined in a blade file itself.

Let's pass a php value from our loadPage() function and display it on browser window; say a dynamic data loading ;
you can control/customize the data to be displayed on browser window, below code says how to do it,

edit your loadPage() function as ;

public function loadPage() {
    $data = [
        'name' => "kartik"
    ];
    return view('loadPage',$data);
}

Open loadPage.blade.php file and remove that 'Hi , Hello' and add

{{ $name }}

index/key of an array $data that we have passed from loadPage() method. 'name' index of array $data can be referred as $name variable in our blade file.

<html>
    <body>
        <div>{{ $name }}</div>
    </body>
</html>

now, hit the same URL again;

what you are seeing ? index value that you have mentioned in loadPage() method... Correct ?

Interaction between controller and blade file is not so difficult right ? I Suppose :)

I hope you grasped it, in my next article let's learn about saving data to database that we will add from blade file and show them in a different page, OK

Bye :)

Laravel for Beginners : a Quick Guide - 5

Kartik Bhat — Fri, 13 Aug 2021 03:58:01 +0000

Yeah, I hope you understood my previous post on creating & configuring a database in to our Laravel Application and accessing through Controller via Model; Ok

(I believe you have some knowledge on MySQL - at least what it is; else do learn it before proceeding further)

Now, let's see about accessing database table to

insert a data
read a data

in my previous article you might noticed this instruction,

$dataValues = Data::get();

this will fetch all data present in the table 'data' from our database.

Let's create two routes now, (you know where to do it I suppose)

One for inserting data
One for reading it

Usually, in any kind of application request raises from User Interface(a front-end) part and that request processed in the another part (a back-end)

here in our laravel application, request raises from .blade.php files(usually) then those processed in the Controller ; a basic pinch.

Eg: to insert a data, it usually comes from user interface to save it (a form submit :)), and also to read data , request should come from user interface itself (a page load, a button click :) ) Got ?!!

to make the concept easy here I am creating some dummy data in our controller itself and then I read it.
(don't worry, again I will revisit a concept of getting data from user interface , saving it to the database and sending response back to user interface ;)

Now, Lets create two routes,

Route::get('saveData', [DataController::class,'saveData']);

Route::get('readData', [DataController::class,'readData']);

I think you can define these, you are fit enough I suppose ;)

'saveData' route calls saveData() function written under DataController Class
'readData' route calls readData() function written under DataController Class

Correct ?

So, Lets write those function under DataController,

public function saveData() {
      $insertData = [
          'name' => 'Kartik',
          'age' => 27
      ];

      $insertedData = Data::create($insertData);
 }

here I am creating an array $insertData, adding two indexes/keys 'name' and 'age', then adding values for those those indexes/keys, You observed it right :)

then I am calling Data model's object to insert data into the database, for that I am using create() method, its a laravel feature.

Notice that I am taking indexes/keys of $insertData array same as 'data' tables attributes and those should be present inside a $fillables array declared within 'Data' Model Class as well, (Open 'Data' model class and verify it once)

Doubt ? Where I am taking 'id' , 'created_at' , 'updated_at' !!!
Do I really need to add it ?
I say no, because while creating migration of the 'data' table, I have mentioned 'id' as an auto incrementing attribute so it will get a new value automatically when new data arises at the table then it gets incremented, then for 'created_at' and 'updated_at' attributes, laravel migration made them timestamp values and they receive current timestamp as there default values.

It's clear right ?

Ok, Now to insert data; open you browser hit an url with a route saveData (I hope you are already running WAMP/XAMPP server and done with php artisan serve command)

http://127.0.0.1:8000/saveData

Hurray, data got inserted to the database;

Try to hit same url again, it again inserts another data with same 'name' and 'age' but different 'id'... observe that 'id' got incremented.

you are seeing a blank white window !!!?

Ok, let's show some status of insert operation then,

in our saveData() method, after 'create' statement add ;

dd($insertedData);

like,

** What is this dd() !!! **

simply; dump and die :)

this method stops execution there itself and displays parameter passed to it on our browser window... simple right ?

Lets try it,
Hit same url again;
I am assigning status of create() method to a variable called $insetedData and passing it as a parameter to the dd() method, so it show contents of $insetedData on our browser window.

You can see this on your browser screen,

open "attributes" among those data, you can observe data inserted by you along with other attributes.

Bit Easy !!! correct or not ?

Similarly, read data too an easy concept, let's see about it;

there are some data present in the table 'data', that you have added using 'route' call, now we can list out them all;

to do that; you already came across this statement !!!

Yes, that is nothing but,

$fetchedData = Data::get();

to view this fetched data, just do again that dd(); :)

pass $fetched data array to dd();

Now, hit 'readData' route from your browser,

http://127.0.0.1:8000/readData

you can see this result on your browser window,

you are seeing 3 records present in our 'data' table, correct ?
this is too a simple one right ?

Ok, Hope you understood saving and reading data from database and getting its status on our browser..

Let's enter into the User Interface part in my next article,

Bye :)

Laravel for Beginners : a Quick Guide - 4

Kartik Bhat — Thu, 12 Aug 2021 04:42:17 +0000

Ok, Hope you understood my previous post on creating a new route and new controller

Now, today I will try to explain how the controller interacts with the model

Model !!

Cool, Model is nothing but an another .php file , say a PHP class; where interaction with a database's table happens actually;

now to interact with database table first we need to create a database and need to configure it with our Laravel application...

I hope you are already running your WAMP/XAMPP server (each time while reading my post don't forgot do this in the beginning, if you server is not running)

Ok, now open MySQL admin present in your server,
in case of WAMP ; hit this URL in your browser

http://localhost/phpmyadmin

you can see this window then,

by default username will be root and password is nothing (just leave it blank) hit enter (click on GO),

then you will be redirected to this page;

now, you need to create new database, to do that click on New,

It will prompt you to the page where you need to mention the database name;

enter database name as my-app (our application name :) )

then click on create, it will create a new database; cool :)

Hurray, you just created a new database :)

Ok, Lets configure it with our Laravel app;
Open .env file present inside our Laravel application directory.

initially it looks like this;

then change value of DB_DATABASE to ###my-app### and save :)

You were done with database configuration; Yes it is really simple :)

now, you need to create a table to save some data into the created database, for that you need to create database migration file;

to do that run this command in your command prompt within our Laravel application

php artisan make:migration create_data_table

you can observe a success message too,

this will create new .php file under database -> migrations folder(go and check existence of this file - current time stamp got automatically prepended to the file name)

Again , don't worry about those pre-existing migration files present there, those were created by laravel by default while installing our application

created migration file looks like this,

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateDataTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('data', function (Blueprint $table) {
            $table->id();
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('data');
    }
}

there are two methods up() and down(), on executing up() new table called 'data' will be created and on executing down() 'data' table will be dropped/deleted from the database if it is already exists, for now; do concentrate only on up(),

change content of up() to ,

 Schema::create('data', function (Blueprint $table) {
        $table->increments('id');
        $table->string('name',50);
        $table->integer('age');
        $table->timestamps();
 });

This is required create a table called 'data' with attributes

auto incrementing integer primary key 'id'
varchar 'name' with max length of 50
integer 'age'
timestamps; 'created_at' and 'updated_at'

now it time to migrate this schema at our server, to do that run this command (refer correct file name for the data table, here file name is specific to my computer)

php artisan migrate --path=/database/migrations/2021_08_11_165419_create_data_table.php

you can observe its status,

Bingo, this will create a new table called 'data' at our MySQL admin panel with those attributes mentioned above;

Open MySQL admin panel, and within our 'my-app' database we can observe 'data' table got migrated/created.

Ok, You are done with database's table creation, Now it is time to create a platform to access data present in the 'data' table, for that we need to create Model File, say a PHP file/class again :)

run this command to create a new Model File at app -> Models folder

php artisan make:model Data

you can observe its status,

now check this file at app->Models folder, it looks like this;

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Data extends Model
{
    use HasFactory;
}

then, you need to mentions attributes of 'data' table here, after adding required attributes this file looks like,

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Data extends Model
{
    use HasFactory;

    protected $fillable = [
        'id',
        'name',
        'age',
        'created_at',
        'updated_at'
    ];
}

Ok, Everything related to database creation and its configuration with our Laravel application got completed,

Now we need to call/utilize/refer this Model file/class in our Data Controller file/Class so that we can interact with the database,

to do so first we need to define/use Class name of Model at our controller,

add this anywhere after 'namespace' declaration (this is usually a first line of our PHP class, so you should add anything after this line itself)

use App\Models\Data;

Now, By using Object of Class Data (our Model Class) we can access our database table 'data' anywhere within our Controller methods.

Eg :

$dataValues = Data::get()

this will fetch all data present under 'data' table of our database 'my-app'

usage of :: is a syntax from Laravel,

Ok, This is all about accessing Database through Model in our Controller, Lets meet in the next concept on displaying a data fetched from database on our UserInterface / Browser / our blade.php file.

Bye :)

Laravel for Beginners : a Quick Guide - 3

Kartik Bhat — Wed, 11 Aug 2021 02:44:32 +0000

I hope you tried to understand my previous post on laravel application structure and how it works in general, Today here I am providing you the code level explanation of it...

You observed the word request raised multiple times while reading about work flow of Laravel application, it goes to routes then to controller then to model and then here and then there.... ok... ok...

I think now you got a doubt regarding how that request actually transits through these hurdles in this cycle ?

Wait, I am coming there itself :)

Request initiates from user interface

User Interface !!!
it is nothing but executed/processed state of your HTML file, now you got it at least :), here in our terminology we call it as "VIEWS"; there is a sub folder present under resources folder (go to file structure and find it). all your so called HTML codes files exists here.

I have one point to add : Laravel, a PHP's framework here even though you are writing HTML code under views folder but still those files should contain .php as their extension. Mind it...

all the files/user interface files created under views folder has an extension .blade.php

What ? .blade !!! What is this again ?

Cool; Let know know about it soon

hitting an URL, Clicking a button may a initiate a request to the application. here a route , say a key word is used to raise a request

Now again come to the main point, hit the URL provided by the command prompt.

I think you got this window,

Right ? now observe your URL bar : 127.0.0.1:8000 (in my case)

here at the end of this address along with a '/' symbol we can call any route. (here there is no specific keyword mentioned so it goes to '/' route)

did't got ? :(

Ok, if you want to call/use any route, first you need to register/define it in the application.

Then How to do it ?

Open routes folder under application folder the open web.php
it looks like,

here you can observe '/' route got defined !!!

do not worry about get() method, I will tell about its importance later

here '/' route is returning a view called welcome

returning a view means it calls a .blade.php file located under resource's subfolder views

route can either return a view or it can call a specific method/function defined under specific Controller i.e control/request then shifts to the Controller's method

Route::get('/', function () {
    return view('welcome');
});

here you can see route '/' is returning a view welcome (no need to append .blade.php extension to it, Laravel manages it automatically)

now let see, how request got transited to controller;
As I already said that route will again call specific method of specific controller,

What is Controller then ?
in general, Controller is authentic PHP class, a .php file located under App -> Http -> Controllers folder (go and check existence of this folder in your application)

Why we need to controller then ?
request received from user interface got processed in the Controller, processed in the sense it either generates data or fetches data from the database with an intervention of Model

How to create controller ?
open command prompt in our Laravel application folder, then enter this command

php artisan make:controller DataController

you can observe a success message

this will create a file called DataController under App-> Http-> Controllers Folder

now you need to pass controller from route to this controller's method, Ok before that write a function under DataController File (say a PHP class) , which returns a view welcome

after adding a method/function our DataController looks like this

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class DataController extends Controller
{
    public function welcomeFunction() {
        return view('welcome');
    }
}

Write a new route under web.php like

Route::get('welcome', 'DataController::welcomeFunction');

now our web.php file looks like this

<?php

use Illuminate\Support\Facades\Route;
use App\Http\Controllers\DataController;

/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/

Route::get('/', function () {
    return view('welcome');
});

Route::get('welcome', [DataController::class,'welcomeFunction']);

observe DataController file got defined before its usage (look at the top section of web.php , DataController file called with key word use , every controller should be call/define here first then we can use them futher... keep it in mind...)

Ok, Now are ready to hit new route created just now...

open your browser (I hope you already running our Laravel application :) ) then hit

** http://127.0.0.1:8000/welcome **

Bingo,

Your new route is perfectly working...

Your are seeing same window/page with both '/' and with '/welcome' routes... check them again... :)

Fine, Hope you got creation of new route and new controller and its function from this article, I will be back with Model interaction with Controller

Thank You

Bye :)

Laravel for Beginners : a Quick Guide - 2

Kartik Bhat — Tue, 10 Aug 2021 02:21:16 +0000

Laravel File Structure

Hope you understood my previous post on Laravel's introduction and its installation

Now Let's see, how the installed Laravel folder looks alike and what each subfolder says...

in this articles it is sufficient, if you understand only a importance of the each subfolder you see, again in the upcoming article I will revisit each folder wherever it is necessary... Don't worry about it.. :)

Ok let's start,

app

it is a core part of our Laravel application, major part of the development happens here, so keep in mind this folder play a key role every time.
it has 5 subfolder by default (we can create our subfolder too as a need of customization)

Console
Exceptions
HTTP - very important !!! (it holds all business logic - a controller files under Controllers sub folder)
Models - very important too !! (it holds all database connecting related files)
Providers - somehow important too :)

bootstrap

it is a folder where application's cache data resides, for now no need to worry about it much, OK
it has one subfolder

cache

config

config is one among important folders under Laravel application folder, where all the configurations related to application were defined, Keep it in mind...

database

database folder has a role with respect to database operations of the application, it holds data creation factory files, database table migrations and data seeding logic...
Again Don't worry I will revisit this folder in depth... :)

it has three subfolders in it

factories
migrations
seeders

public

ohho.... its a public place :)
cool : , I means all publicly accessible files were kept here so that application can access these at any time while execution. I hope its enough as of now... I will speak about it again.. :)

it contains folder like js, css, images etc

resources

its a place where all the expected resources of the application lies, as of now you just remember this folder holds all User Interface related files (your html files - under views subfolder)

routes

this folder holds those files, which defines a route; say a key word by how interaction with an application can be achieved, in generally route is an entry point to the application or to its functionality. As of now just concentrate on web.php file under this folder.

storage

this folder holds those files generated by framework, a place where we can get logs related to application's run time behaviour and application uses it to cache some data too...

tests

As laravel provides automated tests; this folder is meant to save those all; ok it is not so important as of now.

vendors

this folder too an important folder among others, it holds all the data of installed/added/adopted third party libraries/plugins, specifically a laravel plugins...

Ok, apart from these; under Laravel folder there is another factor to mention that is .env file

.env file

it an important file where primary configurations of the application resides, it says about many factors that our Laravel application can easily access.

then we have

composer.json

this is too an important file, which says about installed third party libraries and their versions, connects our application to the composer

How Laravel Application Works

now, after visiting file structure of our application, you may rise a point how actually it works or it runs/executes ?
let's see that concept...

after running the application through command prompt you will get an url, Ok hit that url in your browser...

Wait, Let me explain this diagrammatically,

.
.
.
.
.
.

What You got ? Any hint..... :)
Ok, in simple words, Browser connected to route, route connected to controller , controller connected to model and browser, then finally model connected to the database... right ? I hope you grasped these at least,

Ok technically I can redefine it as - Browser requests through the route, route then requests to controller, controller interacts with the model and model interacts with the database.

More Specifically, request raises from user interface(browser page)
by calling the route, then route shifts the control to the controller, then controller deals with request either processes data or interacts with model to read/write/update/delete operations, then model actually executes controller's expected operations with database then responds back the status to the controller, then controller responds back to the user interface, this as a whole we can call it as MVC interaction.

Ok, Lets see about conceptualizing of M-V-C on code level in my next article.

Hope you understood little about these...

Thank You
Bye :)

Laravel for Beginners : a Quick Guide - 1

Kartik Bhat — Sun, 08 Aug 2021 16:03:03 +0000

Laravel
PHP’s MVC framework, say a popular one too

It is developed by Taylor Otwell, thank him for making our web development somewhat easier, its current version is 8.x

What you need before dive into it?

Cool :)

basics of HTML, CSS, JS and PHP is enough (I hope you know these at least or learn them first)

I am sure developing web application using Laravel is easy (hope so) and interesting too :)

Laravel is a PHP Framework

What is Framework?

Simply, a set of pre-developed files that makes our development easier and faster, we develop->code our ideas on top of these files...

Why we need Framework?

Reduces development time, avoid developing simple components too, then finally we can get relief from scratching our head for managing data flow between multiple files ( but of course frequently we need to scratch our head for logical reasons :| )

If you feel you are creative - you have patience - eager to explore then for a sure Laravel thrills you...

Lets Begin,

Laravel follows a MVC architecture ...

What is MVC?

MVC is an architecture where Database Operations - Business Logic - View (visual representation) were kept separately.
It makes code readability easier
also makes our work easier too :)

MVC - Model - View - Controller

Model - Place to write all database related code
View - Where we write UI related code
Controller - Holds an actual logical part, acts as a mediator between Model and View

System Requirements

Apache Server - install either WAMP (easier) /XAMPP
Composer
Browser
IDE - I prefer VSCode

.
.
.
.
.
.
.
.
.
.
.
.
.

I hope you were done with installation :)

then to run server

If you are using WAMP

just double click on

you can observe the transition status of WAMP server
Starting/Error -
Partially Completed -
Started Successfully -

If you are using XAMPP

just double click on

then within its interface start Apache and MySQL

then open browser hit http://localhost

if a page related
to WAMP/XAMPP loads properly then it is clear that server started properly else there might be some problems with your system

open cmd - a command prompt and enter composer

if it shows like this

it justifies that composer got installed successfully

Got Tired after these steps :(
Don't worry you are just one step away from Laravel installation...

come lets do that one too :)

Open command prompt at you desired location in your system
Now you are installing LARAVEL through using composer
enter a command

composer create-project laravel/laravel my-app

wait for a while to install all necessary dependencies

then, Bingo

LARAVEL got installed, then you can see these messages

Then How to run this Application ?

That too still simple,

open command prompt inside a created laravel project

then enter
php artisan serve
You will get an URL, where our Laravel app is running

Ok... the last step :)
last one...

open the browser then hit the URL provided in a cmd propmt...

Hurray !!!!!

Our Laravel Application is running

Enough for now right!!!... Ok

I hope you gained some hint on What is Laravel? and How to install it?

Lets meet in the next topic on Laravel Application Structure and how MVC induced in it...

Bye :)

DEV Community: Kartik Bhat

Laravel for Beginners : a Quick Guide - 8

Laravel Routes

Mistyped routes/requests

Routes and Form submit

http://127.0.0.1:8000/addData

Laravel for Beginners : a Quick Guide - 7

Laravel for Beginners : a Quick Guide - 6

be remember route name should be unique, you cannot use same 'route' to call different methods of the controller :)

http://127.0.0.1:8000/loadPage

Laravel for Beginners : a Quick Guide - 5

http://127.0.0.1:8000/saveData

http://127.0.0.1:8000/readData

Laravel for Beginners : a Quick Guide - 4

Model !!

http://localhost/phpmyadmin

Laravel for Beginners : a Quick Guide - 3

What ? .blade !!! What is this again ?

Laravel for Beginners : a Quick Guide - 2

Laravel File Structure

app

bootstrap

config

database

public

resources

routes

storage

tests

vendors

How Laravel Application Works

Laravel for Beginners : a Quick Guide - 1

What you need before dive into it?

Laravel is a PHP Framework

What is Framework?

Why we need Framework?

If you are using WAMP

If you are using XAMPP

then open browser hit http://localhost

open cmd - a command prompt and enter composer