Resource controllers in Laravel - Step-by-Step Execution

Concept Flow - Resource controllers

Route receives HTTP request

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Route linked to Resource Controller

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Controller method matched by HTTP verb and URL

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Controller method executes logic

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Return response (view, redirect, JSON)

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Client receives response

The flow shows how a Laravel route maps HTTP requests to resource controller methods based on the request type and URL, then returns a response.

Execution Sample

Laravel

Route::resource('photos', PhotoController::class);

// HTTP GET /photos -> index()
// HTTP GET /photos/1 -> show(1)
// HTTP POST /photos -> store()

This code registers a resource controller that automatically maps HTTP verbs and URLs to controller methods.

Execution Table

Step	HTTP Request	Matched Controller Method	Action Taken	Response
1	GET /photos	index()	Fetch all photos	Return photos list view
2	GET /photos/1	show(1)	Fetch photo with ID 1	Return photo detail view
3	POST /photos	store()	Validate and save new photo	Redirect to photos list
4	PUT /photos/1	update(1)	Validate and update photo ID 1	Redirect to photo detail
5	DELETE /photos/1	destroy(1)	Delete photo ID 1	Redirect to photos list
6	GET /photos/create	create()	Show form to create photo	Return create photo form view
7	GET /photos/1/edit	edit(1)	Show form to edit photo ID 1	Return edit photo form view
8	PATCH /photos/1	update(1)	Validate and update photo ID 1	Redirect to photo detail
9	GET /unknown	No match	No controller method	404 Not Found

💡 Execution stops when a matching route and controller method is found or 404 if no match.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	After Step 6	After Step 7	After Step 8	Final
HTTP Request	None	GET /photos	GET /photos/1	POST /photos	PUT /photos/1	DELETE /photos/1	GET /photos/create	GET /photos/1/edit	PATCH /photos/1	GET /unknown
Controller Method	None	index()	show(1)	store()	update(1)	destroy(1)	create()	edit(1)	update(1)	No match
Response	None	Photos list view	Photo detail view	Redirect to photos list	Redirect to photo detail	Redirect to photos list	Create form view	Edit form view	Redirect to photo detail	404 Not Found

Key Moments - 3 Insights

Why does a GET request to /photos call the index() method?

Because the resource controller maps GET /photos to the index() method as shown in execution_table row 1, which is the standard for listing resources.

What happens if the URL does not match any resource route?

As shown in execution_table row 9, no controller method matches, so Laravel returns a 404 Not Found response.

How does Laravel know which method to call for POST /photos?

The HTTP verb POST combined with the URL /photos matches the store() method in the resource controller, as seen in execution_table row 3.

Visual Quiz - 3 Questions

Look at the execution table, which controller method handles GET /photos/1/edit?

A update(1)

B show(1)

C edit(1)

D create()

💡 Hint

Check execution_table row 7 for GET /photos/1/edit

At which step does the response become 'Redirect to photos list'?

A Step 3

B Step 4

C Step 5

D Step 6

💡 Hint

Look at execution_table rows 3 and 5 for redirect responses

If you send a DELETE request to /photos/1, what response will you get?

A Photo detail view

B Redirect to photos list

C Create photo form

D 404 Not Found

💡 Hint

See execution_table row 5 for DELETE /photos/1

Concept Snapshot

Resource controllers in Laravel map HTTP verbs and URLs to controller methods automatically.
Use Route::resource('name', Controller::class) to register.
Common methods: index(), create(), store(), show(), edit(), update(), destroy().
Each method handles a specific action (list, show, create form, save, edit form, update, delete).
Laravel routes requests to these methods based on HTTP verb and URL pattern.
Unmatched routes return 404 Not Found.

Full Transcript

Resource controllers in Laravel help organize code by linking HTTP requests to controller methods automatically. When you register a resource controller with Route::resource, Laravel sets up routes for common actions like listing all items, showing one item, creating, updating, and deleting. For example, a GET request to /photos calls the index() method to list photos, while a POST to /photos calls store() to save a new photo. If a request URL does not match any resource route, Laravel returns a 404 error. This flow makes it easy to build RESTful applications by following a simple pattern.

Practice

1. What is the main purpose of a resource controller in Laravel?

easy

A. To create views without a controller

B. To handle database migrations automatically

C. To group all CRUD actions for a resource in one controller

D. To manage user authentication only

Solution

1. Step 1: Understand what resource controllers do

   Resource controllers in Laravel group related actions like create, read, update, and delete (CRUD) for a resource in one controller class.

2. Step 2: Compare options with this definition

   Only To group all CRUD actions for a resource in one controller correctly describes this grouping of CRUD actions. Other options describe unrelated features.

3. Final Answer:

   To group all CRUD actions for a resource in one controller -> Option C

4. Quick Check:

   Resource controller = CRUD grouping [OK]

Hint: Resource controllers group CRUD actions in one place [OK]

Common Mistakes:

• Confusing resource controllers with migrations
• Thinking resource controllers handle views alone
• Assuming resource controllers manage authentication

2. Which of the following is the correct syntax to register a resource controller named PostController for the route /posts?

easy

A. Route::resource('posts', PostController::class);

B. Route::controller('posts', PostController::class);

C. Route::get('posts', PostController::resource());

D. Route::resource('PostController', 'posts');

Solution

1. Step 1: Recall Laravel resource route syntax

   The correct syntax uses Route::resource('uri', ControllerClass::class) to register all resource routes.

2. Step 2: Check each option

   Route::resource('posts', PostController::class); matches the correct syntax. Route::controller('posts', PostController::class); uses controller which is different. Route::get('posts', PostController::resource()); is invalid syntax. Route::resource('PostController', 'posts'); swaps parameters incorrectly.

3. Final Answer:

   Route::resource('posts', PostController::class); -> Option A

4. Quick Check:

   Resource route syntax = Route::resource(uri, Controller::class) [OK]

Hint: Use Route::resource('uri', Controller::class) to register resource routes [OK]

Common Mistakes:

• Using Route::controller instead of Route::resource
• Swapping URI and controller parameters
• Calling resource() as a method on controller instance

3. Given this resource controller route registration:
Route::resource('photos', PhotoController::class);
Which URL and HTTP method will call the destroy method in PhotoController for photo with ID 5?

medium

A. PUT /photos/5/destroy

B. GET /photos/5/destroy

C. POST /photos/5/delete

D. DELETE /photos/5

Solution

1. Step 1: Recall resource route conventions for destroy

   The destroy method is called with HTTP DELETE on the resource URI with the ID, e.g., DELETE /photos/{id}.

2. Step 2: Match options to this pattern

   DELETE /photos/5 matches DELETE /photos/5. Other options use wrong HTTP methods or incorrect URLs.

3. Final Answer:

   DELETE /photos/5 -> Option D

4. Quick Check:

   Destroy = DELETE /resource/{id} [OK]

Hint: Destroy uses DELETE method on /resource/{id} URL [OK]

Common Mistakes:

• Using GET or POST instead of DELETE for destroy
• Adding extra path segments like /destroy or /delete
• Confusing PUT with DELETE method

4. Consider this route registration:
Route::resource('users', UserController::class);
Which of the following code snippets will cause a runtime error when trying to access the show method?

medium

A. public function show() { return 'User not found'; }

B. public function show(User $user) { return $user; }

C. public function show($id) { return view('user.show', compact('id')); }

D. public function show($id) { return User::findOrFail($id); }

Solution

1. Step 1: Understand show method parameter requirements

   The show method expects either an ID parameter or a model instance via route model binding.

2. Step 2: Analyze each option

   public function show() { return 'User not found'; } has no parameter, so Laravel cannot pass the required ID or model, causing a runtime error. Others have correct parameters.

3. Final Answer:

   public function show() { return 'User not found'; } -> Option A

4. Quick Check:

   Show method must accept ID or model parameter [OK]

Hint: Show method needs parameter for ID or model [OK]

Common Mistakes:

• Omitting parameters in show method
• Using wrong parameter types without binding
• Ignoring route model binding requirements

5. You want to create a resource controller for Product but only want to generate routes for index, show, and store methods. Which is the correct way to register this in routes/web.php?

hard

A. Route::resource('products', ProductController::class)->except(['create', 'edit']);

B. Route::resource('products', ProductController::class)->only(['index', 'show', 'store']);

C. Route::resource('products', ProductController::class)->skip(['create', 'edit']);

D. Route::resource('products', ProductController::class)->filter(['index', 'show', 'store']);

Solution

1. Step 1: Recall how to limit resource routes

   Laravel allows limiting routes using the only method with an array of method names.

2. Step 2: Evaluate each option

   A uses except(['create', 'edit']) which excludes only create and edit, leaving index, store, show, update, and destroy. B correctly uses only(['index', 'show', 'store']). C and D use invalid methods skip and filter.

3. Final Answer:

   Route::resource('products', ProductController::class)->only(['index', 'show', 'store']); -> Option B

4. Quick Check:

   Limit resource routes with only([...]) [OK]

Hint: Use ->only([...]) to limit resource controller routes [OK]

Common Mistakes:

• Using invalid methods like skip or filter
• Confusing only with except
• Not passing array to only method