Displaying validation errors in Laravel - Step-by-Step Execution

Concept Flow - Displaying validation errors

User submits form

↓

Controller validates input

↓

Validation passes?

No→Redirect back with errors

↓

Errors stored in session

↓

Process data

↓

Show success

This flow shows how Laravel checks form input, stores errors if any, and then displays them back in the form.

Execution Sample

Laravel

<?php
$request->validate([
  'email' => 'required|email',
  'password' => 'required|min:6'
]);

This code validates that email and password fields meet rules; if not, Laravel redirects back with errors.

Execution Table

Step	Action	Input Values	Validation Result	Next Step
1	User submits form	{email: '', password: '123456'}	Validation fails (email required)	Redirect back with errors
2	Errors stored in session	N/A	Errors saved	View reads errors
3	View displays errors	N/A	Shows 'The email field is required.'	User sees error message
4	User submits form	{email: '[e-mail]', password: '123'}	Validation fails (password min 6)	Redirect back with errors
5	Errors stored in session	N/A	Errors saved	View reads errors
6	View displays errors	N/A	Shows 'The password must be at least 6 characters.'	User sees error message
7	User submits form	{email: '[e-mail]', password: '123456'}	Validation passes	Process data and show success

💡 Validation passes only when all rules are met; otherwise, errors redirect back to form.

Variable Tracker

Variable	Start	After Step 1	After Step 4	After Step 7
email	''	''	'[e-mail]'	'[e-mail]'
password	''	'123456'	'123'	'123456'
errors	empty	['email' => 'required'] error	['password' => 'min:6'] error	empty

Key Moments - 2 Insights

Why does Laravel redirect back instead of showing errors immediately?

Laravel redirects back to keep the form input and errors in session so the view can display them; see execution_table steps 1 and 2.

How does the view know which errors to show next to each field?

Laravel stores errors keyed by field name in session; the view accesses these keys to display messages next to the right inputs, as in execution_table step 3.

Visual Quiz - 3 Questions

Look at the execution table, what validation error appears at step 1?

A The email field is required

B The password must be at least 6 characters

C No errors, validation passed

D The email must be a valid email address

💡 Hint

Check the Validation Result column at step 1 in the execution_table

At which step does the validation finally pass?

A Step 3

B Step 5

C Step 7

D Step 2

💡 Hint

Look for 'Validation passes' in the Validation Result column

If the password was 'abcdef', how would the errors variable change after step 4?

A It would contain a password error

B It would be empty

C It would contain an email error

D It would contain both email and password errors

💡 Hint

Refer to variable_tracker for password and errors values after step 4

Concept Snapshot

Laravel validation checks input rules on form submit.
If validation fails, Laravel redirects back with errors stored in session.
The view reads these errors and shows messages next to inputs.
Validation passes only if all rules are met.
Use $errors variable in Blade to display messages.

Full Transcript

When a user submits a form in Laravel, the controller runs validation rules on the input. If any rule fails, Laravel does not process the data but instead redirects back to the form page. It stores the validation errors in the session so the form view can access them. The view then displays these error messages next to the relevant form fields, helping the user fix their input. This cycle repeats until all validation rules pass, at which point the controller processes the data normally. This flow ensures users get clear feedback on what needs fixing in their form submission.