Validation: Implement validation checks to ensure that the provided information is correct and complete.

[rlanier-webdev]

1. Registration and Sign-Up Validation:

• - Validate that all required fields (e.g., username, email, password) are provided.
• - Check for valid email format.
• - Verify that the username is unique and meets length requirements.

2. Password Validation:

• - Enforce password complexity requirements (length, uppercase/lowercase, numbers, special characters).
• - Ensure that the password and password confirmation match.

3. Email Verification:

• - Validate email addresses by sending a verification link.
• - Set an expiration time for the verification link.

4. Profile Completion Validation:

• - Ensure that mandatory fields (e.g., first name, last name) are completed during profile setup.

5. Date of Birth Validation:

• - Validate that the provided date of birth is realistic (e.g., not in the future) and within an acceptable range.

6. Numeric Input Validation:

• - Validate that numeric fields (e.g., age, phone number) contain only numeric characters.

7. Text Input Validation:

• - Prevent or sanitize input for potential HTML/script injection (cross-site scripting or XSS attacks).
• - Validate that text fields do not contain excessive or invalid characters.

8. File Upload Validation:

• - Validate file formats and sizes during file uploads (e.g., profile pictures).
• - Set limits on acceptable file types (e.g., image, PDF).

9. Dropdown and Selection Validation:

• - Validate that required options are selected from dropdown menus or radio buttons.

10. Address Validation:

• - Validate address fields for completeness and accuracy.

11. URL Validation:

• - Validate URLs to ensure they are well-formed and secure.

12. Phone Number Validation:

• - Validate phone number formats based on the applicable country's conventions.

13. Consent and Agreement Validation:

• - Ensure that users consent to terms of service, privacy policies, or any legal agreements.

14. Checkbox Validation:

• - Validate that required checkboxes are checked (e.g., agreeing to terms).

15. Character Limit Validation:

• - Enforce character limits for text fields (e.g., short descriptions, comments).

16. Uniqueness Validation:

• - Check for uniqueness of data such as usernames, email addresses, or other identifiers.

17. Numeric Range Validation:

• - Validate that numeric inputs (e.g., age) fall within an acceptable range.

18. Conditional Validation:

• - Implement conditional validation based on user choices or inputs.

19. Cross-Field Validation:

• - Validate relationships between fields (e.g., start date should be before end date).

20. Error Handling and Feedback:

• - Provide meaningful error messages explaining validation failures.
• - Highlight the fields that need correction.