Rammina

Posted on Nov 24, 2021 • Updated on Dec 27, 2021 • Originally published at rammina.com

Day 47 of 100 Days of Code & Scrum: I Finally Fixed the CORS Bug!

#100daysofcode #beginners #javascript #programming

Hello there, everyone!

I was finally able to solve the bug I was stuck on for 2 days.

Access to XMLHttpRequest at API_GATEWAY_ENDPOINT from origin http://localhost:3000 has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource

What I did was limit the allowed methods for my API Gateway HTTP API to just POST and OPTIONS methods. I also made sure that the preflight OPTIONS request did not interact with my Lambda function, and only the POST request containing the form data does. Finally, I manually set the access-control headers instead of letting AWS handle it for me automatically, and I was able to fix the issue.

Anyway, let's move on to my daily report!

Yesterday

I was stuck on this bug:

I learned a lot from reading multiple whitepapers about AWS API Gateway, Lambda, and SES.

Today

Here are the things I learned and worked on today:

Company Website

I managed to solve the bug above.
added validation for my contact form.
display success message if the message goes through and an error notification if it fails.
changed the color scheme for my navigation bar.
added a close button for my navmenu.

Scrum

learn the key differences between Scrum and Kanban.
read a blog post about Scrum and how it uses be principles of Empiricism.
I did some practice flashcards for Scrum.
reviewed some of the things I've learned before.

Thank you for reading!

Resources/Recommended Readings

DISCLAIMER

This is not a guide, it is just me sharing my experiences and learnings. This post only expresses my thoughts and opinions (based on my limited knowledge) and is in no way a substitute for actual references. If I ever make a mistake or if you disagree, I would appreciate corrections in the comments!

Other Media

Feel free to reach out to me in other media!

Top comments (0)

11 Tips That Make You a Better Typescript Programmer

1 Think in {Set}

Type is an everyday concept to programmers, but it’s surprisingly difficult to define it succinctly. I find it helpful to use Set as a conceptual model instead.

#2 Understand declared type and narrowed type

One extremely powerful typescript feature is automatic type narrowing based on control flow. This means a variable has two types associated with it at any specific point of code location: a declaration type and a narrowed type.

#3 Use discriminated union instead of optional fields

...

Read the whole post now!

DEV Community