TIPS | DEV NOTE

How to Fix the "EADDRINUSE" and "127.0.0.1:9292" Errors When Developing Shopify Themes

In this article, I’ll explain the causes of the “EADDRINUSE: address already in use 127.0.0.1:9292” error encountered when developing Shopify themes, how to check the port using `lsof` and terminate the process, and how to switch to a different port using the `--port` option.

2026.03.20

TIPS

Causes and Solutions When CSS Backward Compatibility Doesn't Work

We’ve compiled a guide on the causes and solutions for when CSS suffix matching doesn’t work, covering everything from compatibility with the `class` attribute to how to distinguish between word-based and suffix-based matching. We’ve also summarized the steps you should take first to troubleshoot the issue.

2026.03.20

TIPS

A Beginner's Guide to CSS Flexbox: A List of Properties and Practical Examples

This guide provides a comprehensive overview of CSS Flexbox, covering everything from the basics to the use of `flex-direction`, `justify-content`, `align-items`, and `flex-wrap`, as well as practical examples using colored boxes, navigation menus, card layouts, and forms, along with important considerations.

2026.03.20

TIPS

How to Create a Shortcut to Convert Text (Images) on Your Mac Screen to Text and Copy It

This guide provides a detailed explanation of how to create a custom efficiency tool that uses the Mac’s built-in “Shortcuts” app to instantly extract text (OCR) from images and videos on your screen and copy it. It’s significantly faster and more accurate than AI-powered OCR, and it even supports vertical text. No external apps are required—simply press a designated key to select the area, and the text is converted instantly. We’ll walk you through all the practical setup steps you’ll need for real-world use.

2026.03.19

TIPS

How to Use WP-CLI: Commands That Dramatically Streamline WordPress Management

From an overview of WP-CLI to installation instructions, bulk updates, and database "search-replace" operations, we’ll explain practical ways to use it to significantly streamline and speed up your WordPress operations and management.

2026.03.19

TIPS

Thorough explanation of CSS colspan and rowspan

Learn more about colspan and rowspan for joining cells in HTML tables.

2024.10.30

TIPS

Solution to the problem of CSS changes not being reflected in real time in BrowserSync.

Learn how to solve the problem of BrowserSync not reflecting CSS changes in real time in WordPress development.

2024.10.29

TIPS

How to make an FTP connection between a Mac and a Sony camera

This section explains how to connect your Mac and Sony camera via FTP for easy photo transfer.

2024.10.28

TIPS

How to remove dotted lines during Button focus and notes

This section explains how to remove the dotted line when Button is in focus and what to do about it.

2024.10.28

TIPS

How to get raw content instead of rendered with WordPress REST API

This section explains how to use the WordPress REST API to get raw content instead of rendered.

2024.10.28

TIPS

Problem with WordPress REST API not accessible from GAS on Xserver and how to resolve it

Describes how to solve the problem of not being able to access the WordPress REST API from GAS on Xserver.

2024.10.28

TIPS

How to solve toc.js not working in WordPress

This page explains how to solve the problem of toc.js not working in WordPress by using the order in which jQuery is loaded.

2024.10.28

TIPS

How to check character count in VS Code without extensions

Learn how to check the number of characters in VS Code without extensions.

2024.10.28

TIPS

Problems with WordPress Site Kit not outputting analytics tags and how to resolve

Here is a solution to a problem with WordPress Site Kit not outputting analytics tags.

2024.10.28

TIPS

Problem with image alt text not being reflected in WordPress posts and how to resolve it

How to solve the problem of images not reflecting alt text in WordPress and why it is important.

2024.10.28

TIPS

Useful image display technique combining aspect-ratio and object-fit

By combining the aspect-ratio and object-fit properties of CSS, you can maintain the aspect ratio of an image and fine-tune the way the image is displayed while supporting responsive design.

2024.09.20

TIPS

Usage about the third argument of get_template_part()

The third argument of get_template_part() is used to explain how to pass variables to the template and how to safely check them with the isset() function.

2024.09.20

TIPS

How to mix and match custom posts on post pages

If you want to mix and match custom posts on your WordPress post pages, here's how to customize your query using the pre_get_posts action hook.

2024.09.20

TIPS

Specifying files with Gulp’s glob pattern

This section describes how to specify files using Gulp's glob pattern.

2024.09.20

TIPS

Google Spreadsheet App Script error resolution: How to deal with “TypeError: Cannot read properties of undefined (reading ‘getSheetByName’)

This article explains how to resolve the "TypeError: Cannot read properties of undefined (reading 'getSheetByName')" error that occurs in the App Script for Google Spreadsheets. It details the technical background as well as effective ways to deal with the issue, including restarting the editor and explicitly retrieving the spreadsheet.

2024.09.20

TIPS

Solutions for when CSS doesn’t display the way you want it to

If an element does not display the way you want it to in CSS, it is important to check the display attribute settings. This section details examples of specific problems and their solutions.

2024.09.11

TIPS

How to check for broken theme errors and parent themes

Learn more about errors when a child theme does not recognize its parent theme in WordPress and how to resolve them.

2024.09.11

TIPS

What to do if engagement (PV) is not displayed in Google Analytics

This section explains the causes of why engagement is not showing up in Google Analytics and the solution to change the report to public.

2024.09.11

TIPS

What to do if text-overflow: ellipsis; does not work

This section details the causes of text-overflow: ellipsis; not working and how to deal with it, such as display: block;.

2024.09.11

TIPS

How to not align the height of small elements with display: flex (to match the content)

This section explains how to use align-items: start to align Flexbox child elements with the content without aligning their heights.

2024.09.02

TIPS

Recommended Development Environments for Web Coding: Thorough Explanation from Hardware to Software

An appropriate development environment is essential for efficient web development. This article introduces the best deve...

2024.09.01

TIPS

How to center with writing-mode: vertical-rl (Firefox support)

Explains how to center a page with vertical writing mode writing-mode: vertical-rl, including how Firefox supports it, using inline-block or Flexbox instead of margin: auto to achieve the intended layout.

2024.08.31

TIPS

How to output title attribute in wp_nav_menu

This course explains how to output the title attribute in WordPress wp_nav_menu through the creation and use of a custom walker class, a technique that can help improve SEO and user experience.

2024.08.31

TIPS

How to ignore files already managed by Git: how to use assume-unchanged and skip-worktree

Explanation of how to use assign-unchanged and skip-worktree to ignore files already managed in Git. Understanding the uses and differences and using them appropriately prevents accidental commits.

2024.08.31

TIPS

How to solve the problem of custom fields disappearing on save in WordPress

This page explains why custom fields disappear in WordPress and how to solve the problem. The cause is due to a low PHP setting max_input_vars, which can be solved by adjusting the setting.

2024.08.31

TIPS