Chee Wee's discoveries and tech blog

Delphi Observers Part 5: Validation in Action: TCheckBox

chuacw — Wed, 01 Apr 2026 05:45:00 GMT

In Part 4 , we saw how TEdit and TMemo 's ancestor: TCustomEdit uses observers to manage passive states like ReadOnly . However, TCustomCheckBox and...(read more)

Delphi Observers Part 4: Active Interception - TCustomEdit

chuacw — Mon, 23 Mar 2026 09:11:00 GMT

In the previous articles, we established how the observer engine is initialized. Now, let’s look at how a professional-grade component like TEdit...(read more)

Delphi Observers Part 3: The Component Gatekeeper

chuacw — Mon, 23 Mar 2026 08:54:00 GMT

In the previous article, we saw how TComponent initializes the observer engine. However, simply having an engine doesn't mean a component knows how...(read more)

Delphi Observers Part 2: Lifecycle: From Lazy-Init to Destroy

chuacw — Mon, 02 Feb 2026 06:34:00 GMT

In Part 1 , we looked at the interfaces that define the Observer pattern in Delphi. But how do these observers actually get created and managed within...(read more)

Delphi Observers Part 1: The Foundation (2017–2026)

chuacw — Mon, 05 Jan 2026 05:18:00 GMT

In 2017, with the release of Delphi 10.2 Tokyo, Embarcadero introduced a specialized implementation of the Observer pattern into the System.Classes unit. While it has been in the wild for 9 years, it remains a "hidden" architecture for many, primarily because it serves as the invisible engine behind LiveBindings. Other than live bindings, you can also use the Observer pattern as a way to update component settings to the Windows registry, an .ini file, or persist it elsewhere.

...(read more)

Why the RAD Studio IDE doesn't implement the "Follow" feature

chuacw — Thu, 11 Dec 2025 11:13:00 GMT

In the RAD Studio IDE, when you switch to assembly, and your [R]IP is on a call or a branch instruction, the IDE provides a "Follow" feature...(read more)

Converting TDateTime to TValue

chuacw — Sun, 30 Nov 2025 06:58:00 GMT

Previously, I talked about how the TDateTime triumvirate caused issues in runtime packages. Today, I'll discuss why using implicit operators with TValue...(read more)

Delphi: an inconsistent and illogical language

chuacw — Fri, 24 Oct 2025 13:05:00 GMT

The more Delphi is being used, the more you'll find that it is an inconsistent and illogical language. Over the years, Delphi has started becoming...(read more)

Solana lessons & resources

chuacw — Mon, 08 Sep 2025 14:51:48 GMT

A clearance list of Solana lessons & resources I've picked up recently. Intro to Solana and Blockchain Lesson video - https://youtu.be/vrO6cjdPUOs...(read more)

The history of TDateTime, TDate & TTime and why they cause issues in packages and libraries

chuacw — Fri, 01 Aug 2025 00:30:00 GMT

Last time, I talked about the $OBJTYPENAME directive . This post has a little something to do with it. There are issues with using TDateTime, TDate and...(read more)

Undocumented parameters for $OBJTYPENAME

chuacw — Thu, 17 Jul 2025 08:20:00 GMT

Currently, the documentation for $OBJTYPENAME is located at Embarcadero's docwiki: OBJTYPENAME directive (Delphi) . But if you look at System.pas in...(read more)

Embarcadero announces RAD Studio 13 beta

chuacw — Fri, 27 Jun 2025 18:04:56 GMT

Embarcadero has announced the RAD Studio 13 beta and invites customers to join it! Codenamed Ganymede, RAD Studio 13 will be named Florence. Only customers...(read more)

UInt64 bugs in the Delphi RTL

chuacw — Tue, 13 May 2025 05:54:25 GMT

I've been working on the JSON RPC framework, which was previously public , but has gone private . During its development, I've discovered at least...(read more)

How I fixed this blog to stop spam

chuacw — Fri, 25 Apr 2025 06:45:00 GMT

Over 4 months ago, I've enabled comments for blogs site-wide, and I wasn't aware at that time, but spam started coming in. Yesterday, I started...(read more)

Reverse engineering bundled Javascript code

chuacw — Mon, 24 Mar 2025 11:02:53 GMT

One of the ways to reverse engineer Javascript code that's bundled is to use an applet known as Shuji . Shuji is an applet that, in its owner's...(read more)

The undocumented Delphi signature directive

chuacw — Mon, 24 Mar 2025 10:51:24 GMT

I've accidentally stumbled upon the --no-compiler-signature directive that you can use to make your generated Delphi executable slightly smaller. Add...(read more)

How to resolve a stucked "file:" dependency in npm

chuacw — Wed, 02 Oct 2024 13:09:40 GMT

In npm, after running the npm link command to enable your package to be linkable, it's possible to get stuck in a dependency hell, where in the dependency...(read more)

Repairing snap on Ubuntu 24.04 LTS

chuacw — Mon, 03 Jun 2024 14:08:00 GMT

sudo apt install snapd sudo snap install snap-store sudo snap refresh --beta core22 sudo snap refresh --stable core22 sudo snap remove core24 sudo snap...(read more)

The anatomy of a Firefox add-on

chuacw — Wed, 06 Dec 2023 16:31:21 GMT

This month, I've learnt how to build a Firefox add-on, and learnt that if one desires to do so, there's practically no difference between a Firefox...(read more)

Building the foundation to access blockchains in Delphi

chuacw — Fri, 17 Nov 2023 23:46:00 GMT

Since late June, I've been building a framework to access any JSON RPC technologies in Delphi. I'm pleased to announce that the JSON RPC framework...(read more)

Preparing for writing Move contracts

chuacw — Fri, 21 Apr 2023 17:14:00 GMT

Since early April, I've discovered 2 new blockchains, Sui and Aptos. Both Sui and Aptos uses the Move language ( Sui variant ), and both of which uses...(read more)

RAD Studio plugin: WelcomePage Favourites Editor

chuacw — Thu, 02 Mar 2023 15:22:00 GMT

The WelcomePage Favourites Editor is an integrated plugin that you can add to the WelcomePage. After installation of the WelcomePage Favourites Editor...(read more)

RAD Studio plugin: Android Log Viewer

chuacw — Tue, 28 Feb 2023 11:31:22 GMT

The Android Log Viewer is an integrated plugin that launches automatically when it has detected that you've launched a debugging session. After installation...(read more)

A Plugin Common RTL for Delphi and many plugins built on it...

chuacw — Mon, 27 Feb 2023 12:55:00 GMT

Over the past few years, I've been building a RTL for building plugins in RAD Studio, with many classes and functionality. With the latest RAD Studio...(read more)

Using MSBuild to compile disables debugging

chuacw — Thu, 23 Feb 2023 09:11:07 GMT

In RAD Studio, checking the "Use MSBuild externally to compile" causes debugging to go into assembly mode, instead of the source. In order to...(read more)

Undocumented procedural type compatibility

chuacw — Thu, 19 Jan 2023 08:34:00 GMT

Recently, I stumbled upon a new undocumented procedural type compatibility in Delphi. Since Delphi 10.3, "reference to procedure" is compatible...(read more)

Notes on how to handle Ctrl+Click in the RAD Studio IDE

chuacw — Wed, 21 Dec 2022 23:15:00 GMT

The OTA provides a way for an IOTACodeInsightManager100 to handle GotoDefinition. Before Denali, the IDE would use the Syntax Highlight information for...(read more)

How to make Windows Terminal the default terminal on Windows 10/2022

chuacw — Wed, 16 Nov 2022 17:11:00 GMT

Open up regedit, and go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths Create a new key named cmd.exe and set its default value...(read more)

Why use an Assertion Function in TypeScript

chuacw — Mon, 31 Oct 2022 09:51:00 GMT

Recently, I was working on a developing a server that responds to JSON RPC calls using TypeScript. Many of the methods in the RPC server follows this template...(read more)

Delphi RTL for TypeScript

chuacw — Wed, 13 Jul 2022 10:48:00 GMT

Since early 2019, when I've started working on TypeScript, I've missed some routines from the Delphi RTL. While TypeScript, which transpiles to...(read more)

How to force a configuration variable to be false/true

chuacw — Tue, 12 Apr 2022 02:24:40 GMT

require("dotenv").config(); const FORCEUPDATE = String(process.env.UPDATESILENCE_FORCEUPDATE) == "true" The dotenv module makes the...(read more)

Tip of the day for Grafana

chuacw — Mon, 07 Mar 2022 16:03:14 GMT

💡Regular expressions in Grafana for silencing alerts have to match the entire value of the field for it to work. A partial match wouldn’t work....(read more)

Notes of a discussion over usage of PowerShell vs Bash

chuacw — Fri, 05 Nov 2021 00:09:26 GMT

For me, I’ll choose the best tool to use, and in this case, for me, it is PowerShell. I’ve used bash over many years, and PowerShell only less...(read more)

A self-contained TypeScript library demo

chuacw — Sun, 17 Oct 2021 11:28:00 GMT

In case I forget, I've created a self-contained TypeScript library demo on my Github repo. It's a simple TypeScript project, and very minimal....(read more)

Calling functions dynamically in TypeScript and JavaScript

chuacw — Sun, 03 Oct 2021 07:05:00 GMT

TypeScript functions to determine if a Javascript method exists, and call it via its name, together with the arguments. function functionExists ( funcName...(read more)

Setting up a TypeScript project and debugging it in VSCode

chuacw — Mon, 27 Sep 2021 01:33:00 GMT

One of the things I keep forgetting is how to set up a TypeScript project and debugging it in VSCode. This blog post will remind me how to do so. In a...(read more)

Updating PowerShell help

chuacw — Sat, 28 Aug 2021 05:09:37 GMT

Normally, when you need to update PowerShell's help, you just run the command Update-Help. However, since PowerShell v7, an error has crept in when...(read more)

Querying Bitquery for calls to a smart contract from a specific address

chuacw — Sat, 31 Jul 2021 12:24:01 GMT

Some time ago, I learnt GraphQL, for use on Bitquery , as a way of querying the blockchain for specific transactions that I've initiated to a particular...(read more)

Embarcadero releases RAD Studio 10.4.2 patch

chuacw — Tue, 04 May 2021 10:44:56 GMT

Embarcadero has released patches for the RAD Studio 10.4 product . The patches consist of a compiler patch, a general patch and a RTL patch. These patches...(read more)

How to integrate Node.js with IIS

chuacw — Thu, 25 Mar 2021 08:15:33 GMT

I had the opportunity to work with many Node.js applications in the past, and those applications were generally launched in the general manner. Node appname...(read more)

Random notes on TypeScript

chuacw — Tue, 16 Feb 2021 15:24:00 GMT

How to add properties to existing objects in TypeScript declare global { interface Window { MyNamespace: any; } } window.MyNamespace = window.MyNamespace...(read more)

Javascript IIFE and Delphi IIFE

chuacw — Mon, 08 Feb 2021 03:31:00 GMT

In Javascript, you can define an anonymous function that can be executed immediately. It is called an Immediate Invocation Function Expression, aka IIFE...(read more)

Examples of known blockchain attacks #3: Parity Wallet hack

chuacw — Thu, 04 Feb 2021 13:29:44 GMT

The Parity Wallet hack was an attack performed on 19 Jul 2017, on the 2 Ethereum smart contracts deployed by Parity Techologies . The first Parity smart...(read more)

Examples of known blockchain attacks #2: The DAO re-entrancy hack

chuacw — Sun, 03 Jan 2021 11:47:28 GMT

The Decentralised Autonomous Organisation (DAO) was a smart contract deployed on the Ethereum blockchain network designed to fund blockchain projects and...(read more)

Examples of known blockchain attacks #1: Double-spend attack

chuacw — Wed, 30 Dec 2020 14:00:00 GMT

Inherent to the design of the blockchain is the principle of democracy, that all honest nodes agree upon the longest chain to be the source of truth. As...(read more)

Building the Delphi RTL on mac OSX

chuacw — Thu, 19 Nov 2020 01:03:00 GMT

Release: %BDS%\bin\dccosx64.exe -$C- -$D0 -$L- -CG -H -M -Q -V- -W^ -Z -- no -config -JPHN -W-UNSUPPORTED_CONSTRUCT -W-UNIT_DEPRECATED -W-SYMBOL_DEPRECATED...(read more)

Extending enumerated types with new members...

chuacw — Mon, 09 Nov 2020 11:00:00 GMT

Delphi has an enumerated type since the beginning. I'm sure some of us have from time to time, wonder how to extend an enumerated type, like this developer...(read more)

Reading the properties of a PNG image

chuacw — Wed, 07 Oct 2020 04:31:00 GMT

How do you read and write to the properties of a PNG image? Let the following image show you how....(read more)

Free more space by redirecting the Linux SDKs for your RAD Studio

chuacw — Thu, 03 Sep 2020 09:54:00 GMT

How to free more space on your home drive by redirecting the location for SDKs in RAD Studio

...(read more)

Command line used to compile System.pas in Delphi

chuacw — Thu, 03 Sep 2020 09:49:00 GMT

Learn the command line used to compile System.pas in Delphi

...(read more)

Aligning a record or a native type declared on the stack/heap with Delphi

chuacw — Thu, 06 Aug 2020 01:54:00 GMT

A method to design records so that they're allocated on a specific byte boundary, such as 16 bytes, 512 bytes, 4096 bytes, etc.

...(read more)

A cool thing about Go map

chuacw — Fri, 17 Jul 2020 09:24:00 GMT

Learn why the map is cool in Go!

...(read more)

Speed up your browsing with Firefox!

chuacw — Mon, 15 Jun 2020 14:59:00 GMT

Firefox now has HTTP3! Enable it by setting network.http.http3.enabled to true!...(read more)

NotifyModuleUnload

chuacw — Fri, 05 Jun 2020 23:00:00 GMT

Since Delphi 3, NotifyModuleUnload in the System unit has been written the way it is now. procedure NotifyModuleUnload(HInstance: THandle); var P: PModuleUnloadRec;...(read more)

New plug-ins for RAD Studio Rio 10.3.3 and Sydney 10.4!

chuacw — Thu, 04 Jun 2020 23:16:00 GMT

Over time, I've been building a ToolsAPI library that exposes functionality to making writing RAD Studio plug-ins even easier, since my first plug...(read more)

Blocking an IP for 23 hours

chuacw — Wed, 03 Jun 2020 05:06:00 GMT

One of the issues I have, running a blog site I own, is that there are certain automated entities on the Internet that likes to poll my website every half...(read more)

The genesis for FixAndroidLogger: fixing a RAD Studio mistake.

chuacw — Fri, 29 May 2020 09:11:00 GMT

When FireMonkey became available for Android, one of the things I looked at was how logging was done. The API to Android logging are located in Androidapi...(read more)

Lessons learnt from software development management failures...

chuacw — Thu, 28 May 2020 04:04:00 GMT

There's a lot of lessons to be learnt from observing how product management and development teams fail to manage software products properly. One of...(read more)

When I called you last night from Glasgow...

chuacw — Tue, 31 Mar 2020 08:40:00 GMT

One of the more useful techniques I've developed over the years is detecting what module the caller for a method came from. In an application with...(read more)

Deleting old SQL backup files

chuacw — Mon, 06 Jan 2020 10:00:00 GMT

I recently noticed that my SQL backup files were not getting deleted, and after some research, found the commands to delete old backup files. Xp_delete_file...(read more)

Issues encountered while developing the Packer Builder for the Tencent Cloud

chuacw — Tue, 10 Dec 2019 10:41:00 GMT

These are notes that I've written when I was working on building a Hashicorp Packer Builder plugin in Go. The issue with the development of this Packer...(read more)

RAD Studio 10.3.3 is released, a visible UI bug and a fix.

chuacw — Tue, 03 Dec 2019 14:48:00 GMT

RAD Studio 10.3.3 has been released about 2 weeks ago. I won't go through all the new features, since all these has been covered elsewhere. When you're...(read more)

Scheduling a button press in Javascript

chuacw — Wed, 04 Sep 2019 03:57:00 GMT

Sometimes, if you're away, or out of touch, and you need to click a button on a web page around or after a specific time, you just have no choice but...(read more)

Undocumented class operators in Delphi 10.2

chuacw — Sat, 18 May 2019 07:03:00 GMT

Today, I've discovered new undocumented class operators in the Delphi 10.2 compiler. Since class operators apply on records, these currently apply...(read more)

How any multithreaded FireMonkey Android app can crash

chuacw — Wed, 15 May 2019 00:00:00 GMT

Recently, I found out that any multithreaded Android application written with the FireMonkey framework can crash, if you use the CallInUIThread routine...(read more)

Visual Studio Code on Linux

chuacw — Tue, 14 May 2019 15:07:00 GMT

Nearly 2 years ago, on 14 Sep 2017, I discovered Visual Studio Code, and tried it out. Some time in 2008, I started using it actively to develop code in...(read more)

Detecting the FireMonkey and VCL framework within your code

chuacw — Tue, 14 May 2019 09:43:00 GMT

If you're writing common code that's supposed to work on the FireMonkey and the VCL framework, occasionally, it might be useful to detect whether...(read more)

Firefox extensions/addons got disabled, and how to fix it

chuacw — Sat, 04 May 2019 09:16:00 GMT

Today, nearly every extension and addon in Mozilla Firefox got disabled due to an expired certificate that was used to sign these extensions / addons....(read more)

Enabling even more privacy in your web browsing experience using Encrypted Server Name Indication and DNS over HTTPS

chuacw — Wed, 01 May 2019 07:40:00 GMT

For those of us who always wanted to ensure privacy and security in our browsing experience, we always choose to browse web sites which can provide SSL...(read more)

Fixing the Android Logging mechanism

chuacw — Sun, 28 Apr 2019 05:46:00 GMT

There's an issue with the logging mechanism in FireMonkey I don't like, and that's the tag that was used when you make a call to the Log method...(read more)

A THTTPClient issue with HTTP proxies, and a workaround

chuacw — Thu, 21 Feb 2019 09:48:00 GMT

The development of the JSON RPC framework started on 10th Feb. I was inspired by the QP report that I've filed last year, and developed the JSON RPC...(read more)

How the SCP protocol works

chuacw — Mon, 04 Feb 2019 03:16:00 GMT

Have you ever wondered how the scp and rcp commands worked? The first time I did I haven't found any documentation on the subject. There is no RFC...(read more)

Dumping field names and offset

chuacw — Sun, 27 Jan 2019 13:59:00 GMT

Given there's a single type declaration, THDItem and that I wanted to see the field offsets as well as calculate the total size of the record, using...(read more)

A custom built Terraform File System Provider

chuacw — Sun, 20 Jan 2019 04:02:00 GMT

While working on building blockchain node infrastructure, one of the tools I used is Terraform . The built-in providers in Terraform didn't allow me...(read more)

Achievement 2018!

chuacw — Sat, 15 Dec 2018 03:44:00 GMT

I've never placed much emphasis on achievements, so much so that whenever I was asked about my achievements during job interviews, I tend to be unable...(read more)

A technical description of AWS Lambda

chuacw — Tue, 30 Oct 2018 01:58:00 GMT

An AWS Lambda is a function that runs on servers. It can be configured either to run inside the VPC, or on AWS servers. No matter what, the server on which...(read more)

Importing and deleting Terraform resources

chuacw — Mon, 08 Oct 2018 09:37:00 GMT

After changing the Terraform files by hand, I realized that I have Terraform resources created on AWS. But I can't do a terraform destroy -auto-approve...(read more)

The Journey so far...

chuacw — Sun, 07 Oct 2018 02:55:00 GMT

This year, I've done some very interesting consulting work. Here's what was done: Fixed memory leaks and made improvements to a commercial Delphi...(read more)

Flashing OpenWRT 18.06.1 using both Windows and a macOS

chuacw — Fri, 24 Aug 2018 00:12:00 GMT

OpenWRT 18.06.1 was released recently, and I took the opportunity to upgrade my router. Gotcha: Flashing from the LuCI page: Uncheck the "Keep settings"...(read more)

Odd application termination issue, and an unlikely fix

chuacw — Mon, 13 Aug 2018 13:09:00 GMT

One of the rarest moments I have with regards to applications are the fact that Mercury, the SMTP application, and another application I shall not name...(read more)

Upgrading all OpenWRT packages in one line

chuacw — Thu, 24 May 2018 16:46:00 GMT

Here's how to check and upgrade all your OpenWRT packages in one line opkg update && opkg upgrade `opkg list-upgradable | awk '{print ...(read more)

Initializing structs in Go

chuacw — Wed, 23 May 2018 16:51:00 GMT

In Go, there are a few ways to initialize a new struct. You can do this: varStruct := &StructName{} varStruct := StructName{} varStruct := StructName...(read more)

Declaring and assigning variables in Go

chuacw — Mon, 14 May 2018 06:10:00 GMT

There's multiple ways of declaring a variable in Go. You can do this: var VarName TypeName So, for example, var s string declares a variable s with...(read more)

Multithreading in C# and Delphi

chuacw — Sat, 12 May 2018 05:59:00 GMT

Even when you think you understand multithreading well enough, there's some games you'll find interesting. The Deadlock Empire are games in C#...(read more)

Learning Golang, aka Go

chuacw — Mon, 30 Apr 2018 07:18:00 GMT

I've been learning a new language, Golang, created by Google, also known as Go. I got fascinated by the language some time ago, and when I saw dnscrypt...(read more)

Making your DNS queries private for your entire network

chuacw — Thu, 19 Apr 2018 03:15:00 GMT

In my previous post, " Making your web browsing experience even more private! ", I shared how to encrypt your DNS queries on the browser level...(read more)

Site transition to SSL is completed!

chuacw — Thu, 12 Apr 2018 14:05:00 GMT

Over two and a half years ago, when Let's Encrypt launched their free SSL certificate services, I signed up to them, generating a SSL certificate for...(read more)

Making your web browsing experience even more private!

chuacw — Tue, 03 Apr 2018 13:30:00 GMT

Cloudflare recently launched a faster way of looking up domain names , much faster than Google. In partnership with Cloudflare, Firefox added a new way...(read more)

Reverse engineering the Web3 API

chuacw — Sat, 03 Mar 2018 13:45:00 GMT

I've been working on the Web3 API for quite a while now. The JSON RPC protocol is documented here and the Web3 API is documented here , however, there...(read more)

Automatically renewing Let's Encrypt™ SSL and binding it to a web site

chuacw — Tue, 20 Feb 2018 14:10:00 GMT

Let's Encrypt ™ is a SSL certificate issuing authority that started around Jun 2015. It went into beta sometime around the last quarter of 2015...(read more)

The mechanics of an ICO - how to do a crowdsale

chuacw — Mon, 19 Feb 2018 06:31:00 GMT

How do you do a crowdsale, or raise an ICO? Get your whitepaper written and reviewed by a legal entity, such as the Blockchain Advisory Council , or the...(read more)

Something to ponder: using interfaces with class type variables

chuacw — Tue, 13 Feb 2018 03:28:00 GMT

One of the issues I've encountered recently is code like this: type ISomeIntf = interface procedure SomeMethod; end; TSomeClass = class(TInterfacedObject...(read more)

How to write Truffle scripts to test your Solidity contracts automatically

chuacw — Wed, 31 Jan 2018 12:01:00 GMT

Every Truffle script is a Javascript app. So, if you're familiar with writing Javascript, you already know how to write a Truffle script. How do you...(read more)

Retrieving blocked attachments from Google with Delphi

chuacw — Mon, 01 Jan 2018 15:30:00 GMT

So, I was looking at an old email, and there was an attachment. Unfortunately, Google's Gmail had blocked the attachment, thinking it had a virus attached...(read more)

Automated clicking on HTML elements

chuacw — Fri, 15 Dec 2017 01:36:00 GMT

On a HTML page, elements can be retrieved either by using the getElementsByClassName or the getElementById method. The getElementById method returns just...(read more)

Persisting enumeration and sets to JSON

chuacw — Mon, 11 Dec 2017 08:01:00 GMT

I've created a demo on persisting enumeration and sets to JSON format. The default Delphi RTL persists enumeration as their names. The improvement...(read more)

Why you need to make your string parameter a const

chuacw — Fri, 08 Dec 2017 01:40:00 GMT

I have often wanted to point this out, but didn't really feel the need to, until today, when I was debugging into the RTL. When you have a string parameter...(read more)

How to install Ganache

chuacw — Thu, 16 Nov 2017 07:56:00 GMT

The latest Ethereum tool, is Ganache, an one-click Blockchain. It's distributed in appx format, which apparently, is only supported by Windows 10....(read more)

Removing custom contracts and tokens

chuacw — Mon, 13 Nov 2017 13:55:00 GMT

Here's how to remove custom contracts and tokens in Ethereum Wallet / Mist Open up the Wallet UI For tokens: run this command in the console: Tokens...(read more)