We will build a web application that supports local db synced with remote db. This post is a continuation from the previous post: How to Build WatermelonDB Sync Backend in Elixir.
WatermelonDB is a reactive database for React frontend application that supports data synchronization.
What I like about this database is you can bring your own sync backend (HTTP-based) as long as it complies with this spec:
| Operation | Request Params / Body | Response Body |
|---|---|---|
| Pull | - lastPulledAt: integer, Unix time in milliseconds (ms) | - changes: (JSON) - timestamp: integer, Unix time in milliseconds (ms) |
| Push | - changes: (JSON) - lastPulledAt: integer, Unix time in milliseconds (ms) | X |
The following is a brief how pull and push operation works. Please refer to Sync documentation for the details
The idea is simple. Sequential UUIDv4 (128 bit) consists of unix timestamp (32 bit) + random bytes (96 bit)
Recently, I am making a simple Elixir application performing some actions to a website in an automated way.
The automated testing tool is a perfect candidate to be used to help to build application like that. I use Hound as browser automation library and Chrome as a controlled browser. For the browser driver, I use ChromeDriver.
Pomera DM100 is a distraction-free digital writing tool. Think mini laptop with only text editor application loaded.
It comes from Japan. It means its manual is in all Japanese. It becomes hard when you want to do the crucial procedure (like upgrading firmware) AND Google Translate doesn't help you much.
I can only follow some steps in its updating guide web page and the rest of important steps in PDF are not translatable by Google Translate.
In the end, I have successfully updated my Pomera DM100 to the latest firmware.
Here are the steps:
Required dependencies (pom.xml) :
<dependency>
<groupId>com.ibm.icu</groupId>
<artifactId>icu4j</artifactId>
<version>60.1</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.6</version>
</dependency>
Autodetect the charset encoding of a text file or input stream then 'remove' (skip) Byte Order Mark (BOM) while reading based on detected charset :
File inputFile = new File("/Users/fahri/Downloads/UNKNOWN_TEXT.txt");
BOMInputStream bomInputStream = new BOMInputStream(new BufferedInputStream(new FileInputStream(inputFile)),
ByteOrderMark.UTF_8, ByteOrderMark.UTF_16BE, ByteOrderMark.UTF_16LE, ByteOrderMark.UTF_32BE, ByteOrderMark.UTF_32LE);
System.out.println("HAS BOM : " + bomInputStream.hasBOM());
CharsetDetector detector = new CharsetDetector();
detector.setText(bomInputStream);
CharsetMatch charsetMatch = detector.detect();
System.out.println("CHARSET MATCH : " + charsetMatch.getName());
BufferedReader br = new BufferedReader(new InputStreamReader(bomInputStream, charsetMatch.getName()));
for (String line = br.readLine(); line != null; line = br.readLine()) {
System.out.println(line);
}
br.close();
$ docker pull wnameless/oracle-xe-11g
$ docker run -d -p 1022:22 -p 1521:1521 -e ORACLE_ALLOW_REMOTE=true wnameless/oracle-xe-11g
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
4fe7a1024ed3 wnameless/oracle-xe-11g "/bin/sh -c '/usr/..." 5 weeks ago Exited (137) 4 days ago practical_williams
$ docker start practical_williams
# or
$ docker start 4fe7a1024ed3
Create two repositories on Github:
hugo new site): https://github.com/fahrinh/my-siteCreate a Personal Access Token at https://github.com/settings/tokens with the repo scope. Copy the token to your clipboard.
Make sure there is a CNAME file containing the custom domain in the https://github.com/fahrinh/my-site repository.
class HelloWorld {
static public void main( String args[] ) {
System.out.println( "Hello World!" );
}
}
fun main(args : Array<String>) {
println("Hello, world!")
}
console.log("Hello World");
defmodule HelloWorld do
IO.puts "Hello, World!"
end
package main
import "fmt"
func main() {
fmt.Printf("Hello World\n")
}