アプリ関連ニュース

I would like to talk about the date filtering process I am using in laravel today.

If we want to select records that is created today. We can normally use raw queries or without raw queries like this.

//Raw Query
Model::where(DB::raw("DATE(created_at) = '".date('Y-m-d')."'"))->get();

//Not Raw Query
Model::where('created_at', '>=', date('Y-m-d').' 00:00:00'))->get();

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//Raw Query

Model::where(DB::raw("DATE(created_at) = '".date('Y-m-d')."'"))->get();

//Not Raw Query

Model::where('created_at', '>=', date('Y-m-d').' 00:00:00'))->get();

In fact, we can do more neat and eloquent way in laravel like this.

Model::whereDate('created_at', '=', date('Y-m-d'))->get();

1	Model::whereDate('created_at', '=', date('Y-m-d'))->get();

We can also use Carbon function instead of date(), result will still the same.

Model::whereDate('created_at', '=', Carbon::today()->toDateString())->get();

1	Model::whereDate('created_at', '=', Carbon::today()->toDateString())->get();

If you want to filter just not with full date, it’s totally fine. You can filter with day, month and year like this.

//Day
Model::whereDay('created_at', '=', date('d'))->get();
//Month
Model::whereMonth('created_at', '=', date('m'))->get();
//Year
Model::whereYear('created_at', '=', date('Y'))->get();

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//Day

Model::whereDay('created_at', '=', date('d'))->get();

//Month

Model::whereMonth('created_at', '=', date('m'))->get();

//Year

Model::whereYear('created_at', '=', date('Y'))->get();

There is also another method called whereBetween if you want to filter by date range.

Model::whereBetween('created_at', [FROM_DATE, TO_DATE])->get();

1	Model::whereBetween('created_at', [FROM_DATE, TO_DATE])->get();

By Yuuma

PCにインストール可能なRaspberryPi用のOS(Raspberry Pi Desktop for PC)があります。
今回はこのOSを VirtualBox上の仮想PC にインストールしてみます。

Today I would like to make a short introduction about dry code.

What is dry code

There is a principle in programming called DRY, or Don’t Repeat Yourself. It usually means refactoring your code by taking something done multiple times and turning it into a loop or a function. The DRY code is easy to change, because you only have to make any changes in one place.

Advantages of DRY

Maintainability

The biggest benefit of using DRY is ease of maintenance. If the logic of checking permissions was repeated throughout the code, it is difficult to troubleshoot problems that occur in the repeated code. When you fix a problem in one, you can easily forget to fix the problem in other cases. Also, if you have to modify the logic, you have to copy and paste everywhere. By having non-repeating code, you just have to keep the code in one place. New bug and logic fixes can be made in one place instead of many. This leads to robust and reliable software.

Readability

Most of the time, the DRY code is more readable. This is not due to the DRY principle itself, but rather the extra effort that the developer put into the code to make it follow certain principles like DRY.

Re-use

DRY inherently promotes code reuse because we are merging 2 or more instances of repeating code into a single code block. Reusable code pays off in the long run as it speeds up development time.

Cost

If management needs to be convinced to spend more time improving code quality, this is it. More code costs more. More code requires more time to maintain and fix bugs. More time to develop and more mistakes leads to a very unhappy customer.

Tests

We are talking about unit testing and integration testing here, not manual testing. The more routes and functions you have to cover with the tests, the more code you will have to write for the tests. If your code doesn’t repeat, you just have to test one parent path.

By Yuuma.

Androidのカメラ制御は
カメラが対応している解像度の取得や
プレビュー解像度の設定、画面回転など
いくつか面倒なステップを踏む必要がありますが
それらを吸収してくれる公式ライブラリがCameraXです。

ライブラリの使用方法はGoogleのCameraXのドキュメントに記載されていますが、
実際に動かしてみたコードを以下に記載します。
MainActivityにカメラプレビューを表示するだけの機能を持つアプリです。

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.camera.core.CameraSelector
import androidx.camera.core.Preview
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.view.PreviewView
import androidx.core.content.ContextCompat
import androidx.lifecycle.LifecycleOwner
import com.google.common.util.concurrent.ListenableFuture

class MainActivity : AppCompatActivity() {
    private lateinit var cameraProviderFuture: ListenableFuture<ProcessCameraProvider>
    private lateinit var previewView : PreviewView
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // PreviewView
        previewView = findViewById(R.id.cameraPreview)

        // CameraProvider リクエスト
        cameraProviderFuture = ProcessCameraProvider.getInstance(this)

        // タスクを実行するエグゼキューター
        val executor = ContextCompat.getMainExecutor(this)

        // リスナー用タスク
        val listenerRunnable = Runnable {
            // ListenableFutureからCameraProviderを取得
            val cameraProvider = cameraProviderFuture.get()
            // ライフサイクルにバインド　-カメラの指定とプレビューの設定も行う
            bindToLifecycle(cameraProvider)
        }

        // CameraProvider リクエスト のリスナーをセット
        cameraProviderFuture.addListener(listenerRunnable, executor)
    }

    private fun bindToLifecycle(cameraProvider: ProcessCameraProvider)
    {
        // Previewを作成
        val preview : Preview = Preview.Builder().build()
        // 背面カメラを選択
        val cameraSelector : CameraSelector = CameraSelector.Builder()
            .requireLensFacing(CameraSelector.LENS_FACING_BACK)
            .build()
        // Previewとレイアウト上のPreviewViewを接続
        preview.setSurfaceProvider(previewView.surfaceProvider)

        // CameraProvider をライフサイクルにバインド
        val camera = cameraProvider.bindToLifecycle(this as LifecycleOwner, cameraSelector, preview)
    }
}

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import androidx.appcompat.app.AppCompatActivity

import android.os.Bundle

import androidx.camera.core.CameraSelector

import androidx.camera.core.Preview

import androidx.camera.lifecycle.ProcessCameraProvider

import androidx.camera.view.PreviewView

import androidx.core.content.ContextCompat

import androidx.lifecycle.LifecycleOwner

import com.google.common.util.concurrent.ListenableFuture

class MainActivity : AppCompatActivity() {

private lateinit var cameraProviderFuture: ListenableFuture<ProcessCameraProvider>

private lateinit var previewView : PreviewView

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

setContentView(R.layout.activity_main)

// PreviewView

previewView = findViewById(R.id.cameraPreview)

// CameraProvider リクエスト

cameraProviderFuture = ProcessCameraProvider.getInstance(this)

// タスクを実行するエグゼキューター

val executor = ContextCompat.getMainExecutor(this)

// リスナー用タスク

val listenerRunnable = Runnable {

// ListenableFutureからCameraProviderを取得

val cameraProvider = cameraProviderFuture.get()

// ライフサイクルにバインド　-カメラの指定とプレビューの設定も行う

bindToLifecycle(cameraProvider)

}

// CameraProvider リクエストのリスナーをセット

cameraProviderFuture.addListener(listenerRunnable, executor)

}

private fun bindToLifecycle(cameraProvider: ProcessCameraProvider)

{

// Previewを作成

val preview : Preview = Preview.Builder().build()

// 背面カメラを選択

val cameraSelector : CameraSelector = CameraSelector.Builder()

.requireLensFacing(CameraSelector.LENS_FACING_BACK)

.build()

// Previewとレイアウト上のPreviewViewを接続

preview.setSurfaceProvider(previewView.surfaceProvider)

// CameraProvider をライフサイクルにバインド

val camera = cameraProvider.bindToLifecycle(this as LifecycleOwner, cameraSelector, preview)

}

Kotlinで書いているのもありますが、
ライブラリを使用しない時と比べて、ぐっと必要なコード量が減っています。

画像の撮影や、画像分析もライブラリに含まれているようです。

水曜担当：Tanaka

Pseudocode is an informal form of programming description that does not require any strict programming language syntax or underlying technology considerations. Used to create an outline or draft of a program. Pseudocode summarizes the flow of a program, but excludes the underlying details. Systems designers write pseudocode to ensure that programmers understand the requirements of a software project and align the code accordingly.

A Pseudocode is a prototype sample, model, or early release of a product created for the purpose of testing concepts and for learning purposes. They help us learn without fully implementing our solutions. When developing user interfaces for our applications, we have several prototypes before the final interface. Some examples of these are wire frames, graphic designs, and mockups.

This is the way how to write pseudo code.

Organize your task sequence and write your pseudocode accordingly.
Start with the declaration of a pseudocode that states the main goal or goal.

We have to know there are some KEYWORDS to be used in pseudo code.
These are for start and end of a program
BEGIN, END

These are for condition statements.
IF, ELSE, ENDIF, DO, WHILE, ENDWHILE, REPEAT, UNTIL, CASE

These are for user inputs.
INPUT, GET, READ , SET

These are for displaying results.
PRINT, SHOW

Here is some sample pseudo codes.

//Conditional statement if
if "1"
    print "this is 1"

if "2"
    print "this is 2"

//Case condition
INPUT number
CASE number of
    1: PRINT "1"
    2: PRINT "2"
    3: PRINT "3"
DEFAULT
    PRINT "0"
ENDCASE

//While Loop
Set index to 0
WHILE index is GREATER THAN 1
	PRINT index
	INCREASE index BY 1 
END

Function
Function sample
  PRINT 'hello world'
Endfunction

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//Conditional statement if

if "1"

print "this is 1"

if "2"

print "this is 2"

//Case condition

INPUT number

CASE number of

1: PRINT "1"

2: PRINT "2"

3: PRINT "3"

DEFAULT

PRINT "0"

ENDCASE

//While Loop

Set index to 0

WHILE index is GREATER THAN 1

PRINT index

INCREASE index BY 1

END

Function

Function sample

PRINT 'hello world'

Endfunction

There are still more keywords and syntax structures of writing pseudo codes but I think you will get the idea by reading this blog.

By Yuuma

開発スタッフがアプリ関連の最新技術やニュースをご紹介します。

ギガスジャパン

お問い合わせ

Laravel Date Filtering

ラズベリーパイOSをPC上で動かしてみました

Dry code

What is dry code

Advantages of DRY

Maintainability

Readability

Re-use

Cost

Tests

AndroidのカメラサポートライブラリのCameraXを使ってみました

Pseudocode

アプリ関連ニュース

iPhone・Android開発アプリ

アプリ関連ニュース

お問い合わせはこちら

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