wiki

Node js export and import

In the first part I am explaining how to do export and import using js.

here is my sample module ‘myutile.js‘

const myMethod1 = () => {
    console.log('Hi 1')
}
 
const myMethod2 = () => {
    console.log('Hi 2')
}

const myData = {
    name:'myname',
    age:22
}

module.exports = {
    myMethod1, 
    myMethod2,
    myData
};

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const myMethod1 = () => {

console.log('Hi 1')

}

const myMethod2 = () => {

console.log('Hi 2')

}

const myData = {

name:'myname',

age:22

}

module.exports = {

myMethod1,

myMethod2,

myData

};

we can import all from the above module

var access1 = require('./myutile');

access1.myMethod1();

access1.myMethod2();

console.log(access1.myData);

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var access1 = require('./myutile');

access1.myMethod1();

access1.myMethod2();

console.log(access1.myData);

output:

And also we can import only the specific function/data . for example I need to import only the myMethod2() and myData from the module

var m2 = require('./myutile').myMethod2;
var data = require('./myutile').myData;

m2();

console.log(data);

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var m2 = require('./myutile').myMethod2;

var data = require('./myutile').myData;

m2();

console.log(data);

output:

Using Typescript

sample module ‘myutile.js’

export const myMethod1 = () => {
    console.log('Hi 1')
}

export const myMethod2 = () => {
    console.log('Hi 2')
}

export const myData = {
    name: 'myname',
    age: 22
}

export default {
    myMethod1,
    myMethod2,
    myData
};

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export const myMethod1 = () => {

console.log('Hi 1')

}

export const myMethod2 = () => {

console.log('Hi 2')

}

export const myData = {

name: 'myname',

age: 22

}

export default {

myMethod1,

myMethod2,

myData

};

Importing all

import allUtiles from './myutile';

allUtiles.myMethod1();

allUtiles.myMethod2();

console.log(allUtiles.myData);

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import allUtiles from './myutile';

allUtiles.myMethod1();

allUtiles.myMethod2();

console.log(allUtiles.myData);

output

Importing all

import * as allUtiles  from './myutile';

allUtiles.myMethod2();

allUtiles.myMethod1();

console.log(allUtiles.myData);

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import * as allUtiles from './myutile';

allUtiles.myMethod2();

allUtiles.myMethod1();

console.log(allUtiles.myData);

output

Importing required

import {myMethod1,myData} from './myutile';

myMethod1();

console.log(myData);

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import {myMethod1,myData} from './myutile';

myMethod1();

console.log(myData);

By bm on November 14, 2018 | NodeJs | A comment?
Tags: export, import, module, Nodejs

node js write large data to excel

In this sample I am using a node module called ‘ ExcelJS‘. This will stream the data to the file instead of big data in memory (if we are keeping large amount of data in memory, we may get JavaScript heap out of memory exception ) this will write to the file

Install the module using npm

npm install exceljs --save

1	npm install exceljs --save

then in the node application just import the module

const Excel = require('exceljs');

const options = {
  filename: 'myfile.xlsx',
  useStyles: true,
  useSharedStrings: true
};

const workbook = new Excel.stream.xlsx.WorkbookWriter(options);

const worksheet = workbook.addWorksheet('my sheet');

worksheet.columns = [
    { header: 'Id', key: 'id' },
    { header: 'First Name', key: 'first name' },
    { header: 'Phone', key: 'ph' }
]

var data;

for(let i = 1; i<= 10; i++){
  
  data = {
    id: i,
    'first name': "name "+i,
    ph: "012014520"+i
  };

  worksheet.addRow(data).commit();
}

workbook.commit().then(function() {
  console.log('excel file cretaed');
});

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const Excel = require('exceljs');

const options = {

filename: 'myfile.xlsx',

useStyles: true,

useSharedStrings: true

};

const workbook = new Excel.stream.xlsx.WorkbookWriter(options);

const worksheet = workbook.addWorksheet('my sheet');

worksheet.columns = [

{ header: 'Id', key: 'id' },

{ header: 'First Name', key: 'first name' },

{ header: 'Phone', key: 'ph' }

]

var data;

for(let i = 1; i<= 10; i++){

data = {

id: i,

'first name': "name "+i,

ph: "012014520"+i

};

worksheet.addRow(data).commit();

}

workbook.commit().then(function() {

console.log('excel file cretaed');

});

we can use the same module in typescript also

refer : exceljs

By bm on October 18, 2018 | Uncategorized | A comment?

Codeigniter create custom config

Create config file in ‘application\config’ folder, give any name (for example I have given ‘cust_settings.php’ [application\config\cust_settings.php] )

<?php  
if (!defined('BASEPATH')) exit('No direct script access allowed');


$config['site_name'] = 'My website';
$config['protocol'] = 'smtp';
$config['smtp_host'] = 'smtp1.server.com';
$config['smtp_user'] = 'username';
$config['smtp_pass'] = 'password';
$config['smtp_port'] = '25';

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<?php

if (!defined('BASEPATH')) exit('No direct script access allowed');

$config['site_name'] = 'My website';

$config['protocol'] = 'smtp';

$config['smtp_host'] = 'smtp1.server.com';

$config['smtp_user'] = 'username';

$config['smtp_pass'] = 'password';

$config['smtp_port'] = '25';

You can use ‘config->load()’ function to load the configuration and ‘$this->config->item()’ to retrieve the configuration values

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Welcome extends CI_Controller {

	public function index()
	{
		

		// Loads a config file named cust_settings.php and assigns it to an index named "cust_settings"
		$this->config->load('cust_settings', TRUE);

		// Retrieve a config item named site_name contained within the cust_settings array
		$site_name = $this->config->item('site_name', 'cust_settings');

		echo $site_name."<br><br>";

		// An alternate way to specify the same item:
		$cust_settings = $this->config->item('cust_settings');
		
		//$site_name = $cust_settings['site_name'];

		echo "<pre>";
		print_r($cust_settings);
		echo "</pre>";

                $this->load->view('welcome_message');


	}
}

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<?php

defined('BASEPATH') OR exit('No direct script access allowed');

class Welcome extends CI_Controller {

public function index()

{

// Loads a config file named cust_settings.php and assigns it to an index named "cust_settings"

$this->config->load('cust_settings', TRUE);

// Retrieve a config item named site_name contained within the cust_settings array

$site_name = $this->config->item('site_name', 'cust_settings');

echo $site_name."<br><br>";

// An alternate way to specify the same item:

$cust_settings = $this->config->item('cust_settings');

//$site_name = $cust_settings['site_name'];

echo "<pre>";

print_r($cust_settings);

echo "</pre>";

$this->load->view('welcome_message');

}

Output

For using this we can load multiple configuration files

ref: codeigniter.com

By bm on January 24, 2018 | codeigniter | A comment?

SQL getting items not in a list

In the bellow example, getting list of person id not exist in the given list

SELECT E.person_id
FROM (VALUES
(661),
(1826),
(2036),
(2567),
(2922),
(3408)
) E(person_id)
WHERE NOT EXISTS
(
    SELECT 1
    FROM persontable P 
    WHERE E.person_id = P.id
)

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SELECT E.person_id

FROM (VALUES

(661),

(1826),

(2036),

(2567),

(2922),

(3408)

) E(person_id)

WHERE NOT EXISTS

(

SELECT 1

FROM persontable P

WHERE E.person_id = P.id

)

For strings (varchars)

SELECT E.email
FROM (VALUES
('email1@test.com'),
('email2@test.com'),
('email3@test.com'),
('email4@test.com')
) 
E(email)
WHERE NOT EXISTS
(
    SELECT 1
    FROM person P 
    WHERE E.email = P.emailid
)

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SELECT E.email

FROM (VALUES

('[email protected]'),

('[email protected]')

)

E(email)

WHERE NOT EXISTS

(

SELECT 1

FROM person P

WHERE E.email = P.emailid

)

tested in PostgreSQL

By bm on September 1, 2017 | postgresql, SQL | A comment?

Enable session WordPress

Add the following code in function.php to enable or start session in wordpress

add_action('init', 'activate_session', 1);

function activate_session() {
    if(!session_id()) {
        session_start();
    }
}

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add_action('init', 'activate_session', 1);

function activate_session() {

if(!session_id()) {

session_start();

}

By bm on August 30, 2017 | php, wordpress | A comment?

Create a basic java spring boot application

This is a basic example for beginners for creating a basic java spring boot application using ‘spring-boot-starter-parent’.

In this tutorial I am using Spring tool suite as my IDE.

Step I. Create a Maven project

I.1: File->New -> Maven Project (You can do it by write clicking in the blank space of Package Explorer )

I.2: I have selected ‘create a simple project ( skip archetye selection)’ this allow me to kip the Archetype selection

I.3 : Setting group id and artifact id and other project related details

Done with the maven project creation, you can see the IDE automatically create the project folder structure like bellow .

You can see the project details in pom.xml file

Add the spring boot dependency

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.mytutor</groupId>
	<artifactId>my-project</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>My Project</name>
	<description>some description</description>

	<properties>
		<java.version>1.8</java.version> <!-- Setting java version -->
	</properties>
	
	<parent> <!-- here we are saying our project is a child of the  spring-boot-starter-parent project -->
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.3.RELEASE</version>
	</parent>

	<dependencies>
		<dependency> <!-- Adding spring boot dependency -->
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		
         </dependencies>

</project>

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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

<groupId>com.mytutor</groupId>

<artifactId>my-project</artifactId>

<version>0.0.1-SNAPSHOT</version>

<name>My Project</name>

<description>some description</description>

<java.version>1.8</java.version>

</properties>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-parent</artifactId>

<version>1.5.3.RELEASE</version>

</parent>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-web</artifactId>

</dependency>

</dependencies>

</project>

Update the project

write click on project folder->Maven->Update Project

After update we can see JRe updated to 1.8 and added Maven Dependencies

Now we can create our application entry point

Crate a class like bellow (sselect the tic ‘public static void main’ to auto generate the function)

Right click in Package Explorer -> New ->Class

Then add @SpringBootApplication annotation to the class and add SpringApplication.run(MyApp.class, args); inside the main function

package com.mytutor;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MyApp {

	
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		SpringApplication.run(MyApp.class, args);
	}

}

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package com.mytutor;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

public class MyApp {

public static void main(String[] args) {

// TODO Auto-generated method stub

SpringApplication.run(MyApp.class, args);

}

Now we can create our controller

Right click in Package Explorer -> New ->Class

Add the following code in the file

package com.mytutor.controllers;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MyFirstController {
	
	@RequestMapping("/home")     //Request mapping https://localhost/home
    String myHome() {
        return "Hello World!";
    }

}

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package com.mytutor.controllers;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class MyFirstController {

@RequestMapping("/home") //Request mapping https://localhost/home

String myHome() {

return "Hello World!";

}

You are done

Now we can run our application You can press the Green *Play button Or you can right click the project folder and select the Run As – >Java Application

Tadaaaaa! Our project is running

Now we can hit the url

We and run Spring boot application from command line also by using the command mvn spring-boot:run

Done

Note

If you are getting the error “Exception in thread “main” java.lang.NoClassDefFoundError: ch/qos/logback/classic/turbo/TurboFilter ” please add the logback-classic dependency in pom file

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		
		<!-- Exception in thread "main" java.lang.NoClassDefFoundError: ch/qos/logback/classic/turbo/TurboFilter  -->
		<!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-classic -->
		<dependency>
		    <groupId>ch.qos.logback</groupId>
		    <artifactId>logback-classic</artifactId>
		    <version>1.2.3</version>
		    <scope>test</scope>
		</dependency>

	</dependencies>

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<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-web</artifactId>

</dependency>

<groupId>ch.qos.logback</groupId>

<artifactId>logback-classic</artifactId>

</dependency>

</dependencies>

By bm on July 19, 2017 | Java, Spring boot | A comment?
Tags: Beginners, Java, Spring Boot

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wiki - workassis

Node js export and import

Importing all

Importing all

Importing required

node js write large data to excel

Codeigniter create custom config

SQL getting items not in a list

SQL getting items not in a list

For strings (varchars)

Enable session WordPress

Enable session WordPress

Create a basic java spring boot application

Step I. Create a Maven project

Add the spring boot dependency

Update the project