janusha: June 2017

Wednesday, June 14, 2017

14/06/2017

1.Create free code camp account.

2.Create trello account.

3.create slack account.

13/06/2017

API

☺HTTP - Hyper Text Transfer Protocol.

Rules are transferring web pages to your browser.

☺Example for URL :

http://www.codecadamy.com

☺The web pages come from other computers on the Internet called servers.

☺REST - REpresentational State Transfer.

Set of principles.

☺API - Application Programming Interface.

☺API do,

1.Separate the client from the server.

2.Not hold state between requests.

3.Use HTTP.

☺xhr stands for XML HTTP Request.

☺Four HTTP verbs

1.GET - Information receives from the source.

2.POST - Sends new information to the specified source.

3.PUT - Updates existing information of the specified source.

4.DELETE - Removes existing information from the specified source.

☺Three parts of HTTP request.

1.Request lines - which tells the server what kind of request is being sent (GET, POST, etc.) and what resource it's looking for.

2.Header - which sends the server additional information (such as which client is making the request).

3.Body - which can be empty or contain data and information.

☺HTTP status codes

1xx: working on the request.

2xx: successfully

3xx: the server might have to reroute the request before it can get you the resource you asked for.

4xx: "file not found".(user problem)

5xx: can't successfully respond to your request.(server problem)

☺HTTP response code

1.Response line: which includes the three-digit HTTP status code.

2.Header: which includes further information about the server.

3.Body: which includes further information about the server

☺XML : Extensible Markup Language.

It is very similar to HTML.

Monday, June 12, 2017

12/06/2017

SASS

❤Functions and operations

1.color values.

2.Apply styles.

3.Assign values (math operations).

4.Iterate on lists and maps.

❤fade-out

changes a color by decreasing opacity.

❤fade-in

changes a color by increasing opacity.

❤Example

$color2 : fade-out($color,$amount);

❤SASS arithmetic operations

1.addition +

2.subtraction -

3.multiplication *

4.division /

5.module % (remainder)

❤Units are compatible in SASS.[we can not multiply pixels by ems]

❤In regular math, multiplying two units together results in squared units.(10px*10px=100px*px)

❤So,we would need to multiply 10px*10=100px.

❤For loop

@for $i from $begin through $end {
//some rules and or conditions
}

❤We can use through or to.

.lemonade {
border: 1px yellow;
background-color: #fdd;
}

.strawberry {
@extend .lemonade;
border-color: pink;
}

❤@extend is working to apply the .lemonade rules to .strawberry.

❤ % (place holder) → extend

❤Mixin deal with arguments.
❤Place holder don't deal with arguments.

Sunday, June 11, 2017

09/06/2017

SASS

Sass can solve the common repetition and maintenance challenges present in traditional CSS.

compile it to CSS by typing the following command in the terminal and pressing enter


sass main.scss main.css



Nesting



Nesting is the process of placing selectors

inside the scope of another selector.



In css





.parent {
  color: blue;
}

.parent .child {
    font-size: 12px;
}

In scss

.parent {
  color: blue;
  .child {
    font-size: 12px;
  }
}

In Sass, $ is used to define and reference

a variable.

Data types of SASS

1.Map

2.List

3.Number

4.String

5.Boolean

6.Null


Strings of text, with and without quotes.

  Examples: "janusha", 'janusha', janusha.

Lists can be separated by either spaces or

commas(don't need []).

     em Helvetica bold;

     Helvetica, Arial, sans-serif;

08/06/2017

LEARN RESPONSIVE DESIGN

Sizing elements

Pixels are used to size content to exact dimensions(px).

create relatively-sized content is the em, written as em in CSS.

The second relative unit of measurement in CSS is the rem, coded as rem.

min-width — ensures a minimum width for an element

.max-width — ensures a maximum width for an element.

05/06/2017

1.Created a worst website.

2.Presentation about worst website.

3.Changed it a best website.

4.Presentation about the best website.

26/05/2017

JSON Datatypes

string
a number
an object (JSON object)
an array
a boolean

null

JSON values cannot be one of the following data types:

a function
a date
undefined

JSON Strings

JSON strings must be written in double quotes.

JSON Numbers

JSON numbers must be an integer or a floating point.

JSON Objects

{
"student":{ "name":"Janusha", "age":19, "city":"Jaffna" }
}

JSON Arrays

{
"student":[ "Janusha", "Karunya", "Poomika" ]
}

JSON Booleans

JSON booleans can be true/false.

{ "sale":true }

JSON Null

{ "middlename":null }

25/05/2017

JSON

What is JSON?

JSON stands for JavaScript Object Notation.
JSON is a syntax for storing and exchanging data.
JSON is text, written with JavaScript object notation.
JSON is "self-describing" and easy to understand.
JSON is language independent *

JSON syntaxs

Data is in name/value pairs.
Data is separated by commas.
Curly braces hold objects.
Square brackets hold arrays.

JSON Data

JSON data is written as name and value pairs.

Name and value pair consists of a field name in double quotes, followed by a colon, followed by a value:
"name":"janusha"

JSON Files

The file type for JSON files is ".json".

24/05/2017

DROP

Use the drop() method to delete a table, or collection.

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
db.collection("studentsdetails").drop(function(err, delOK) {
    if (err) throw err;
    if (delOK) console.log("Table deleted");
    db.close();
});
});

UPDATE

Use the update() method to update records, or documents.

You can update multi options.

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://127.0.0.1:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
var myquery = { address: "Jaffna" };
var newvalues = { name: "Mala", address: "Colombo" };
db.collection("studentsdetails").update(myquery, newvalues, function(err, res) {
    if (err) throw err;
    console.log(res.result.nModified + " record updated");
    db.close();
});
});

QUERY

You can find records from a table by using find() method.

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
var query = { address: /^S/ };
db.collection("studentdetails").find(query).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
});
});

23/05/2017

                                           MONGODB NODEJS

SORT

Use the sort() method to sort the result in ascending or descending order.

Use the value -1 in the sort object to sort descending.
{ name: 1 } // ascending
        { name: -1 } // descending

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
var mysort ={name:1}; db.collection("studentsdetails").find().sort(mysort).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
});
});

REMOVE

Use the remove() method to delete records, or documents.

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
var myquery = { address: 'Colombo' }; db.collection("studentsdetails").remove(myquery, function(err, obj) {
    if (err) throw err;
    console.log(obj.result.n + " document(s) deleted");
    db.close();
});
});

Wednesday, June 7, 2017

22/05/2017

                                    MongoDB select from

Select one

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/music";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
var query = { musicDirector: 'AR Rahman' };
db.collection("songdetails").find(query).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
});
});

sort

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
var mysort = { name: -1 }; db.collection("students").find().sort(mysort).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
});
});

Remove

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
var myquery = { address: 'Mountain 21' }; db.collection("students").remove(myquery, function(err, obj) {
    if (err) throw err;
    console.log(obj.result.n + " document(s) deleted");
    db.close();
});
});

Tuesday, June 6, 2017

19/05/2017

Nodejs Mongo DB

Create a database

Create a database called "uki":
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
console.log("Database created!");
db.close();
});

Create a table

Create a table called "students":

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/uki";

MongoClient.connect(url, function(err, db) {
if (err) throw err;
db.createCollection("students", function(err, res) {
    if (err) throw err;
    console.log("Table created!");
    db.close();
});
});

Insert in to table

18/05/2017

Nodejs File System

File System module:

Read files
Create files
Update files
Delete files
Rename files

Read a file

The fs.readFile() method is used to read files.

Create files

fs.appendFile()
fs.open()
fs.writeFile()

Update files

fs.appendFile()

fs.writeFile()

Delete files

fs.unlink()

Rename files

fs.rename()

17/05/2017

NODEJS

What is Node.js?

Node.js is an open source server framework
Node.js is free
Node.js runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
Node.js uses JavaScript on the server

NODEJS MODULE

Consider modules to be the same as JavaScript libraries.

A set of functions you want to include in your application.

To include a module, use the require() function with the name of the module:
   var http = require('http');

Create a own module
you can create your own modules, and easily include them in your applications.
       exports.myDateTime = function () {
    return Date();
};

16/05/2017

MONGODB

MongoDB is an open-source document database and leading NoSQL database

MongoDB is a cross-platform, document oriented database that provides, high performance, high availability, and easy scalability. MongoDB works on concept of collection and document.

Advantages of MongoDB over RDBMS

Schema less − MongoDB is a document database in which one collection holds different documents. Number of fields, content and size of the document can differ from one document to another.
Structure of a single object is clear.
No complex joins.
Deep query-ability. MongoDB supports dynamic queries on documents using a document-based query language that's nearly as powerful as SQL.
Tuning.
Ease of scale-out − MongoDB is easy to scale.
Conversion/mapping of application objects to database objects not needed.
Uses internal memory for storing the (windowed) working set, enabling faster access of data.

Why Use MongoDB?
Document Oriented Storage − Data is stored in the form of JSON style documents.
Index on any attribute
Replication and high availability
Auto-sharding
Rich queries
Fast in-place updates
Professional support by MongoDB

Where to Use MongoDB?

Big Data

Content Management and Delivery

Mobile and Social Infrastructure

15/05/2017

DATABASE

   A database is a collection of information that is organized so that it can be easily accessed, managed and updated.

1.create a database
create database databasename;

2. drop a database
drop database databasename;

3.create table

create table table_name (
    column1 datatype,
    column2 datatype,
    column3 datatype,

);

4.drop table
drop table table_name;

5.alter table
The alter table statement is used to add, delete, or modify columns in an existing table.
     1.alter table table_name
        add column_name datatype;

   2.alter table table_name
        drop column column_name;

janusha