Java Script Frameworks ..

JavaScript Frameworks:

JavaScript Client side framework - Angular JS

JavaScript Server side framework - Sails JS

JavaScript Client side Unit Testing framework - Jasmine

JavaScript Client side & Server side Unit Testing framework - Mocha

JavaScript Assertion libraries - Chai JS

JavaScript test spies, stubs, mocks - Sinon JS

JavaScript E2E Test Automation(for AngularJS) - Protractor JS

Client side Test Automation:

1. Angular JS
2. Chai JS
3. Sinon JS
4. protractor JS

Server side Test Automation:

1. Mocha JS
2. Chai JS
3. Sinon JS
4. protractor JS

Design rules to check while selecting framework:

1. Multi-Browser support(Chrome, Firefox, IE)
2. Popularity in the tribe
3. Good documentation 

Miscellaneous:

Cucumber framework has more support for .net, java ..

Grunt is a JavaScript Build tool …

Keywords: stub, restore, spies, assert, expect, verify, webdriver, selenium, cucumber, grunt

Technology Update

1. AngularJS website - http://angularjs.org/

2. AngularJS Batarang – http://blog.angularjs.org/2012/07/introducing-angularjs-batarang.html

Chrome extension to debug AngularJS application. Extends the Developer Tools, adding tools for debugging and profiling AngularJS applications.

3. Bootstrap .css file => http://twitter.github.com/bootstrap/

Twitter Bootstrap is a free collection of tools for creating websites and web applications. It contains HTML and CSS-based design templates for typography, forms, buttons, charts, navigation and other interface components, as well as optional JavaScript extensions

4. AMD (requirejs) - http://requirejs.org/docs/whyamd.html

The Asynchronous Module Definition (**AMD**) API specifies a mechanism for defining modules such that the module and its dependencies can be asynchronously loaded. This is particularly well suited for the browser environment where synchronous loading of modules incurs performance, usability, debugging, and cross-domain access problems.

5. Playground for WebDevelopers – http://jsfiddle.net/

jsFiddle is a playground for web developers, a tool which may be used in many ways. You can use it as an online editor for snippets build from HTML, CSS and JavaScript.

7. WebStorm Application can be used to perform ‘Remote Debugging’ web applications.

8. Chef is a configuration management tool written in Ruby and Erlang. It uses a pure-Ruby, domain-specific language (DSL) for writing system configuration "recipes" or "cookbooks". Chef was written by Opscode and is released as open sourceunder the Apache License 2.0. Chef is a DevOps tool used for configuring cloud services or to streamline the task of configuring a company's internal servers. Chef automatically sets up and tweaks the operating systems and programs that run in massive data centers.

9. Erlang is a general-purpose concurrent, garbage-collected programming language and runtime system. The sequential subset of Erlang is a functional language, with strict evaluation, single assignment, and dynamic typing. It was designed by Ericsson to support distributed, fault-tolerant, soft-real-time, non-stop applications. It supports hot swapping, so that code can be changed without stopping a system. Facebook uses Erlang to power the backend of its chat service, handling more than 100 million active users.It can be observed in some of its HTTP response headers.

10. Splunk - Splunk captures, indexes and correlates real-time data in a searchable repository from which it can generate graphs, reports, alerts, dashboards and visualizations. It aims tomake machine data accessible across an organization and identifies data patterns,provides metrics, diagnoses problems and provides intelligence for business operation.

11. Nagios - Nagios is an open source computer system monitor, network monitoring and infrastructure monitoring software application. Nagios offers monitoring and alerting for servers, switches, applications, and services. It alerts users when things go wrong and alerts them again when the problem has been resolved.

12. Apache POI - Pure Java libraries for reading and writing files in Microsoft Office formats, such as Word, PowerPoint and Excel.

The Apache POI project(http://en.wikipedia.org/wiki/Apache_POI) contains sub components like - 

• HSSF (Horrible SpreadSheet Format) – reads and writes Microsoft Excel (XLS) format files. It can read files written by Excel 97 onwards; this file format is known as the BIFF 8 format. As the Excel file format is complex and contains a number of tricky characteristics, some of the more advanced features cannot be read.
• XSSF (XML SpreadSheet Format) – reads and writes Office Open XML (XLSX) format files. Similar feature set to HSSF, but for Office Open XML files.

AngularJS - OpenSource JavaScript Framework

AngularJS is an open-source JavaScript framework. Its goal is to augment browser-based applications with Model–View–Controller (MVC) capability, reduce the amount of JavaScript needed to make web applications functional. These type of apps are also known as Single-Page Applications.

The Philosophy of Angular:

Angular is built around the belief that declarative programming is better than imperative programming when it comes to building UIs and wiring software components together, while imperative code is excellent for expressing business logic.

Design goals:

1. Decouple DOM manipulation from app logic. This improves the testability of the code.
2. Regard app testing as equal in importance to app writing. Testing difficulty is dramatically affected by the way the code is structured.
3. Decouple the client side of an app from the server side. This allows development work to progress in parallel, and allows for reuse of both sides.
4. Guide developers through the entire journey of building an app: from designing the UI, through writing the business logic, to testing.
5. Make common tasks trivial and difficult tasks possible.

Notable Features:

1. Two Way Data-Binding
2. Templates
3. MVC
4. Dependency Injection
5. Derivatives

Notable Angular Directives:

1. ng-repeat: Instantiate an element once per item from a collection.
2. ng-show & ng-hide: Conditionally show or hide an element, depending on the value of a boolean expression.
3. ng-switch: Conditionally instantiate one template from a set of choices, depending on the value a selection expression.

ref:

AngularJS Home Page - http://angularjs.org/

AngularUI Home Page - http://angular-ui.github.com/

AngularJS Wiki - http://en.wikipedia.org/wiki/AngularJS


Developing an AngularJS Application with HTML5 Socket.IO - http://www.html5rocks.com/en/tutorials/frameworks/angular-websockets/

REST vs SOAP

SOAP (Simple Object Access Protocol) and REST (Representational State Transfer) provide mechanisms for requesting information from endpoints (SOAP) or from resources (REST). Perhaps the best way to think of these technologies is as a method of making a remote procedure calls against a well-defined API. SOAP has a more formal definition mechanism called WSDL (Web Services Definition Language) and is a bit more complex to implement. REST uses the standard HTTP request and response mechanism, simplifying implementation and providing for a looser coupling of the client and server. Note that REST also supports the transfer of non-XML messages such as JSON (JavaScript Object Notation

Which is better, REST or SOAP?

This is one of the most common questions I get about REST, and it is probably the least fair. Both REST and SOAP are often termed "Web services," and one is often used in place of the other, but they are totally different approaches. REST is an architectural style for building client-server applications. SOAP is a protocol specification for exchanging data between two endpoints.

Comparing REST with the remote procedure call (RPC) style of building client-server applications would be more accurate. RPC is a style (rather than a protocol, which is what SOAP is) of building client-server applications in which a proxy (generally generated from metadata) is used in the client's address space to communicate with the server and the proxy's interface mimics the server's interface. Although SOAP doesn't require the RPC style, most modern SOAP toolkits are geared toward (at least they default to) using RPC.

In contrast to RPC, REST lacks the metadata-generated proxy (see the next question for more information), which means that the client is less coupled to the service. Also, because REST relies on the semantics of HTTP, requests for data (GET requests) can be cached. RPC systems generally have no such infrastructure (and even when performing RPC using SOAP over HTTP, SOAP responses can't be cached because SOAP uses the HTTP POST verb, which is considered unsafe). SOAP intentionally eschews HTTP, specifically to allow SOAP to work over other protocols, so it's actually a little disingenuous to call SOAP-based services Web services.

My perspective is that both REST and SOAP can be used to implement similar functionality, but in general SOAP should be used when a particular feature of SOAP is needed, and the advantages of REST make it generally the best option otherwise.

ref:

Rest vs Soap -

http://blogs.msdn.com/b/swiss_dpe_team/archive/2008/11/28/rest-vs-soap.aspx

http://msdn.microsoft.com/en-us/magazine/dd942839.aspx

Soap vs Rest discussions - http://blogs.msdn.com/b/zainnab/archive/2007/12/16/rest-vs-soap-decision-decisions-decisions.aspx

Introduction to Restful Webservices - http://msdn.microsoft.com/en-us/magazine/dd315413.aspx

Web Services, Part 1: SOAP vs. REST - http://www.ajaxonomy.com/2008/xml/web-services-part-1-soap-vs-rest

Stefan Tilkov: REST vs SOAP - http://www.innoq.com/blog/st/2006/06/30/rest_vs_soap_oh_no_not_again.html

Roots of REST vs SOAP - http://www.prescod.net/rest/rest_vs_soap_overview/

REST vs SOAP from StackOverflow -http://stackoverflow.com/questions/209905/rest-and-soap

Giving SOAP a REST -http://www.devx.com/DevX/Article/8155

Http Message Length

The transfer-length of a message is the length of the message-body as it appears in the message; that is, after any transfer-codings have been applied. When a message-body is included with a message, the transfer-length of that body is determined by one of the following (in order of precedence):

1.Any response message which "MUST NOT" include a message-body (such as the 1xx, 204, and 304 responses and any response to a HEAD request) is always terminated by the first empty line after the header fields, regardless of the entity-header fields present in the message.

2.If a Transfer-Encoding header field (section 14.41) is present and has any value other than "identity", then the transfer-length is defined by use of the "chunked" transfer-coding (section 3.6), unless the message is terminated by closing the connection.

3.If a Content-Length header field (section 14.13) is present, its decimal value in OCTETs represents both the entity-length and the transfer-length. The Content-Length header field MUST NOT be sent if these two lengths are different (i.e., if a Transfer-Encoding

     header field is present). If a message is received with both a      Transfer-Encoding header field and a Content-Length header field,      the latter MUST be ignored. 

4.If the message uses the media type "multipart/byteranges", and the transfer-length is not otherwise specified, then this self- delimiting media type defines the transfer-length. This media type MUST NOT be used unless the sender knows that the recipient can parse it; the presence in a request of a Range header with multiple byte- range specifiers from a 1.1 client implies that the client can parse multipart/byteranges responses.

       A range header might be forwarded by a 1.0 proxy that does not        understand multipart/byteranges; in this case the server MUST        delimit the message using methods defined in items 1,3 or 5 of        this section. 

5.By the server closing the connection. (Closing the connection cannot be used to indicate the end of a request body, since that would leave no possibility for the server to send back a response.)

For compatibility with HTTP/1.0 applications, HTTP/1.1 requests containing a message-body MUST include a valid Content-Length header field unless the server is known to be HTTP/1.1 compliant. If a request contains a message-body and a Content-Length is not given, the server SHOULD respond with 400 (bad request) if it cannot determine the length of the message, or with 411 (length required) if it wishes to insist on receiving a valid Content-Length.

All HTTP/1.1 applications that receive entities MUST accept the "chunked" transfer-coding (section 3.6), thus allowing this mechanism to be used for messages when the message length cannot be determined in advance.

Messages MUST NOT include both a Content-Length header field and a non-identity transfer-coding. If the message does include a non- identity transfer-coding, the Content-Length MUST be ignored.

When a Content-Length is given in a message where a message-body is allowed, its field value MUST exactly match the number of OCTETs in the message-body. HTTP/1.1 user agents MUST notify the user when an invalid length is received and detected.

Chunked transfer encoding

From Wikipedia, the free encyclopedia

Chunked transfer encoding is a data transfer mechanism in the Hypertext Transfer Protocol (HTTP) that allows HTTP data to be reliably delivered between a web server and a clientapplication, usually a web browser, without knowing in advance of transmission the size of the entire message body. This is achieved by splitting the data payload of the message in small parts (chunks) and transmitting with each chunk its size. The data transfer is terminated by a final chunk of length zero. This makes it possible to transmit dynamically generated content in web pages. The chunked method is only available in version 1.1 of the HTTP protocol (HTTP/1.1).

Without chunked transfer encoding, the size of data delivered in HTTP responses must be indicated by the Content-Length header field to allow clients to determine the end of transmission.

Format

If a Transfer-Encoding field with a value of chunked is specified in an HTTP message (either a request sent by a client or the response from the server), the body of the message consists of an unspecified number of chunks, a terminating last-chunk, an optional trailer of entity-header fields, and a final CRLF sequence.

Each chunk starts with the number of octets of the data it embeds expressed in hexadecimal followed by optional parameters (chunk extension) and a terminating CRLF (carriage returnand line feed) sequence, followed by the chunk data. The chunk is terminated by CRLF. If chunk extensions are provided, the chunk size is terminated by a semicolon followed with the extension name and an optional equal sign and value.

The last chunk is a zero-length chunk, with the chunk size coded as 0, but without any chunk data section.

The final chunk may be followed by an optional trailer of additional entity-header fields that are normally delivered in the HTTP header to allow the delivery of data that can only be computed after all chunk data has been generated. The sender may indicate in a Trailer header field which additional fields it will send in the trailer after the chunks.

[edit]Example

[edit]Encoded response

HTTP/1.1 200 OK Content-Type: text/plain Transfer-Encoding: chunked  25 This is the data in the first chunk  1C and this is the second one  3 con 8 sequence 0  

[edit]Anatomy of encoded response

The first two chunks contain explicit \r\n characters in the chunk data.

"This is the data in the first chunk\r\n"      (37 chars => hex: 0x25) "and this is the second one\r\n"               (28 chars => hex: 0x1C) "con"                                          (3  chars => hex: 0x03) "sequence"                                     (8  chars => hex: 0x08) 

The response ends with a zero-length last chunk: "0\r\n" and the final "\r\n".

[edit]Decoded data

This is the data in the first chunk and this is the second one consequence

Http Message Overview

Http Status Codes

Status Codes

HTTP status codes are returned by web servers to describe if and how a request was processed. The codes are grouped by the first digit:

1xx - Informational

Any code starting with '1' is an intermediate response and indicates that the server has received the request but has not finished processing it. For example, IIS initially replies with 100 Continue when it receives a POST request and then with 200 OK once it has been processed

2xx - Successful

These codes are used when a request has been successfully processed. For example, the value 200 is used when the requested resource is being returned to the HTTP client in the body of the response message.

3xx - Redirection

Codes starting with a '3' indicate that the request was processed, but the browser should get the resource from another location. Some examples are:

302	The requested resource has been temporarily moved and the browser should issue a request to the URL supplied in the Location response header.
304	The requested resource has not been modified and the browser should read from its local cache instead. The Content-Length header will be zero or absent because content is never returned with a 304 response

4xx - Client Error

The server returns these codes when they is a problem with the client's request. Here are some examples:

401	Anonymous clients are not authorized to view the requested content and must provide authentication information in the WWW-Authenticate request header.
404	The requested resource does not exist on the server

5xx - Server Error

A status code starting with the digit 5 indicates that an error occurred on the server while processing the request. For example:

500	An internal error occurred on the server. This may be because of an application error or configuration problem
503	The service is currently unavailable, perhaps because of essential maintenance or overloading

Http Authentication

Here is a typical transaction between an HTTP client and an HTTP server running on the local machine (localhost). It comprises the following steps.

1. The client asks for a page that requires authentication but does not provide a user name and password. Typically this is because the user simply entered the address or followed a link to the page.

2. The server responds with the 401 response code and provides the authentication realm.

3. At this point, the client will present the authentication realm (typically a description of the computer or system being accessed) to the user and prompt for a user name and password. The user may decide to cancel at this point.

4. Once a user name and password have been supplied, the client adds an authentication header (with value base64encode(username+":"+password)) to the original request and re-sends it.

5. In this example, the server accepts the authentication and the page is returned. If the user name is invalid or the password incorrect, the server might return the 401 response code and the client would prompt the user again.

Note: A client may pre-emptively send the authentication header in its first request, with no user interaction required.

Http Encoding

When an HTTP client is reading a response message from a server it needs to know when it has reached the end of the message. This is particularly important with persistent (keep alive) connections, because a connection can only be re-used by another HTTP transaction after the response message has been fully received. The following sections describe the four ways in which an HTTP server can indicate the end of the response message:

Connection Closed by Server

The connection can be closed at the end of the response message by the server, but this prevents connections being re-used.

Content-Length Header

The length of the content after the response headers can be specified in bytes with the Content-Length header

Implied Content Length

Some types of responses, such as 304, are defined to never have content and therefore the client can assume that the response message is terminated by the double CRLF after the headers.

Chunked Encoding

The content can be broken up into a number of chunks; each of which is prefixed by its size in bytes. A zero size chunk indicates the end of the response message. If a server is using chunked encoding it must set theTransfer-Encoding header to "chunked".

Chunked encoding is useful when a large amount of data is being returned to the client and the total size of the response may not be known until the request has been fully processed. An example of this is generating an HTML table of results from a database query. If you wantedto use the Content-Length header you would have to buffer the whole result set before calculating the total content size. However, with chunked encoding you could just write the data one row at a time and write a zero sized chunk when the end of the query was reached.

ref:

Http Wiki - http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol

Http header fields - http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html

How to find ed of Http response - http://www.httpwatch.com/httpgallery/chunked/

HttpMessage structure - http://web-sniffer.net/

Http Message - http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html

Http Authentication – http://en.wikipedia.org/wiki/Basic_access_authentication

HTTP Status Codes and Errors -http://www.httpwatch.com/httpgallery/errors/

http 1.1 RFC - http://www.w3.org/Protocols/rfc2616/rfc2616.html

http over TLS RFC - http://tools.ietf.org/html/rfc2818

ssl 3.0 RFC - http://tools.ietf.org/html/draft-ietf-tls-ssl-version3-00