Dreamweaver CS4
Live view
Cs4 provides you with a new live rendering mode. In this mode the changes you make in the coding are immediately reflected on the rendered display. This mode uses the open source rendering engine web kit. In this feature thus the brain of interactive coding works with the beauty of real world rendering to provide you the best and effective websites.
Photoshop smart objects
With this facility you can simply drag a Photoshop (PSD) image into Dreamweaver and it creates a smart object. A smart object is linked to its source file. The source code of the image and the instance on the web page are in synchronization. There is an indicator on the smart object. When any changes are made to source image, Dreamweaver takes a note of that and to update it you can click update from original icon in property panel thus updating your image on the web browser without opening Photoshop.
Related files and code navigator
This new feature helps you o manage your related files more efficiently. This feature displays all document associated with your current page. Changes made in the code in related files are directly reflected in design view.
Code hinting for Ajax and JavaScript framework
Dreamweaver cs4 provides advance code hinting functionality. Popular JavaScript framework such as jQuery, prototype and spry can be easily added due to the extended coding facility. The facility of Built in error detection helps you to write error free code for your website.
New user interface
The new user interface of creative suite 4 helps you to manage your work smarter and faster. You can stack or minimize your doc panels you can work in split code view which displays your code in two different sections. Workspace pull down list is provided in this suite to move quickly from one to the other workspace. There are many predesigned layouts available for your workspace and you can also customize your workspace.
Subversion integration
When you work on a project in collaborative environment there is a need to handle version control. For doing so there is Subversion software to handle version control. The CS4 provides subversion for file versioning, rollback and more. Once you are finished defining subversion as your version control system, you can update your site to get the latest version of its pages.
HTML data set support
The Dreamweaver CS4 provides easy accessibility and usage in the new features of the data set. With this advance feature you are able to create your data in a standard HTML table, a series of div tags, or even an unordered list. Then this data can be integrated into a dynamic table on the web page with sort able columns. There is a spry data set which works with XML files.
MD5
There should be a way to guarantee that the files, message, passwords received at the receivers end is complete and modified. The MD5 or the message digest 5 algorithm is one of the simplest and the quickest way to add security to message and files that you send and transfer. MD5 was developed by a professor of the MIT in 1991. His name was Ronald L. Rivest. The earlier hash function generator MD4 had some flaws in its design and was not providing enough security, hence MD5 was designed. This algorithm calculates a hash value i.e. the digest of any message, text, password or files. This hash value generated works as a fingerprint for the text or the message on which you applied the MD5 algorithm. The length of the hash value generated is 128 bit. It is written as a character string of 32 hexadecimal digits. The MD5 algorithm is designed in such a way that it is not possible to produce two identical messages, text or password whose hash value will be the same. The Md5 algorithm thus is also used for comparing large amount of data based on the hash value generated.
Many people also think that MD5 is some kind of encryption software. MD5 is not encryption software but a hash value generator algorithm. Md5 is also used to verify the integrity of a file or a string.
Algorithm
The MD5 takes variable length message or text as data input and provides with a fixed length output of 32 hexadecimal digits. The input message is broken into fixed length block of 512 bits. If in last block bits are remaining then padding is doe so that the complete length of the message or text becomes divisible by 512. The processing of these blocks is then done in four stages. In every stage some kind of function is applied on each block of the message. These functions are non linear functions. After non linear functions, modular addition is done on these blocks. After this step of modular addition rotation of bits is done. Finally the hash key corresponding to these bits are generated.
Example
Consider that a hash value has to be generated for a password. When the password is entered by the user the length of the password will be checked. Depending upon the length of the password necessary padding will be done so as to make the length of the password divisible by 512. The padded message block will pass from four rounds of processing. This processing will include non linear functions, arithmetic and logical operations, shifting and rotating of bits etc. At last the hash value will be generated based on these processing.
How does it work
The sender first generates the hash value of the message, password or the data which it needs to send. Then he sends the message or text to the receiver. The hash value generated is then conveyed to the receiver in separate message. On receiving the text from the sender, the receiver applies the MD5 algorithm again on the text received. If the hash value generate is same as the hash value send by the sender then the message is correct and not modified.
PHP
PHP stands for hypertext preprocessor. PHP scripts are executed on the server. PHP is an open source technology. It was created by Rasmus Lerdorf who worked for Linuxcare incorporation as a senior open source researcher. PHP supports many databases such as mySQL, Informix, oracle, Sybase, solid, postgreSQL , generic ODBC etc. PHP is platform independent software and works effectively for all major UNIX, LINUX and windows operating system. PHP was written specially for interacting with the web. PHP code is embedded directly into XHTML documents. The PHP code is inserted between opening and closing delimiters. For example php phpinfo() . Here Is the opening delimiter and is the closing delimiter.
Why PHP is used for this website
PHP is a scripting language and with the help of scripts you can add many interactive features to your website. These interactive features like feedback forms, message boards , guest books, scrapbooks, counters and even more advance features like content management and advertising management becomes very easy with the use of PHP. PHP programs can be written in any text editor (notepad in windows). PHP is free open source software and it can be easily downloaded and used.
String processing and regular expressions
PHP process text data easily and effectively. It enables straight forward searching, substitution, extraction and concatenation of strings. Text manipulation is usually done with regular expressions i.e. a series of characters that serve as pattern matching templates in string, text files and databases. Relational operations (,,, ,,) can also be used to compare strings. For more powerful string comparisons there are ereg and preg_match functions. Function ereg uses portable operating system interface (POSIX).
PHP data types and variables
PHP variables are preceded by special symbol. A variable is created automatically when it is first encountered by PHP interpreter. PHP provides capability to store data in arrays. Arrays are divided into elements that behave as individual variables. Numbers are stored in platform dependent range. The range is of 32 bit signed integers. Floating point numbers are also stored in platform specific range.
Viewing clientserver environment variables
Knowledge of client execution environment is useful for system administrator who wants to provide client specific information. Environment variables contain information about a script environment such as the client web browser, the HTTP hosts and the HTTP connection information. PHP stores the environment variables and their values in the global array.
PHP cookies
Cookies maintain state information for a particular client who uses a web browser. Cookies are often used to record user preferences or other user related information that will be retrieved during clients visit to a website. On server side cookies can be used to track info about client activity. The data stored in the cookies is send back to the web server from which it originated whenever the user requests a web page from that particular server.
PHP sessions
There exits a relationship between session and cookies. They somewhat serve the same purpose up to some extent. Sessions are means to track and store data for a user while he travels from page to page on your website. Sessions are started with the help of session_start () function. A random session id is generated by this function. Information for a session is stored in session variables.
Apart from these features many other features like form and data control, file system related operations, error handling, logic flow etc are provided by the PHP. All these valuable features are the reasons why PHP is becoming so popular among website developers.
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