Data flow diagram

A data flow diagram (DFD) is a graphical representation of the "flow" of data through an information system, modelling its process aspects.

Data flow diagram - notation.

DFD is top-down designing approach in which

(a)A high-level function is decomposed into a set of easy understandable function.

(b)Each function performed by system is analyzed and decomposed into more detailed description.

A DFD models a system by using external entities from which data flows to a process which transform the data and creates output data flow which go to other processes or external entities or data stores . From data stores, stored data may also flow to process as inputs.

Dfd with example

Here External entity 1 gives input data to process1 after this processed data 1 is stored in data store , now stored data is given to process 2 and finally processed data 2 is consumed by External entity 2.

Physical DFD to issue a book from library:-

Logical DFD to issue a book from library(above)

DFD for university routine management project

zero level DFD for university routine management project.

generation on available resources like programmes, courses, subjects, teachers, lecture room/lab preferences. Assignments/lecture notes upload , Daily class attendance, student feedback, exams marks updation and students/faculty profile management would be the integral part of this system.

User of the System:

A. End-user/students

B. Data Manager

C. Subject Teacher

D. Admin/Dean/Director

first and second level DFD of university management

Description for zero level DFD

• As stated in the question there are 4 users in the project.
  
• Here detailed informations regarding each student and teacher are given and in response every student has got SIN(student identification num) or Roll No. and for teacher it is TIN(teacher identification num).
  
• Database Manager will perform all the data entry job.
  
• After giving routine generating command a routne will be generated.
  
• Admin can veiw the every user , his peformance and get the result by giving the query. first level DFD of university management:

Description of 1st level:

every student , every teacher , evey class room and every subject should be registerd

Here student_info datastore contain information regarding student.

Here teacher_info datastore contain information regarding teacher.

Here class_info datastore contain information regarding class.

Here subject_info datastore contain information regarding

second level DFD of university management:

Typical CakePHP Request

I am covered the basic ingredients in CakePHP, so let’s look at how objects work together to complete a basic request. Continuing with our original request example, let’s imagine that our friend Ricardo just clicked on the “Buy A Custom Cake Now!” link on a CakePHP application’s landing page.

Figure: 2. Typical Cake Request.

Black = required element, Gray = optional element, Blue = callback

1. Ricardo clicks the link pointing to http://www.example.com/cakes/buy, and his browser makes a request to your web server.
2. The Router parses the URL in order to extract the parameters for this request: the controller, action, and any other arguments that will affect the business logic during this request.
3. Using routes, a request URL is mapped to a controller action (a method in a specific controller class). In this case, it’s the buy() method of the CakesController. The controller’s beforeFilter() callback is called before any controller action logic is executed.
4. The controller may use models to gain access to the application’s data. In this example, the controller uses a model to fetch Ricardo’s last purchases from the database. Any applicable model callbacks, behaviors, and DataSources may apply during this operation. While model usage is not required, all CakePHP controllers initially require at least one model.
5. After the model has retrieved the data, it is returned to the controller. Model callbacks may apply.
6. The controller may use components to further refine the data or perform other operations (session manipulation, authentication, or sending emails, for example).
7. Once the controller has used models and components to prepare the data sufficiently, that data is handed to the view using the controller’s set() method. Controller callbacks may be applied before the data is sent. The view logic is performed, which may include the use of elements and/or helpers. By default, the view is rendered inside of a layout.
8. Additional controller callbacks (like afterFilter) may be applied. The complete, rendered view code is sent to Ricardo’s browser.

MVC Architecture

1. The Model represents the application data
2. The View renders a presentation of model data
3. The Controller handles and routes requests made by the client

Figure: 1: A Basic MVC Request