Difference between SGML, and XML

XML is a markup language. A markup language used tags to indicate how a file should look when displayed on a web page. Some examples of markup language are standard generalized markup language (SGML)and Hypertext markup language (HTML)

SGML was related in1980. SGML allows documents to describe their own grammar by specifying the tag set used in the documents and the structural relationship that these represent. this makes it possible to define your own formats for documents, handle large and complex and difficult for developers to master.

What is XML ?

Extensible markup language (XML) is a text-based markup language that enables you to store data in a structured format by using meaningful tags. The term “extensible” implies that you can extend your ability to describe a documents by defining meaningful tags for your application.

XML is a cross- platform, hardware and software independent markup language. XML allows computers to store Data in a format that can be interested by any other computer system and there for, XML can be used to transfer structured data between heterogeneous system, XML is used as a common data interchange format in a number of application s. in this case of the B2B e-commerce model is used for exchanging data between various trading partners. Thus, XML can be used to address the problems faced by EDI.

Adding a Hyperlink column to Data grid control

This is a very important concept in Data grid controls. To display links to other pages from the Data grid a Hyper link column can be used. This type of column is useful in two situations.

First, a Hyper link column can be used. For example create a master-detail form a set of master records can be displayed in a Data grid and a Hyper link column can be used in the Data grid to link to a separate page that contains detailed information.

Secondly it can be used for interlinking paged and websites with each other, can important need of web programmers.

Adding a bound Column to a Data Grid

The default column used in a Data grid is a bound column. If only limited columns are to be displays and controlled from a Data source, declaration of one more Bound Columns controls is done explicitly. The following example demonstrates it :-

The above example, displays only the first Name and Last Name columns from the Employees table.

Note that the Data grid controls auto generate columns property is set the not value false so that, all the columns from the Employees table are displayed , and the First Name columns are displayed twice as shown below :-

Therefore it is important to take care of auto generate columns property of data grid control.

Further in the above example the Bound columns are declared inside the Data grid controls tag. This tag contains a bound column for the Titles column and a bound column for price column. The Data field property indicates the field from the source to display in the bound column.

Data Grid Events

The Data Grid control supports several events.

One of them, the Item Created event,gives you a way to customize the item-creation process. The item Data Bound event also gives you the ability to customize the Data Grid item, but after the data is available for inspection. For example, if you were using the Data Grid control to display to do list, you could display overdue items in red text, completed items in black text and other tasks in green text.

The remaining event are raised in response to button or link button clicked in grid items They are designed to implement common data manipulation tasks. Four events of this type are supported:

Edit command

Delete Command

Update Command

Cancel command

When the user clicks one of the button (labeled by default Edit, Delete, Update, or Cancel ,respectively ),the corresponding event is raised.

The data Grid control also supports the item Command event that is raised when a user clicks a button that is not one of the predefined buttons above. This even can be used for custom functions by setting a button’s command Name property to a value needed, and then testing for it in the item command event handler.

(For example. You could use this approach when selecting an item , as documented in allowing Users to select item in a data list web server control.) by default, a data grid simply displays all columns control’s Auto generate Columns property, columns can be created individually to have more control over the formatting.