My Experience with document.getElementById()

Hello friends,

I would like to share one interesting experience with you.

Currently, I was working with Asp.Net tree view. The data in tree view is very large, so we implemented search functionality in tree view. User can add text of a node to be searched. If more than one node found, each node will be checked in tree view. As I have mentioned the data in a tree is very large, so we have kept this tree inside a panel so that user can scroll up or down to view entire tree view.

Then one more client requirement came. When a node found during a search, panel should be scrolled down to location of that particular node in tree view. For that we have used document.getElementById('TreeView1_SelectedNode') to get selected node. Then using its location. we have scrolled panel.

Here comes interesting part. What if I have more than one selected node. I was under the impression that it should return first selected node and ignore the rest. However, I was surprised that it returns me last selected node and panel scrolled down to last selected node.

RowDetailsTemplate in Silverlight DataGrid

This is my first blog on silverlight. Silver datagrid does not support hierarchical data directly. I had a task to create hierarchical datagrid in Silverlight. I have explored many options and during which I came to know about two good features. One is RowDetailsTemplate in Silverlight Datagrid, and another is RowGrouping feature. This blog is about RowDetailsTemplate.

Generally, RowDetailsTemplate is used to display additional information of a row. It has many advantages. First it does not affect a dimension of rows and cells. Its visibility can be managed on row wise.

To create RowDetailsTemplate for row in datagrid we have to set RowDetailsTemplate to as particular template. It can hold any control. Following is an example of RowDetailsTemplate.


<data:datagrid name="datagrid1" row="0" column="0" rowdetailsvisibilitymode="Collapsed">
     <data:datagrid.rowdetailstemplate>
       <datatemplate>
         <data:datagrid name="datagrid2" headersvisibility="None">
         </data:datagrid>
       </datatemplate>
     </data:datagrid.rowdetailstemplate>
</data:datagrid>






As we can see from above code that we can put any control inside RowDetailsTemplate. Here we have kept another grid inside RowDetailsTemplate. Control inside row details shares same data context as of data grid so we can bind controls inside row details.

With RowDetailsVisibilityMode, we can set visibility of row details it has three values.

1) Collpased: Row details are not visible.
2) Visible: Row details are visible.
3) VisibleWhenSelected: When a row selected its row details will be visible.

Default value is VisibleWhenSelected.

RowDetailsVisibilityChanged event is available when row detail visibility changed. With RowDetailsVisibilityMode set to visible when selected, when a row gets selected RowDetailsVisibilityChanged event gets fired. This event also fires for the first row when another row is selected.

Furthermore, we can control detail visibility of an individual rows with DetailsVisibility property of Row.

In short RowDetailsTemplate is a powerful feature of silverlight data grid. Developer can enhance interactivity and functionality of data grid with this feature.

I have used this feature to create hierarchical data grid. If you have any questions or comments, please let me know.

Microsoft Word Document Automation using XSL and XML

Here is My first technical blog!!!

First of all, what is document automation?

In a simple term generating word document without the use of Microsoft Office.

Why its required?

Although Microsoft Office is easy to use, and it is very user friendly, many find it difficult to use(I am one of them). At least when the document involves complex formatting.

Consider the example of Invoice. It contains customer information, product information, date, company information, etc. Each Invoice has some common things like same design, company information. Only date, customer name, product information will be different. Now consider a business in which thousands of invoices will be generated during the whole day. Each time if a user has to create new word document, enter data then it will be a time consuming task for user.

Here document automation comes in to picture. What if a user has a software in which user has to enter only data like customer name, product information and document will be generated for the user. It's very easy for user. There are many examples in a real world where document automation is very useful. Basically, we can use document automation where format of document does not change only content to document changes.

Background

I have worked on document automation projects. Here a requirement was to automate course plan and MOM(Minutes of Meeting) document. Course plan document contains all the course information like the title of course, pre requisites for the course, session details, objective of the session, points to be covered in session. MOM document contains meeting information like who are the invites, time of meeting, agenda of meeting. These documents contain complex formatting.

A first step was to create application so that user can enter data. I have created Asp.Net application, where a user can enter data through GUI. Data will be stored in Sql server so that anytime user can re generate a document. Main part of the projects was to create word document from data that user has entered and stored in a sql server. I have decided to use XML and XSL.

Introduction to XML

XML stands for Extensible Markup Language. It is a markup language same is HTML. XML is designed for data communication. There are no predefined tags like HTML in XML. User can define own tags. It's a self descriptive. What does it mean by self descriptive? Author of XML document can specify own tags.

Consider following example of XML document

<companyinfomation>
<companyname>ABC Pvt. Ltd.</companyname>
<companyaddress>XYZ Road,Andheri,Mumbai</companyaddress>
<numberofemployees>20</numberofemployees>
</companyinfomation>

From above XML anyone can get that it is the company information of ABC Pvt. Ltd. which is in mumbai and it has 20 employees.

XML simplifies data sharing. Nowadays, a days many RDBMS systems are available. Data sharing is difficult because each RDBMS has its own format to store data like Sql server uses .mdf file. Using XML data storing will be independent. It also makes data transportation easy. Now a days XML are used at many places like RSS(my next topic),WSDL,Open office XML, etc.

Introduction to XSL

XSL stands for Extensible Stylesheet Language. XSLT stands for XSL Transformations. XSLT is used to convert XML documents to other formats like HTML, word, etc.
There are three major parts of XSL.

1) XSLT- to transform XML document,
2) XPath - to navigate through XML
3) XSL-FO- to format XML document

XSLT is more important for us. Xslt is used to transform XML document to another type of document like HTML. It is supported by all major browsers.

Consider CSS( cascading style sheet) is used to transform HTML document. It is used to give a look and feel to HTML tags. Consider below example.


span
{
background-color:red;
}

Above example gives red back ground color to each span tag. Same way XSLT is used for XML document. Consider above company information XML. If we directly view this XML file in a browser, It does not look good. We can use XSLT to transform this XML document. Like If I want to display company name in bold in align it to center. We can use following XSLT code.


<xsl:template match="CompanyName">
<tr align="center">
<th>
<xsl:apply-templates/>
</th>
</tr>
</xsl:template>

It will display CompanyName in bold and align it to center. We can add reference of XSL file in XML file as follows.


Some useful XSL templates

1) <xsl:template>

It is used to build XSL template. It has many attributes. Here we can specify XML element like in an above example, we have specified "CompanyName". match= "\" specifies root tag.

2) <xsl:apply-templates>

It is used to apply formatting. Like in above case we are applying formatting of table row and cell.

3) <xsl:value-of>

It is used to get value of XML element and use it in transformation.

4) <xsl:for-each>

It is used to loop through XML elements.

5) <xsl:if>

It is used to specify a certain conditions while transforming.

There are many more templates are available. For more information, you can visit w3schools website.

So in my project I have written XSL file with XSL Transfomation to get necessary formatting. I have created XML file from data stored in the sql server.

There is one class available in. Net framework 2.0 in System.Xml.Xsl name space, that is XslCompiledTransform. Using it, you can transform XML document as follows.


Dim xslt As New XslCompiledTransform
xslt.Load(Server.MapPath("~\") & "exp.xsl")
xslt.Transform(Server.MapPath("~\") & "testing.xml", Server.MapPath("~\") & "testing.html")
xslt.Transform(Server.MapPath("~\") & "testing.xml", Server.MapPath("~\") & "testing.doc")


Load method will load xsl style sheet. Transform method takes two arguments. First is XML file to be transformed and Output file.

This is how I have implemented word document automation. There is a limitation of it. We cannot create an Office 2007 word file that is .docx file. Because in Office 2007 Microsoft has introduced a totally new format that is Open Office XML. That I will discuss in my future blogs.