Generally while designing a CMS we found this situation (Generate Dynamic HTML) to handle. Let us assume we have records in Database. From those records we required to Create HTML pages dynamically. Here I did the same using VB.NET File Operations.
Look at the below Codes from my Code behind file. Here I have 2 functions & page load event. During page load I am calling the function CreatePage(). CreatePage function accepts 3 parameters page title, HTML text here I mean contents for HTML page & The file name I want to create physically.
VB.NET CreatePage function to Generate Dynamic HTML
Inside CreatePage function I am concatenating a string with HTML format. In head tag I am adding the page title. Then entering a new-line character. Similarly did for title & body content. Not doing the File Operations here. For file operation I have one more separate function SaveTextToFile(). SaveTextToFile accepts 2 parameters. First parameter is the HTML string we concatenating in CreatePage function. Second one is the file path. File path means where to Create the HTML page.
To Create file physically here I referred System.IO & StreamWriter method. After Create Instance I am using Write method. Including this I have a boolean variable. Which helps to know whether the file created successfully or not. This variable default value is false. Just after StreamWriter Write method I am updating this variable.
Generate Dynamic HTML using VB.NET Codes
Imports System.IO
Partial Class _CreateHtml
Inherits System.Web.UI.Page
Public Sub CreatePage(ByVal HTMLTitle As String, ByVal HTMLText As String, ByVal HTMLFileName As String)
Dim strFile As String
strFile = ""
'Constructing the String strFile
strFile = "<html>" & vbNewLine
strFile = strFile & "<head>" & vbNewLine
strFile = strFile & "<title>" & HTMLTitle & "</title>" & vbNewLine
strFile = strFile & "</head><body>" & vbNewLine
strFile = strFile & HTMLText & vbNewLine
strFile = strFile & "</body></html>"
'Calling SaveTextToFile function for IO Operation
SaveTextToFile(strFile, Server.MapPath(".") & "\HTMLFiles\" & HTMLFileName & ".html")
End Sub
Public Function SaveTextToFile(ByVal strData As String, ByVal FullPath As String, Optional ByVal ErrInfo As String = "") As Boolean
Dim Contents As String
Dim Saved As Boolean = False
'Using StreamWriter to Create File
Dim objReader As IO.StreamWriter
Try
objReader = New IO.StreamWriter(FullPath)
objReader.Write(strData)
objReader.Close()
Saved = True
Catch Ex As Exception
Response.Write(Ex.Message)
End Try
Return Saved
End Function
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
CreatePage("Title goes here", "Hello world! This is a HTML file Created from Code Behind.", "Sample")
End Sub
End Class
Introduction to Generate Dynamic HTML (DHTML)
Unlike static HTML, which presents fixed content, DHTML allows elements on a webpage to change dynamically without requiring a full page reload. This interactivity is achieved through a combination of HTML, Cascading Style Sheets (CSS), JavaScript, and the Document Object Model (DOM).
For example, drop-down menus, form validations, and drag-and-drop interfaces are often powered by DHTML. The key advantage is that content modifications happen on the client side, reducing server requests and improving performance.
Core Components of DHTML
1. HTML (HyperText Markup Language) HTML forms the backbone of any webpage, defining the structure and content. In DHTML, HTML elements serve as the foundation upon which dynamic behaviors are applied. Elements like `
`, “, and forms are frequently manipulated using JavaScript and CSS to create interactive effects.
2. CSS (Cascading Style Sheets) CSS controls the presentation of HTML elements, including layout, colors, fonts, and animations. In DHTML, CSS is used to modify styles dynamically. For instance, JavaScript can change CSS properties to hide or show elements, adjust dimensions, or apply transitions.
3. JavaScript JavaScript is the scripting language that enables dynamic behavior. It interacts with the DOM to manipulate HTML and CSS in real-time. Functions like `document.getElementById()` allow developers to select and modify elements, while event listeners (e.g., `onclick`, `onmouseover`) trigger these changes based on user actions.
How DHTML Works
DHTML operates by combining these technologies in the following way:
User Interaction Triggers an Event – A user action, such as clicking a button or hovering over an element, generates an event.
JavaScript Handles the Event – An event listener in JavaScript detects the action and executes a corresponding function.
DOM Manipulation Occurs – The function modifies the DOM, changing HTML content or adjusting CSS properties.
Browser Renders Changes Instantly – The updated DOM is re-rendered by the browser, displaying the changes to the user.
Common Applications of DHTML
1. Drop-Down Menus Navigation menus that expand or collapse based on user clicks are powered by DHTML, improving site usability.
2. Drag-and-Drop Interfaces Web applications like Trello or file uploaders use DHTML to allow users to drag elements across the screen.
3. Dynamic Content Loading Single-page applications (SPAs) use DHTML to load new content without refreshing the page, providing a seamless browsing experience.
4. Animations and Effects Subtle animations, such as fading elements or sliding panels, enhance visual appeal and guide user attention.
Best Practices for Implementing DHTML
Optimize Performance – Excessive DOM manipulation can slow down a webpage. Use efficient selectors and minimize reflows.
Ensure Accessibility – DHTML elements should remain usable for screen readers and keyboard navigation.
Graceful Degradation – Design webpages to function even if JavaScript is disabled, ensuring broader compatibility.
Cross-Browser Testing – Verify that DHTML features work across different browsers and devices.
Use Modern Frameworks – Libraries like jQuery, React, and Vue.js simplify DHTML implementation and improve maintainability.
Future of DHTML
As web technologies evolve, DHTML continues to integrate with modern frameworks and APIs. Web Components, for example, allow reusable custom elements with encapsulated functionality. Additionally, advancements in CSS (like Grid and Flexbox) and JavaScript (ES6+) enable more sophisticated dynamic behaviors.
The rise of progressive web apps (PWAs) and real-time web applications further emphasizes the importance of DHTML in delivering fast, interactive experiences.
Conclusion
Dynamic HTML remains a fundamental technology for creating engaging, interactive web applications. By leveraging HTML, CSS, JavaScript, and the DOM, developers can build responsive interfaces that enhance user experience while reducing server dependency. As web standards advance, DHTML will continue to evolve, offering even more powerful tools for modern web development.
