Day 7- What is HTML Helpers

HTML Helpers are used to modify HTML output

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HTML Helpers

With MVC, HTML helpers are much like traditional ASP.NET Web Form controls.

Just like web form controls in ASP.NET, HTML helpers are used to modify HTML. But HTML helpers are more lightweight. Unlike Web Form controls, an HTML helper does not have an event model and a view state.

In most cases, an HTML helper is just a method that returns a string.

With MVC, you can create your own helpers, or use the built in HTML helpers.

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Standard HTML Helpers

MVC includes standard helpers for the most common types of HTML elements, like HTML links and HTML form elements.

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HTML Links

The easiest way to render an HTML link in is to use the HTML.ActionLink() helper.

With MVC, the Html.ActionLink() does not link to a view. It creates a link to a controller action.

Razor Syntax:

@Html.ActionLink("About this Website", "About")

ASP Syntax:

<%=Html.ActionLink("About this Website", "About")%>

The first parameter is the link text, and the second parameter is the name of the controller action.

The Html.ActionLink() helper above, outputs the following HTML:

<a href="/Home/About">About this Website</a>

The Html.ActionLink() helper has several properties:

Property	Description
.linkText	The link text (label)
.actionName	The target action
.routeValues	The values passed to the action
.controllerName	The target controller
.htmlAttributes	The set of attributes to the link
.protocol	The link protocol
.hostname	The host name for the link
.fragment	The anchor target for the link

Note: You can pass values to a controller action. For example, you can pass the id of a database record to a database edit action:

Razor Syntax C#:

@Html.ActionLink("Edit Record", "Edit", new {Id=3})

Razor Syntax VB:

@Html.ActionLink("Edit Record", "Edit", New With{.Id=3})

The Html.ActionLink() helper above, outputs the following HTML:

<a href="/Home/Edit/3">Edit Record</a>

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HTML Form Elements

There following HTML helpers can be used to render (modify and output) HTML form elements:

• BeginForm()
• EndForm()
• TextArea()
• TextBox()
• CheckBox()
• RadioButton()
• ListBox()
• DropDownList()
• Hidden()
• Password()

ASP.NET Syntax C#:

<%= Html.ValidationSummary("Create was unsuccessful. Please correct the errors and try again.") %>
<% using (Html.BeginForm()){%>
<p>
<label for="FirstName">First Name:</label>
<%= Html.TextBox("FirstName") %>
<%= Html.ValidationMessage("FirstName", "*") %>
</p>
<p>
<label for="LastName">Last Name:</label>
<%= Html.TextBox("LastName") %>
<%= Html.ValidationMessage("LastName", "*") %>
</p>
<p>
<label for="Password">Password:</label>
<%= Html.Password("Password") %>
<%= Html.ValidationMessage("Password", "*") %>
</p>
<p>
<label for="Password">Confirm Password:</label>
<%= Html.Password("ConfirmPassword") %>
<%= Html.ValidationMessage("ConfirmPassword", "*") %>
</p>
<p>
<label for="Profile">Profile:</label>
<%= Html.TextArea("Profile", new {cols=60, rows=10})%>
</p>
<p>
<%= Html.CheckBox("ReceiveNewsletter") %>
<label for="ReceiveNewsletter" style="display:inline">Receive Newsletter?</label>
</p>
<p>
<input type="submit" value="Register" />
</p>
<%}%>