Blog: Posts from September, 2008

Custom headers and footers can boost ease of use of your applications created with Data Aquarium Framework.  Take a look at the following screen shot.

Data field Unit Price features custom header and footer. Here is how we have defined this view in ~/Controllers/Products.xml of our sample application.

<view id="editForm1" type="Form" commandId="command1" label="Review Products">
  <headerText>Please review products information below. 
    Click Edit to change this record, click Delete to delete the record, 
    or click Cancel/Close to return back.</headerText>
  <categories>
    <category headerText="Products">
      <description>These are the fields of the products record 
        that can be edited.</description>
      <dataFields>
        <dataField fieldName="ProductName" columns="40" />
        <dataField fieldName="SupplierID" aliasFieldName="SupplierCompanyName" />
        <dataField fieldName="CategoryID" aliasFieldName="CategoryCategoryName" />
        <dataField fieldName="QuantityPerUnit" columns="20" />
        <dataField fieldName="UnitPrice" dataFormatString="c" columns="15">
          <headerText>Price of Unit:</headerText>
          <footerText>
            <![CDATA[ 
            <div style="color:navy">
            Enter price of unit in USD. Make sure to consult catalog of products 
            sold by our competitors at
            <a href="http://www.amazon.com" target="_blank">amazon.com</a>
            </div>]]>
          </footerText>
        </dataField>
        <dataField fieldName="UnitsInStock" columns="15" />
        <dataField fieldName="UnitsOnOrder" columns="15" />
        <dataField fieldName="ReorderLevel" columns="15" />
        <dataField fieldName="Discontinued" />
      </dataFields>
    </category>
  </categories>
</view>

HeaderText is displayed above the field value while the FooterText is displayed just under the field value. By default the field header is inherited from the label attribute of the base field.

You can break down the fields in the standard views in a few categories to further improve the form presentation.

Header and footer text will also automatically display in a custom form. Define the following markup in your web form that displays products.

<aquarium:DataViewExtender ID="ProductsExtender" runat="server" 
    Controller="Products" TargetControlID="ProductList" />
<div id="Products_editForm1" style="display: none">
    {ProductName}<br />
    {SupplierID}<br />
    {CategoryID}<br />
    {UnitPrice}
</div>

This simple markup will alter the form view presentation shown in the screen shot above to look like the one below.

Custom form templates allow ad hoc form view presentation when standard layout does not provide enough flexibility.

Data Aquarium Framework has introduced a new feature that allows developers and designers to affect presentation of data fields in grid and form views.

Generated applications are using a default theme for a consistent and efficient presentation. There will situations when you need to customize some screens without affecting the entire application. Consider the following illustration.

By default all columns values in the grid view are aligned horizontally to the left. You might want to have Unit Price column values aligned to the right and Discontinued flag to be centered.

Add a CSS stylesheet with default name to ~/App_Themes/MyCompany folder and enter the following text in its body.

table.DataView tr.Row td.UnitPrice,
table.DataView tr.AlternatingRow td.UnitPrice
{
    text-align: right;
    padding-right: 4px;
    background-color:Yellow;
    color:red;
}

table.DataView tr.HeaderRow th.UnitPrice a
{
    color:Blue;
}

table.DataView tr.Row td.Discontinued, table.DataView tr.AlternatingRow td.Discontinued
{
    text-align: center;
    background-color: #CCFFCC;
}

The first CSS rule definition will ensure that Unit Price column values are displayed on a yellow background, aligned to the right with a four pixel padding, and red font color.

The second rule will make a link in the header of the column Unit Price to be of blue color.

The third rule centers text and changes the background color of the Discontinued column.

How does it work?

Presentation of the grid is rendered in a client browser by Web.DataView component that can be found in  ~/Scripts/DataView.js. The presentation rendering code adds a field name to the list of classes on corresponding table cells of the view. Your custom CSS stylesheet can provide rules to take advantage of these classes.

It is important to name the stylesheet in such a way that is will be the last stylesheet of your application theme.

Here is a snippet of HTML generated for the sample page if you view the page source.

<head>
    .............
    <link href="App_Themes/MyCompany/Aquarium.css" type="text/css" 
        rel="stylesheet" />
    <link href="App_Themes/MyCompany/StyleSheet.css" type="text/css" 
        rel="stylesheet" />
    .............
</head>

Our stylesheet with default name Stylesheet.css follows the standard style sheet that comes with Data Aquarium Framework. These ensures that our CSS rules are going to override or extend those defined in the standard stylesheet.

Similar features are available in form views. If you need help in figuring out correct rules then please post a comment on this blog or drop us a line at http://www.codeontime.com/contactus.aspx.