Designer

 Code On Time generator offers the ability to compose controllers from the results of custom SQL scripts.

The script can range in complexity from performing a simple “select *” from a table to any complicated SQL expression to combine fields from multiple tables.

Here is an example of a result set produced by an arbitrary SQL query.

In this example, we use a script that displays fields from tables Customers, Orders, Order Details, and Products by using joins on the foreign keys CustomerID, OrderID, and ProductID. The query can be seen below.

SELECT CompanyName, OrderDate, ProductName, Quantity 
    FROM Customers 
        JOIN Orders 
            JOIN [Order Details] 
                JOIN Products 
                ON [Order Details].ProductID = Products.ProductID 
            ON Orders.OrderID = [Order Details].OrderID 
        ON Customers.CustomerID = Orders.CustomerID 

Example output can be seen in the following picture.

Let’s generate a data controller for this query.

Start the web app generator and activate the Project Designer. In the Project Explorer, switch to the Controllers  tab. Click on the New Controller icon on the toolbar.

Give the controller a name:

Press OK to save the new controller. In the Project Explorer, right-click on the new controller and press “Generate From SQL…”.

The Define Data Controller window will open. Paste in the script at the beginning of this article. Press Verify and the result will be seen in the data grid, as in the picture below:

Select “Command Text” radio button. This will use the SQL script as a command and will take advantage of the application framework’s ability to compose SQL statements on the fly. SQL formulas will be defined for each field.

The “Base Table Name” property will be used in any dynamically created Insert and Update statements. Leave this property blank for now.

Keep default settings and press OK to define the data controller. The window will close and the Project Explorer will refresh with added fields, views, data fields, actions, as well as the command or business rules.

Next, we will need to create a page and bind the controller to the page with a data view. Right-click on the controller and press Copy.

Switch to the Pages tab in the Project Explorer. Click on the New Page icon.

Assign a name.

Press OK to save the page. Drag the new page in the Project Explorer to the right of Home page node to place it second in the site menu.

Right-click on the new page and press Paste to bind the controller to the page.

On the toolbar, press Browse to generate the app and open it in the default browser.

The result of the query will be visible on the page. The user can sort, filter, and view data.

Code On Time web app generator automatically creates controllers for any specified tables and views from your database. In addition, you can define new controllers from any SQL query. One can also choose to display data from any data source using C# or Visual Basic business rules – you are only limited by your imagination.

In this example, let’s request a list of articles recently published on /blog. A sample application showing the blog posts can be seen below.

The URL that will be used to compose a REST request is the following:

http://www.blogger.com/feeds/2297698770491701674/posts/default/

You can see an example of the response with the essential items highlighted below.

<?xml version='1.0' encoding='UTF-8'?>
<?xml-stylesheet href="http://www.blogger.com/styles/atom.css" type="text/css"?>
<feed xmlns='http://www.w3.org/2005/Atom' ...>
  ...
  <entry>
    ...
    <published>2014-07-13T22:25:00.000-07:00</published>
    <updated>2014-07-15T00:03:46.566-07:00</updated>
    ...
    <title type='text'>
      Map View, Master-Detail Pages, 
      Custom Result Sets, Client-Side APIs
    </title>
    <content type='html'>
      &lt;p&gt;&lt;a title="Code On Time generator creates line-of-business Web Apps ...
    </content>
    ...
  </entry>
  <entry>
    ...
    <published>2014-07-13T10:00:00.000-07:00</published>
    <updated>2014-07-13T17:11:25.294-07:00</updated>
    ...
    <title type='text'>Assigning a Theme to a Page</title>
    <content type='html'>
      &lt;p&gt;&lt;a title="Code On Time Generator is a premier web application ...
    </content>
    ...
  </entry>
  ...
</feed>

The code business rule will need to accept this XML, create a data table and convert each “entry” element into a data row. The data rows will have four columns – Published, Updated, Title, and Content.

Defining the Controller

The first step is to define a controller that will handle the data table. One possible way of defining the controller would be to simply create it in the Project Designer. However, let’s take advantage of the automatic field, view, data field, and action generation provided by the Define Data Controller tool.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab and press the New Controller icon.

Give the controller a name:

Press OK to save the new controller. Expand the new controller in the Project Explorer, and right-click on the Fields node. Select New Field option.

Define the following properties:

Press OK to save. Create another field with these properties:

Save the field, and add another:

Save, and add the Updated field:

Save the last field. Right-click on the controller, and press Generate From Fields.

This will proceed to generate views, data fields, actions, and several code business rules to override CRUD operations. No command will be created.

The first code business rule will provide an outline for defining the result set. The next three rules simply override the Insert, Update, and Delete actions and call PreventDefault() method. The developer must implement these rules in order for the respective actions to work.

On the toolbar, press Browse to regenerate the app and create the code files. When complete, right-click on Posts / Business Rules / Select (Code / Before) – GetData business rule, and press Edit Rule In Visual Studio.

The file will open in Visual Studio. The business rule will create a DataTable object by calling to CreatePostsDataTable() method. The default implementation of this method will simply return a data table with no data.

[Rule("GetData")]
public void GetDataImplementation(
    string title, 
    string content, 
    DateTime? published, 
    DateTime? updated)
{
    ResultSet = CreatePostsDataTable();
}
        
private DataTable CreatePostsDataTable()
{
    DataTable dt = new DataTable();
    dt.Columns.Add("Title", typeof(String));
    dt.Columns.Add("Content", typeof(String));
    dt.Columns.Add("Published", typeof(DateTime));
    dt.Columns.Add("Updated", typeof(DateTime));
    // 
    // Populate rows of table "dt" with data from any source 
    // (web service, file system, database, etc.)
    //
    return dt;
}

Let’s complete the implementation by providing the data for the data table. At the top of the file, add the following using/import directive:

C#:

using System.Xml;

Visual Basic:

Imports System.Xml

Then, replace the “Populate rows of table” comment after the data table is declared with the following code. The code will make a request to Blogger, read in each “entry” element and create a new data row in the table using the values of that element.

C#:

// get data into table
XmlReader reader = XmlReader.Create(
    "http://www.blogger.com/feeds/2297698770491701674/posts/default/");
reader.ReadToDescendant("entry");
while (reader.LocalName == "entry")
{
    DataRow r = dt.NewRow();
    XmlReader subtree = reader.ReadSubtree();

    if (subtree.ReadToDescendant("published"))
    {
        r["Published"] = subtree.ReadElementContentAsDateTime("published",
            "http://www.w3.org/2005/Atom");
        r["Updated"] = subtree.ReadElementContentAsDateTime("updated",
            "http://www.w3.org/2005/Atom");
        while (subtree.LocalName != "title")
            subtree.Read();
        r["Title"] = subtree.ReadElementContentAsString("title",
            "http://www.w3.org/2005/Atom");
        r["Content"] = subtree.ReadElementContentAsString("content",
            "http://www.w3.org/2005/Atom");

        dt.Rows.Add(r);
    }

    if (!reader.ReadToFollowing("entry") || reader.EOF)
        break;
}

Visual Basic:

Dim reader As XmlReader = XmlReader.Create(
                "http://www.blogger.com/feeds/2297698770491701674/posts/default/")
reader.ReadToDescendant("entry")
While reader.LocalName = "entry"
    Dim r As DataRow = dt.NewRow()
    Dim subtree As XmlReader = reader.ReadSubtree()

    If subtree.ReadToDescendant("published") Then
        r("Published") = subtree.ReadElementContentAsDateTime("published",
                                                              "http://www.w3.org/2005/Atom")
        r("Updated") = subtree.ReadElementContentAsDateTime("updated",
                                                            "http://www.w3.org/2005/Atom")
        While subtree.LocalName <> "title"
            subtree.Read()
        End While
        r("Title") = subtree.ReadElementContentAsString("title",
                                                        "http://www.w3.org/2005/Atom")
        r("Content") = subtree.ReadElementContentAsString("content",
                                                          "http://www.w3.org/2005/Atom")

        dt.Rows.Add(r)
    End If

    If Not reader.ReadToFollowing("entry") OrElse reader.EOF Then
        Exit While
    End If
End While

Make sure to save the file.

Adding the Page and Viewing the Results

Switch back to the Project Designer. Right-click on the Posts controller node, and press Copy.

Switch to the Pages tab in the Project Explorer. Click on the New Page icon.

Assign a name.

Press OK to save the page. Drag the new page in the Project Explorer to the right of Home page node to place it second in the site menu.

Right-click on the new page and press Paste to bind the controller to the page.

On the toolbar, press Browse to generate and open the web app in the default browser. The list of posts retrieved from the web service is displayed on the page. Note that you must define a primary key before any of the items can be selected.