Code On Time: Tutorials

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Tutorials

Monday, March 18, 2013Print Subscribe

Code On Time web applications automatically handle storage of binary large objects (BLOB). For example, the Northwind sample database contains pictures of each record in the Categories table. The web app displays the pictures in the grid and form views. Clicking on the thumbnail will download the picture.

Open the edit form for a category and edit the record. The control under the Picture thumbnail allows replacing or clearing the blob stored in the field.

Any type of file may be uploaded to the field. However, the file name and type is not stored by the database. When the user tries to download the file again, the user will receive a message similar to the one below.

The generic file name is “CategoriesPicture_1” and the content type is “.octet-stream”.

In order to preserve the file name and type, utility fields will be added to the Categories table.

Adding Utility Fields

Start SQL Server Management Studio. In the Object Explorer, right-click on Databases / Northwind / Categories and press Design.

Add the following columns:

Column Name	Data Type	Allow Nulls
PictureFileName	nvarchar(100)	true
PictureContentType	nvarchar(100)	true
PictureLength	int	true

Please note that these columns are case-sensitive. If the name of your field is “XXX”, the application framework will attempt to locate utility fields “XXXFileName”, “XXXContentType”, and “XXXLength”.

Save the changes to the table.

Refreshing the Project

Start the web application generator. Click on the project name and press Refresh. Select Categories controller and continue to refresh the project.

Viewing the Results

Continue to regenerate the web app. When complete, navigate to the Categories page. Select a record, and upload any non-image file.

Note that the three utility fields have automatically been updated. Click on the thumbnail to download the file. Note that the file name and type have been correctly added.

Labels: Application Builder, SQL Server, Tutorials, Web Application Generator

Wednesday, February 6, 2013Print Subscribe

SQLAnywhere 12 Sample Web Application

When Sybase SQLAnywhere 12 database server is installed, it will come with a sample database called “demo”. Let’s create a Web Site Factory application from this database.

Installing SQLAnywhere 12

First, download SAP Sybase SQL Anywhere 12 for Windows x64 from the Sybase website if you have not done so already.

Download the file and follow instructions to install the database server.

Creating the Web App

Start Code On Time web application generator. At the bottom of the page, click on Create a new web application link. On the New Project screen, select Web Site Factory.

Selecting Web Site Factory project to create.

Assign a name of “SQLAnywhereDemo”, pick the programming language of your choice, and press Create.

Press Next to reach the Database Connection page. From the Data Provider dropdown, select “.NET Framework Data Provider for SQL Anywhere 12”. Paste in your connection string in the field below.

Press Next twice to reach the Reporting page. Check the box to enable reporting.

The next page allows configuration of Custom Membership and Role Providers. Leave the default settings and press Next until you reach the Theme page. Select “Vantage” from the list.

Hold down Shift key and press Next to skip to the Summary page. Press Generate.

When generation finishes, the web application will open in the default browser.

Labels: Application Builder, SQL Anywhere, Tutorials, Web Application Generator

Wednesday, January 16, 2013Print Subscribe

“When Client Script” Property for Actions

Suppose that you have implemented the Order Form Sample with transactions using a “Status” field. The Status will partition “draft” orders from “committed” orders. However, the user may still navigate to the Orders page and change the values and details of a committed order.

Let’s prevent users from activating any Edit action when the Status field is set to “Committed”. This will be implemented with the help of “When Client Script” property. When the specified JavaScript expression evaluates to true, the action will be displayed. When it evaluates to false, the action will be hidden.

Adding Status Field

First, the Status field must be added to the controller so that the field value can be used in the JavaScript expression. Start the web application generator, and click on the project name. Press Refresh, and check the box next to Orders controller. Press Refresh, and confirm.

On the Summary page, click on Design to activate the Project Designer. In the Project Explorer, switch to the Controllers tab and expand Orders / Fields node. Drop Status (String(50)) node onto Orders / Views / grid1. The field will be instantiated as a data field in the view.

Double-click on Orders / Fields / Status (String(50)) node.

Mark the field as hidden.

Property	New Value
The field is hidden from users.	true

Press OK to save.

Hiding Edit Fields

In the Project Explorer, double-click on Orders / Actions / ag1 (Grid) / a2 – Edit action node.

Make the following change:

Property	New Value
When Client Script	[Status] != 'Committed'

Press OK to save.

Make the same change to Orders / Actions / ag2 (Form) / a1 – Edit action node, and Orders / Actions / ag4 (ActionBar) – Edit/Delete / a1 – Edit, editForm1 action node.

Viewing the Results

On the Project Explorer toolbar, press Browse. Navigate to Customers | Orders page.

Note that the Edit action is no longer available on the action bar or in the row context menu.

In addition, the form will no longer have an Edit button.

Labels: Application Builder, JavaScript, Tutorials, User Interface, Web Application Generator