Blog: Posts from October, 2016

Data fields displayed in forms of applications created with Code On Time are organized in categories. By default, all data fields are rendered top down in a single category. It is possible to use categories to enable the rendering of data fields in multiple columns, tabs, a wizard, or a combination thereof.

Each category is rendered with a bar at the top displaying the header text. When the user presses on the bar, the category will collapse or reveal itself. The categories’ Description property is displayed underneath the collapsible bar. Data fields belonging to the category are rendered in row containers, with the label on the left side, and the input control on the right side.

Let’s configure the Employees page of the Northwind sample project into multiple categories, and customize the descriptions for each category. We will display the field values in the category descriptions in order to provide context to the user.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Double-click on “Employees / Views / editForm1 / c1 – Employees” category node.

Make the following changes.

Press OK to save. Next, create a new category by right-clicking “Employees / Views / editForm1” and press New Category.

Configure as follows and press OK to save the category.

Create another category with the following properties. Notice the use of field names wrapped in curly brackets. The text will be updated at runtime with the field values.

Finally, use drag & drop to reposition the data fields in the correct categories, as shown in the picture below.

On the toolbar, press Browse to generate the application. When the application comes up in your browser, navigate to the Employees page and select a record. Notice that the data fields have been rendered in two tabs, with the first tab displaying two columns. Each category displays the specified category description.

Switching to the second tab will display the “Address Info” category. Notice that the fields in curly brackets have been replaced with the field values.

Note that the same functionality is available in Desktop user interface.

In custom form templates, category descriptions can be added by inserting a row container, with a description control inside. Field values can be displayed by using a “field” control marked as read-only.

<div data-container="collapsible" data-header-text="Address Info">
    <div data-container="row">
        <div data-control="description">
            Where does 
            <span data-control="field" data-field="FirstName" data-read-only="true"></span>
            <span data-control="field" data-field="LastName" data-read-only="true"></span>
            live ?
        </div>
    </div>
    ...
</div>

Conditional visibility on data fields and categories allows hiding or showing page elements based on field values. View templates give the ability to define custom presentations. When a custom template is defined for the view, the client library is not able to determine which page elements should be displayed or hidden based on the conditional visibility expressions. As such, the creator of view templates must mark up the template in order to bind these expressions with the correct elements.

When the template has been correctly defined, data fields, categories, and even custom page elements will be able to displayed or hidden depending on field values. For example, a large label is displayed in the sample below when the order has been shipped past the required date.

Let’s use the create form for Orders in the Northwind sample database.

Arranging Data Fields into Categories

First, let’s rearrange the data fields into multiple categories, in order to control visibility of each category, instead of each individual data field. The user will only be able to enter shipping information if a shipped date is assigned.

Start the Project Designer. In the Project Explorer, switch to the Controllers tab. Right-click on “Orders / createForm1” view node, and press New Category.

Define the following settings:

$row.ShippedDate != null

Press OK to save the category. Next, drag data fields ShipVia, Freight, ShipName, ShipAddress, ShipCity, ShipRegion, ShipPostalCode, and ShipCountry into the new category.

Adding Data Field Visibility

Users should not be able to set the shipped date until the order date has been set. Let’s add a data field conditional visibility expression to ShippedDate data field.

Double-click on “Orders / Views / createForm1 / c1 – New Orders / ShippedDate” data field node.

Make the following change:

$row.OrderDate != null

Press OK to save the data field.

Adding the View Template

Let’s add a custom view template for editForm1 of Orders controller.

On the toolbar, press Develop to open the project in Visual Studio. In the Solution Explorer, right-click on the “WebSite” node and press “Add / New Folder”.

Give this new folder the name “Views”. Next, right-click on the folder and press “Add / HTML Page”.

Give this page the name “Orders.createForm1.html”. Replace the contents of the file with the following:

<div data-container="collapsible" data-header-text="New Order">
    <div data-container="row">
        <div data-control="description">Enter new order information below.</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="CustomerID">CustomerID</div>
        <div data-control="field" data-field="CustomerID">CustomerID</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="EmployeeID">EmployeeID</div>
        <div data-control="field" data-field="EmployeeID">EmployeeID</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="OrderDate">OrderDate</div>
        <div data-control="field" data-field="OrderDate">OrderDate</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="RequiredDate">RequiredDate</div>
        <div data-control="field" data-field="RequiredDate">RequiredDate</div>
    </div>
    <div data-container="row" data-visibility="f:ShippedDate">
        <div data-control="label" data-field="ShippedDate">ShippedDate</div>
        <div data-control="field" data-field="ShippedDate">ShippedDate</div>
    </div>
    <div data-container="row" data-visible-when="$row.RequiredDate < $row.ShippedDate">
        <h3 style="color:red">WARNING: THIS ORDER HAS BEEN SHIPPED LATE</h3>
    </div>
</div>
<div data-container="collapsible" data-header-text="Ship Info" data-visibility="c:c2">
    <div data-container="row">
        <div data-control="description">Enter shipping information below.</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="ShipVia">ShipVia</div>
        <div data-control="field" data-field="ShipVia">ShipVia</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="Freight">Freight</div>
        <div data-control="field" data-field="Freight">Freight</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="ShipName">ShipName</div>
        <div data-control="field" data-field="ShipName">ShipName</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="ShipAddress">ShipAddress</div>
        <div data-control="field" data-field="ShipAddress">ShipAddress</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="ShipCity">ShipCity</div>
        <div data-control="field" data-field="ShipCity">ShipCity</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="ShipRegion">ShipRegion</div>
        <div data-control="field" data-field="ShipRegion">ShipRegion</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="ShipPostalCode">ShipPostalCode</div>
        <div data-control="field" data-field="ShipPostalCode">ShipPostalCode</div>
    </div>
    <div data-container="row">
        <div data-control="label" data-field="ShipCountry">ShipCountry</div>
        <div data-control="field" data-field="ShipCountry">ShipCountry</div>
    </div>
</div>

Notice that there are three highlighted pieces in the sample above.

The yellow highlight shows how to apply data field-level visibility to an element by using the attribute “data-visibility”, and setting the value to “f:” followed by the name of the field. This will inherit the visibility from the field “ShippedDate”.

The green highlight shows how to apply category-level visibility to an element. Use the attribute “data-visibility”, and set the value to “c:” followed by the category ID. The example will inherit visibility from the category “c2”.

The orange highlight shows how to use custom JavaScript expressions to set visibility. Use the attribute “data-visible-when”, and set the value to your JavaScript visibility expression.

Switch back to the browser, navigate to the Orders page, and create a new order. Notice that the OrderDate data field, custom header, and shipping category are hidden.

Enter a value for Order Date. Notice that the Shipped Date data field will appear.

Enter a value for Shipped Date. The Ship Info category will appear.

If the Shipped Date is after the Required Date, the warning text will appear.