Collections as Data Sources for Controls
Some control types can load required data from the database themselves, assuming Database was selected as data source.
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The control type Tree load data from a database table depending on hierarchy level. First of all, the root level is loaded; the second level is loaded by expanding a node and so on.
- The control type Grid loads data depending on the selected page. If, for example, 20 entries are displayed per page, then initially only the first 20 database objects are loaded from the database.
This reduces memory usage and the control can be displayed faster.
Collection Events
You can define actions to be executed if a specified operation is applied to the collection data. Events can be triggered by the following.
| Operation | Description |
|---|---|
| Insert | A single row was added to the collection. |
| Delete | A single row was deleted from the collection. |
| Update |
A single collection data value was updated. |
| Bulk | A set of rows was added to the collection or deleted from it. |
To define an event
- Select a module or component in the navigation view.
- Mark the Events node in the definition tree view and select Object in extension | Event handling from the context menu.
The view switches to Configuration (custom) and the new Insert subnode is selected. In the Node editor view, you can manage the following settings.
Table 57: Settings for event handling Setting Description Identifier (optional) Enter the name for the event. Operation* Select one of the operations listed above. Collection* Select a collection in the option box. You can navigate to the selected collection using and apply further settings if necessary.
Control-ID* A Control-ID is preset. You can overwrite this. - Adjust any settings you need to and then click
in the toolbar.
To define an expression-based event
- Select a module or component in the navigation view.
- Mark the Events node in the definition tree view and select Object in extension | Expression-based event from the context menu.
The view switches to Configuration (custom) and the new subnode is marked. In the Node editor tab, you can manage the following settings.
- Open the SQL input field at the Value* box using
.
- Enter a value for the expression-based event and click Apply.
- Save with
Assigning Collections to Components
Before you can assign a collection to a component, you must prepare the custom component to make it suitable for the collection.
To do this, the component requires a "virtual collection", which you will find under the component’s Property node in the definition tree view. Collections are assigned in the "virtual collection".
"Virtual collections" defined on components are marked as compulsory or optional.
Compulsory "virtual collections" must be assigned to a location collection. This assignment is made where the component's usage is defined.
Before you assign a collection to a component, a node must be configured under Collection mapping under the component.
Collection mapping nodes are automatically assigned when a component reference is added. These nodes are added automatically but not configured. You configure them in the Node editor view. You can also add a Collection mapping node with the help of a wizard that you can call from the context menu. Another option for adding these nodes, is to add a single node that you can also access through the context menu of your component in the definition tree view.
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NOTE: The following instruction steps are based on an example of a direct container reference. |
To assign a collection to a component
- Select the tab of the component or module in the definition tree view, in which you want to use a Container-type component.
- Mark a Container-type node and select Component reference | Container (reference) from the context menu.
NOTE: If you add a component reference, the subnodes for collection mapping are automatically added. If more nodes are required for collection mapping, you can either add a Collection mapping type node yourself or by using the wizard. Other nodes may be added when you add a node with the wizard. You can delete these afterward.
- Select the component you want to reference in the Identifier option box in the Node editor view.
- Select the Collection mapping node in the definition tree view.
- Select the relevant collection under Virtual collection in the Node editor view.
- Select the collection you want in the Map to local collection box.
To define a virtual collection for a user defined component
- Select a custom component to which you want to assign a collection.
This displays the object in the definition tree view.
- Mark the Properties node in the definition tree view and select Virtual collection from the context menu.
A new virtual collection is added in the definition tree view.
- Enter a name for the virtual collection in the Identifier box in the Node editor view.
Note: Use the Object type and Cursor required options to limit collection assignment further. Use the Object type option to ensure that the assigned collection must be a database collection of the given type. Use the Cursor required option to specify the point of the assigned collection which must be within an iteration above this.
Declaring Configuration Keys in Modules and Components
To declare a configuration key for a module or a component
- Click
in the definition tree view and select the Configuration node.
- Select Configuration section in the context menu.
- Mark the new configuration section in the definition tree view.
You can see that the new configuration section is selected with empty fields in Node editor.
- Enter the name for the new configuration section in the Identifier and Description input fields in Node editor view.
The configuration section is displayed with its name in the definition tree view.
- Mark the configuration section.
- Select Parameter from the context menu.
The new parameter is added under the configuration section.
- Mark the new parameter.
- Enter a name for the configuration key in the Key text field.
- Example of a configuration key name: CCC_ConfigParm_Hyperview_HR
- Enter the name given in the Key input field in the Identifier text field as follows:
- Example for input: translate('#LDS#HR_Hyperview_Colums')
- In the Description text field, enter the following text that should appear in the Settings... view under Details.
- Example for input: translate('#LDS#Choose Columns for HR-Hyperview')
- Select the parameter type in Type and edit the configuration key as in the sections about parameter types.
Note: You may have to edit further settings depending on which parameter type you selected.