Combo Box control

Use this control to add a Combo Box that enables users to click a button and select from a drop-down list. The items in the list are associated with a database field or variable. Users can also type in a value if the check box in the selectonly property is cleared (set to false).

Search for	Example	Results
A single word	`cat`	Topics that contain the word "cat". You will also find its grammatical variations, such as "cats".
A phrase. You can specify that the search results contain a specific phrase.	`"cat food"` (quotation marks)	Topics that contain the literal phrase "cat food" and all its grammatical variations. Without the quotation marks, the query is equivalent to specifying an OR operator, which finds topics with one of the individual words instead of the phrase.

Search for	Operator	Example
Two or more words in the same topic	`AND` `and` `+` (plus symbol) `&` (ampersand)	`cat AND dog` `"cat food"+milk` `"cat food"&"dog food"`
Either word in a topic	`OR` `or` `\|` (pipe)	`cat OR dog` `cat \| dog`
Topics that do not contain a specific word or phrase	`NOT` `not` `!` (exclamation point)	`NOT cat` `! dog`
Topics that contain one string and do not contain another	`^` (caret)	`cat ^ mouse`
A combination of search types	`( )` parentheses	`cat + (dog \| mouse)` `cat \| dog + (! mouse)`

To place a Combo Box on a form, click Combo Box and then click the form.
Be sure to put the name of the database field or variable that you want to associate with this control into the Input property.

Best practice

Use eight drop–down lines unless the drop–down set contains a fixed number of elements less than or equal to seven, in which case the number of lines should be equal to the number of elements in the drop–down set.

Property	Usage
Name	Specify a unique identifier for the object on the screen. (Optional) This name is used by external applications, such as RAD, to dynamically change the properties of the object.
X	Specify the object’s horizontal position based on the left edge of the object.
Y	Specify the object’s vertical position based on the top edge of the object.
Width	Specify the width of the object in alignment grid units.
Height	Specify the height of the object in alignment grid units.
Visible	Select this option to make the object visible on the form. Clear the check box to hide the object from view on the form.
Visible Condition	Specify an expression to override the Visible property when that expression evaluates to true.
Caption	Specify a text caption for the object.
Caption Condition	Specify an expression to override the Caption property when that expression evaluates to true.
Input	Specify the database field or variable to associate with this control.
Accessible Name	Specify a component name for use with accessibility software. (Optional) Note: This function is only supported by the Web client. If no name is present, the Web client defaults to looking for a nearby label to use for the name of the component. For buttons, check boxes, or radio buttons, it uses the component’s text. Accessibility software can query the Web client to get this information and use it to present data to the user in a variety of ways. For example, speech simulation software says the name and the type of component when the component has focus.
Accessible Description	Specify a component description for use with accessibility software. (Optional) Note: This function is only supported by the Web client. If no description is present, the Web client defaults to looking for a nearby label to use for the name of the component. For buttons, check boxes, or radio buttons, the Web client will use the component’s text. Accessibility software can query the Web client to get this information, and use it to present it to the user in a variety of ways. For example, when a component gets focus, speech simulation software will say the name and the type of component, based on the settings in the Accessible Name and Accessible Description fields.
Tab Stop	Specify the tab sort order for this field. By default, the TAB key navigates the focus on a form from top to bottom and left to right. Objects that have a non-zero Tab Stop are visited first, in ascending order. For a button, file, radio button or check box, you will almost always use the default of 0.
Read-Only	Select this option to disable editing capabilities and provide only viewing access to the field. Give read–only fields a tab–stop value of –1 to prevent users from tabbing into them.
Read-Only Condition	Specify an expression to override the Read-Only property when that expression evaluates to true.
Mandatory	Select this option so that a red asterisk indicating a required field is displayed. This is a visible change only. - To make the field mandatory for any form it appears on, use the System Definition Utility. - To make the field mandatory for a small number of forms only, use Format Control.
Mandatory Condition	Specify an expression to override the Mandatory property when that expression evaluates to true.
Array Length	Specify the size of the scrolling region used to view array entries. A scroll bar appears beside the fields to allow users to view the array entries. - If a field is assigned an Array Length of 5, the form stacks five fields vertically to allow users to view the five array entries. - If Array Length is set to -1, the form dynamically creates as many fields as there are entries in the array. - If the Input data type is scalar, only a single text box appears. Note: The screen object must be associated with an array data structure. The default is 0, which means one vertical line of information appears.
Password	Select this option to make the text entered in the field a series of asterisks on the screen. The data is not encrypted, just transposed.
Maximum Chars	Specify the number of characters the user can enter in the field. The default is 0 (unlimited).
Maximum Characters Beep	Select this option to notify the user by sounding a beep that they reached the maximum number of characters.
Case Conversion	Specify how to change the case of text entered in the field. The choices are None, Upper, Lower.
Decimals	Specify the number of decimal points for numbers in this field. Service Manager modifies numbers entered in the field to the number of decimal points you specify.
Parse	Select this option to verify that the text entered in a field is the correct syntax. The syntax for the field is defined by the type of field it displays (date, expression, number, and so forth).
Data Changed Event	Specify the option number (such as Button ID) to call if the data contained in the object changed. This sends an event to the display RAD application.
Value List	In conjunction with the Input property, defines how the Display List values are identified in the database. Value and Display Lists are entered using the Edit List dialog box. You can enter hard coded entries for each list, or you can supply a variable as the first and only entry. The run time values of the variable are used to populate these lists. This property is supported only in association with the toolbar configuration Knowledge Management Extended, which is not intended to be used outside of the out-of-box Knowledge Management module. Note: When defining Value List and Display List properties, you should avoid using the following reserved characters: semicolon (;) tab key newline (carriage return) form feed backspace equal sign (=) Important: Do not use keys (like backspace), as the system cannot process their ASCII representation entries correctly which causes unpredictable results.
Value List Condition	Specify an expression to override the property when that expression evaluates to true.
Display List	Specify the values that appear in the drop-down list at run time. There must be a one–to–one correspondence between the values for Value List and for Display List. If the Display List is the only populated property, the display values are written to the database. This property is supported only in association with the toolbar configuration Knowledge Management Extended, which is not intended to be used outside of the out-of-box Knowledge Management module. Note: When defining Value List and Display List properties, you should avoid using the following reserved characters: semicolon (;) tab key newline (carriage return) form feed backspace equal sign (=) Important: Do not use keys (like backspace), as the system cannot process their ASCII representation entries correctly which causes unpredictable results.
Display List Condition	Specify an expression to override the Display List property, when the expression evaluates to True.
Box Lines	Specify the window size of the drop-down list.
Select Only	Select this option to require the user to select from the Combo Box drop-down list. If the user makes a manual entry, the value must already exist in the drop-down list (defined in the Value List and Display List properties). Clear this option to allow the user to select from the drop-down list or to manually enter a value.

Property

Usage

Name

Specify a unique identifier for the object on the screen. (Optional)

This name is used by external applications, such as RAD, to dynamically change the properties of the object.

Specify the object’s horizontal position based on the left edge of the object.

Specify the object’s vertical position based on the top edge of the object.

Width

Specify the width of the object in alignment grid units.

Height

Specify the height of the object in alignment grid units.

Visible

Select this option to make the object visible on the form. Clear the check box to hide the object from view on the form.

Visible Condition

Specify an expression to override the Visible property when that expression evaluates to true.

Caption

Specify a text caption for the object.

Caption Condition

Specify an expression to override the Caption property when that expression evaluates to true.

Input

Specify the database field or variable to associate with this control.

Accessible Name

Specify a component name for use with accessibility software. (Optional)

Note: This function is only supported by the Web client.

If no name is present, the Web client defaults to looking for a nearby label to use for the name of the component. For buttons, check boxes, or radio buttons, it uses the component’s text. Accessibility software can query the Web client to get this information and use it to present data to the user in a variety of ways. For example, speech simulation software says the name and the type of component when the component has focus.

Accessible Description

Specify a component description for use with accessibility software. (Optional)

Note: This function is only supported by the Web client.

If no description is present, the Web client defaults to looking for a nearby label to use for the name of the component. For buttons, check boxes, or radio buttons, the Web client will use the component’s text. Accessibility software can query the Web client to get this information, and use it to present it to the user in a variety of ways. For example, when a component gets focus, speech simulation software will say the name and the type of component, based on the settings in the Accessible Name and Accessible Description fields.

Tab Stop

Specify the tab sort order for this field. By default, the TAB key navigates the focus on a form from top to bottom and left to right. Objects that have a non-zero Tab Stop are visited first, in ascending order. For a button, file, radio button or check box, you will almost always use the default of 0.

Read-Only

Select this option to disable editing capabilities and provide only viewing access to the field. Give read–only fields a tab–stop value of –1 to prevent users from tabbing into them.

Read-Only Condition

Specify an expression to override the Read-Only property when that expression evaluates to true.

Mandatory

Select this option so that a red asterisk indicating a required field is displayed. This is a visible change only.
- To make the field mandatory for any form it appears on, use the System Definition Utility.
- To make the field mandatory for a small number of forms only, use Format Control.

Mandatory Condition

Specify an expression to override the Mandatory property when that expression evaluates to true.

Array Length

Specify the size of the scrolling region used to view array entries. A scroll bar appears beside the fields to allow users to view the array entries.
- If a field is assigned an Array Length of 5, the form stacks five fields vertically to allow users to view the five array entries.
- If Array Length is set to -1, the form dynamically creates as many fields as there are entries in the array.
- If the Input data type is scalar, only a single text box appears.

Note: The screen object must be associated with an array data structure.

The default is 0, which means one vertical line of information appears.

Password

Select this option to make the text entered in the field a series of asterisks on the screen. The data is not encrypted, just transposed.

Maximum Chars

Specify the number of characters the user can enter in the field. The default is 0 (unlimited).

Maximum Characters Beep

Select this option to notify the user by sounding a beep that they reached the maximum number of characters.

Case Conversion

Specify how to change the case of text entered in the field. The choices are None, Upper, Lower.

Decimals

Specify the number of decimal points for numbers in this field.
Service Manager modifies numbers entered in the field to the number of decimal points you specify.

Parse

Select this option to verify that the text entered in a field is the correct syntax. The syntax for the field is defined by the type of field it displays (date, expression, number, and so forth).

Data Changed Event

Specify the option number (such as Button ID) to call if the data contained in the object changed. This sends an event to the display RAD application.

Value List

In conjunction with the Input property, defines how the Display List values are identified in the database. Value and Display Lists are entered using the Edit List dialog box. You can enter hard coded entries for each list, or you can supply a variable as the first and only entry. The run time values of the variable are used to populate these lists.

This property is supported only in association with the toolbar configuration Knowledge Management Extended, which is not intended to be used outside of the out-of-box Knowledge Management module.

Note: When defining Value List and Display List properties, you should avoid using the following reserved characters:

semicolon (;)
tab key
newline (carriage return)
form feed
backspace
equal sign (=)

Important: Do not use keys (like backspace), as the system cannot process their ASCII representation entries correctly which causes unpredictable results.

Value List Condition

Specify an expression to override the property when that expression evaluates to true.

Display List

Specify the values that appear in the drop-down list at run time. There must be a one–to–one correspondence between the values for Value List and for Display List. If the Display List is the only populated property, the display values are written to the database.

This property is supported only in association with the toolbar configuration Knowledge Management Extended, which is not intended to be used outside of the out-of-box Knowledge Management module.

Note: When defining Value List and Display List properties, you should avoid using the following reserved characters:

semicolon (;)
tab key
newline (carriage return)
form feed
backspace
equal sign (=)

Important: Do not use keys (like backspace), as the system cannot process their ASCII representation entries correctly which causes unpredictable results.

Display List Condition

Specify an expression to override the Display List property, when the expression evaluates to True.

Box Lines

Specify the window size of the drop-down list.

Select Only

Select this option to require the user to select from the Combo Box drop-down list. If the user makes a manual entry, the value must already exist in the drop-down list (defined in the Value List and Display List properties).

Clear this option to allow the user to select from the drop-down list or to manually enter a value.

Related concepts