When you add a label to the canvas, you can add an expression or a field from the datamodel. You can use any expression within a label using the expression editor and the result will be displayed as Text (by default). This means you can show plain text by using the "quotes" but also use a expression to show a non static text. When a label is added to the template a expression editor appears, this is where you insert the expression that will yield the result to display as label. When a label is added you can change its properties - based on the resulting type of the expression, the available properties will vary!
The When empty property lets you set a value to show when the Expression returns an empty value.
The appearance properties changes the way a user will see the label. This setting can be used to give the label a bit of extra functionality.
For an expression that yields a (plain) text-value, you can choose between text, a hyperlink, an email or as HTML formatted text. When hyperlink or email is chosen, the label will be displayed as clickable link and will perform the approproate action (try to open the link in the browser or start the email program to create a new message with the value from the label as To: recipient).
The different settings for a Text-label could look like this:
Based on the resulting type of the expression, the display options may vary:
Text as described above;
Boolean/YesNo: no other display options;
Single/Multi Select (concepts): no other display options;
Date/Time/Duration: you can set a display format, how to show the value according to specified format;
Entity/Reference: no other display options;
File: display as hyperlink (shows a link to click and download the file - additionally set the display text or leave empty to show the filename) or as image (only useful when file is indeed an image - additionally select rendering options as described at the image element);
Number: set a numeric format, set the number of decimals to show (default none).
Rich Text: display as Text or as HTML. When the rich text value contains formatting, set the display to HTML to allow that formatting to be displayed. Default display is set to Text which will show the Rich Text as Plain Text...
Finally, the Prefix and Postfix options allow you to add text (plain text - either with a fixed value or more dynamic by using an expression) that will be added directly before or after the label itself. Not available for File labels.
The label's appearance, in addition to the default options accessible from the properties pane, can also be changed using the style section of the toolbar. With these options, you can modify various aspects such as text style, boldness, alignment, indentation, and more. Labels can also be changed into hyperlinks and given a tooltip by enabling tooltip properties in the property pane.
