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Freon offers a number of different ways to display a boolean value, ranging from textual to visual controls, like a switch. Each option is described in the following.

Note that you can set a default for the display of a boolean value in the global section of the default editor. See Global Projections.

The strings displayed for boolean values — normally true and false — can be customized. In the projection two strings are added, the first is the text that represents the true-value, the second represents the false-value.

In the next example, the concept InsurancePart has a simple property of type boolean called isApproved. In the projection for isApproved the strings JA and NEE will be shown for, respectively, true and false.

// Insurance/src/defs/language-main.ast#L41-L49

// An InsurancePart defines a single aspect of an InsuranceProduct together
// with the statistical risk of the event happening, and the maximum payout
// in case the insured event happens.
concept InsurancePart {
    name: identifier;                       // internal name
    isApproved: boolean = false;            // indication of approval status
    statisticalRisk: PercentageLiteral;     // the statistical risk known for this event
    maximumPayOut: EuroLiteral;             // maximum payout in case the insured event happens
}

// Insurance/src/defs/editor-main-default.edit#L28-L35


InsurancePart{
[
    Insurance Part ${self.name}
        risk assessment: ${self.statisticalRisk}
        maximum payout: ${self.maximumPayOut}
        is approved: ${self.isApproved [YES | NO]}
]

Figure 1. Displaying different strings for boolean values

It is not necessary to always provide two textual representations for a boolean value. If only one string is added to the projection, its value is taken to represent true. The absence of the string represents false.

In the next example, the property isCompany will be shown as the keyword COMPANY. When the value of the property is true, the keyword is shown. When the value is false, the keyword is not shown.

// Insurance/src/defs/editor-main-default.edit#L67-L69


Entity {[
    ${self.isCompany [COMPANY]} ${self.name}

This example would be displayed as one of …

COMPANY entity PhilipsEnterPrises { // the value of isCompany is true
  ...
}
entity FritsPhilips { // the value of isCompany is false
  ...
}

Freon provides four native boolean controls: two types of switches, a checkbox, and a radio group. Each is indicated by adding a keyword to the property projection. The possible keywords are:

• switch, which shows a simple switch control,
• inner-switch, which shows a switch that holds text for the true and false values,
• checkbox, which shows an ordinary checkbox,
• radio, which shows a radio group with text for the true and false values,
• text, which indicates that the boolean value should be shown as text.

The latter is used to overwrite the global boolean projection, in case it demands one of the other options. Whenever text is shown, the strings to be used as true and false values can be indicated between square brackets, in the same way as the values for textual representations are given. When they are not present, the global definition is taken. If that is also not present then the default is true and false.

For the sake of the example, we have added a number of boolean properties to the concept BaseProduct.

// Insurance/src/defs/language-main.ast#L24-L39

concept BaseProduct {
    name: identifier;               // internal name
    isUnderConstruction: boolean;   // defines whether this base product is still 'raw'
    theme: InsuranceTheme;          // the 'kind' of insurance
    parts: InsurancePart[];         // all parts of this product
    // The following properties are present to show the different options for displaying booleans.
    isApprovedLevel1: boolean;
    isApprovedLevel2: boolean;
    isApprovedLevel3: boolean;
    yieldsProfit: boolean;
    range: number;
    nrOfUse: number;
    // The previoud two properties are present to show the different options for displaying numbers.
    // The following property is present to show the use of an external DatePicker component.
    date: string;
}

Each of the boolean properties is displayed differently.

// Insurance/src/defs/editor-main-controls.edit#L7-L11

is still under construction: ${self.isUnderConstruction switch}
is approved level1: ${self.isApprovedLevel1 radio [Sure | NoWay]}
is approved level2: ${self.isApprovedLevel2 inner-switch}
is approved level3: ${self.isApprovedLevel3 checkbox}
yields profit: ${self.yieldsProfit text [Plenty | Little]}

The result of this projection is shown in the screenshot below. Note that the text used for property self.isApprovedLevel2 is defined by the global boolean projection. See Global Projections.

Figure 2. Examples of different boolean controls

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