Installer - Screens and Actions Groups

## Installer - Screens and Actions Groups |

| Screen and action groups can be configured on the screens & and actions tab.

| Actions and screens can be grouped in the tree of installer elements. Groups of the same type can be nested, meaning that you can put a screen group into a screen group or an action group into an action group. You can nest as many levels of groups as you wish. Next to the label of the screen or action group in the tree of installer elements, the number of all contained screens or actions is shown in bold font. Elements in nested groups are counted as well.

| Grouping offers the following: Organization If you have many screens or actions, groups emphasize which elements belong together. You can add a common comment to the group. Common condition Groups have a "Condition expression" property that allows you to skip the group with a common condition instead of having to repeat the condition for each contained element. Single link target If you want to reuse a set of adjacent screens or actions in a different part of your project, you can put them in a group and add a single link to that group instead of linking to each element separately. Looping A group has a "Loop expression" property that allows you to execute the group repeatedly until the loop expression returns `false`. Jump targets (screen groups only) When you jump to a screen programmatically (with `context.gotoScreen(...)`), it is more maintainable to jump to a group instead of to a single screen. You can think of the group as taking the function of a label in this case.

| The configurable properties of screen and action groups are:
Screen group
A screen group contains multiple screens that can be disabled with a single condition expression on the group.
Properties:
Condition expression [Control Flow] This expression is evaluated just before the screen is displayed. If the expression or script returns `false`, the entire screen group will be skipped. Loop expression [Control Flow] This expression is evaluated when the end of the screen group is reached. If it returns `true`, all screens will be repeated.
Action group
An action group contains multiple actions that can be disabled with a single condition expression on the group.
Properties:
Condition expression [Control Flow] This expression is evaluated just before the action is executed. If the expression or script returns `false`, the entire action group will be skipped. Loop expression [Control Flow] This expression is evaluated when the end of the action group is reached. If it returns `true`, all actions will be repeated. On error break group [Error Handling] If selected, and one of the contained actions returns with an error, the control flow will step out of the action group and continue with the next element after the group. This behavior only takes effect if the problematic action has its failure strategy set to "Continue on failure". Default error message [Error Handling] A default error message used by all actions that have no dedicated error message.