Filtering rules

LF‑ET also allows filtering of rules ac­cor­ding to complex criteria.

An example

Only those rules should be shown that belong to rule group 4 or that lead to this:

filter 01

The keyboard shortcut ALT+F or the context menu “Show rules > Filter rules”…​

filter 02

…​are used to open a dialog in which one or more filtering instructions for rules are specified and can be exe­cu­ted:

filter 03

Filtering instructions

  • A filtering instruction consists of:

    1. An identifier of a condition or action (e.g. C01)
      or the keyword RID for rule-ID if filtering ac­cor­ding to rule-IDs is to be run.

    2. An equal or unequal operator (=, ==, !=) and

    3. One or more condition or action values

  • The values entered must in each case correspond to one of the symbols of the relevant condition or action, including the irrelevance indicator, i.e. the minus sign.

  • Several values are separated with a blank, a comma or a semicolon.

  • They are case-insensitive.

  • If values contain blanks or other special characters, they must be closed in single or double inverted commas.

Wildcards and regular expressions

  • If values are entered, the following wildcards can be used:

    ? - precisely one unspecified character
    * - any number of unspecified characters

Regular expressions are also possible, however, they must only start with ^ and end with $

  • Value entries with wildcards or regular expressions must not be placed in inverted commas.

Linking and grouping of filtering instructions

  • Several such filtering instructions can in turn be linked with AND, NOT, OR or XOR.

  • Some normal language synonyms such as AND, AND NOT, BUT NOT, OR etc. are also possible

  • They are case-insensitive.

  • Apart from that, an additional grouping with brackets is possible:

    • in order to improve legibility or

    • when standard prioritizing (e.g. AND stronger than OR) should be overridden

Comments

  • Comments begin with // or /*

  • All characters that follow apply to the relevant end of line as a comment and are ignored.

Other

  • Blanks and line breaks between instructions and instruction elements are ignored.

  • If there are errors, e.g. invalid value entries, detailed information is displayed directly in the information section of the dialog.

  • LF‑ET “remembers” the specified filtering instructions individually for each decision table until LF‑ET is closed.

Saving

  • Successful filtering can be permanently saved as a snapshot by clicking “Save”.

Further information