Text filter expression enables filtering features by matching feature annotations' with specified regular expression.

Feature Query dialog with Text Filter

Filter expression provides following controls and options:

• Comparer - specifies comparison operation for selected feature class.
• Text - lets you specify regular expression to match.
• Logical - specifies logical operator for filter expression within current filter.
• Picker button - enables specifying regular expression by letting you pick Text or MText entity in current drawing (available only on AutoCAD).

Regular expression or RegEx provides a concise and flexible means for "matching" (specifying and recognizing) strings of text, such as particular characters, words, or patterns of characters. A regular expression is written in a formal language interpreted by a built-in Holixa Infra Suite expression processor. It serves as a parser generator, positively identifying feature annotation (label) value that matches provided specification.  

Numeric Patterns

Pattern to match a string starting with numbers 0..99 (or 00..99):

\A[0-9]{1,2}.

Pattern to match a string starting with numbers 0..999 (or 000..999):

\A[0-9]{1,3}.

Character Patterns

Pattern to match a string starting with character '5':

^5.*

Pattern to match a string ending with character '5':

.*5$

Pattern to match a string starting and ending with character '5':

^5.*5$

String Patterns

Pattern to match a string containing case-insensitive substring 'TEST':

(?i).*TEST.*$

Other Patterns

Pattern to match a string having 1..25 letters in length:

^[a-zA-Z'.]{1,25}$

Pattern to match a string having 1..25 characters in length:

.{1,25}$

Pattern to match uppercase characters only:

^[A-Z0-9\s]*$

Pattern to find any lowercase characters inside a string:

(?-i)[a-z]

• (?-i) - means the search is case sensitive.
• (?i) - means the search is case insensitive.