When filtering events by title or text, you can use regular expressions as your search text. This is optional, but quite powerful. Regular expressions give you the power to match all events, or a selection of events that are not exactly the same. Here are some rules for the syntax of regular expressions. You can find more information in many places. One good place to start is at Wikipedia. If you look at other documentation, you should know that FlexiCal's database system (MySQL) uses a type of regular expressions called "POSIX Extended Regular Expressions."
Here are some simple things to get you started.
Regular expressions reserve certain characters to represent something special. For the most part, if a character is not mentioned below, you can assume it only matches itself. If you run into trouble with that, try putting a backslash (\) in front of it.
.A period (.) will match anything but a null character, which is any character we want to use. If you want to search for a period, you have to put a backslash (\) in front of it, like this: ".".
[]To narrow the possible matches, you can use a collection. Put all the
characters you might want to match inside brackets ([]). To include a
closing bracket, put it immediately after the opening bracket. To match
any characters not in the collection, put a caret (^) immediately
after the opening bracket. You can also include a range of characters
(as determined by the character encoding in use, such as ASCII, Latin-1,
or UTF-8) within a collection by putting a hyphen (-) between two
characters, like this: [a-zA-Z0-9], which will include all lower- and
uppercase characters, as well as the digits 0-9. To include a literal
hyphen, put it at the beginning or end of the collection.
Putting an asterisk (*) behind a character or other item will cause
that item to match any number of that item, including zero. Using a
plus sign (+) will cause it to match one or more. To control exactly
how many repetitions you wish to match, put the range in brackets behind
the character or other item, like this: a{2,3}. That will match
either "aa" or "aaa". To include a literal asterisk, plus sign, or
curly bracket, precede it with a backslash (\).
You can make a single item out of a group of items by enclosing them in
parentheses, like this: (a repetitive phrase). This allows you to
match multiple repetitions of the enclosed item by putting the asterisk,
plus sign, or bracketed range after the closing parenthesis. You can
also include parenthesized items within other parenthesized items. To
match a literal parenthesis, put a backslash (\) in front of it.
One or more vertical pipe characters (|) inside a parenthesized group
separates the contents into a series of alternatives, any of which will
match for the entire parenthesized group. For example, the regular
expression A wise (decision|choice|option) will match any of the
following:
To include a literal vertical pipe character, precede it with a backslash (\).
A line ends with one or two special characters, depending upon the
operating system in use. For our purposes, it's a newline character,
represented by the sequence \n. A line begins either after the
previous line ends, or at the beginning of the text being searched.
If you wish to have your regular expression to match at the start of a line, precede it with a caret (^) character. To have it match at the end of a line, end it with a dollar sign ($). To make it match a whole line, do both. To include a literal caret or dollar sign, precede it with a backslash (\).