Regular expressions

pattern(regex), pattern(regex, message) on string and text fields and itemPattern(regex, message) on stringList fields require the whole value to match.

ConfigField.string("id").pattern("[a-z0-9_-]{1,32}"),
ConfigField.string("webhook-url").label("Webhook URL").optional().writeOnly()
        .pattern("https://.+", "Use an https:// URL.")),
ConfigField.stringList("disabled-worlds")
        .itemPattern("[A-Za-z0-9_.-]{1,64}", "World names use letters, digits, '_', '-' and '.'."),

How a pattern matchesCopy Anchor Link

• Patterns use java.util.regex with default flags and Matcher.matches(): the whole value must match, so you need no ^ or $.
• With default flags \s and POSIX classes such as \p{Alpha} are ASCII only, and . matches one code point except line terminators.
• The message is shown on mismatch; the error code is pattern.

Checked while typing, or at reviewCopy Anchor Link

The editor repeats the check while typing only when the pattern has an exact JavaScript translation. Constructs without one are checked by the bridge only, when the owner reviews:

• inline flags,
• class intersections,
• possessive or atomic quantifiers,
• \Z, \G, \R.

Such patterns are accepted in schemas; the owner just learns about a mismatch one step later.

LimitsCopy Anchor Link