Package =TWiki::Attrs

Class of attribute sets, designed for parsing and storing attribute values from a TWiki tag e.g. %TAG{"joe" fred="bad" joe="mad"}%

An attribute set is a hash containing an entry for each parameter. The default parameter (unnamed quoted string) is named _DEFAULT in the hash.

Attributes declared later in the string will override those of the same name defined earlier. The one exception to this is the _DEFAULT key, where the first instance is always taken.

As well as the default TWiki syntax (parameter values double-quoted) this class also parses single-quoted values, unquoted spaceless values, spaces around the =, and commas as well as spaces separating values. The extended syntax has to be enabled by passing the $friendly parameter to new.

On this page:

ClassMethod new ($string,$friendly)=>\%attrsObjectRef
ObjectMethod isEmpty () -> boolean
ObjectMethod remove ($key) -> $value
ObjectMethod stringify () -> $string

ClassMethod new `($string,$friendly)=>\%attrsObjectRef`

$string - String containing attribute specification
$friendly - if true, the parse will be according to the extended syntax pioneered by the original Contrib::Attrs. Otherwise it will be strict as per traditional TWiki syntax.

Parse a standard attribute string containing name=value pairs and create a new attributes object. The value may be a word or a quoted string. If there is an error during parsing, the parse will complete but $attrs->{_ERROR} will be set in the new object. $attrs->{_RAW} will always contain the full unprocessed $string.

Extended syntax example:

my $attrs = new TWiki::Attrs('the="time \\"has come", "the walrus" said to=speak of=\'many \\'things\', 1);

In this example:

the will be time "has come
__default__ will be the walrus
said will be on
to will be speak
of will be many 'things

Only " and ' are escaped.

Traditional syntax is as old TWiki, except that the whole string is parsed (the old parser would only recognise default values in position 1, nowhere else)