CONSTRUCTOR

    # Constructor - using a GET query string
    $qq = URI::Query->new($query_string);

    # Constructor - using an array of successive keys and values
    $qq = URI::Query->new(@params);

    # Constructor - using a hashref of key => value parameters,
    # where values are either scalars or arrayrefs of scalars
    $qq = URI::Query->new($cgi->Vars);

URI::Query also handles CGI.pm-style hashrefs, where multiple values are packed into a single string, separated by the "\0" (null) character.

All keys and values are URI unescaped at construction time, and are stored and referenced unescaped. So a query string like:

    group=prod%2Cinfra%2Ctest&op%3Aset=x%3Dy

is stored as:

    'group'     => 'prod,infra,test'
    'op:set'    => 'x=y'

You should always use the unescaped/normal variants in methods i.e.

     $qq->replace('op:set'  => 'x=z');

NOT:

     $qq->replace('op%3Aset'  => 'x%3Dz');

You can also construct a new URI::Query object by cloning an existing one:

     $qq2 = $qq->clone;

MODIFIER METHODS

    $qq->revert->strip('foo')->replace(bar => 123);

Note that URI::Query stashes a copy of the parameter set that existed at construction time, so that any changes made by these methods can be rolled back using 'revert()'. So you don't (usually) need to keep multiple copies around to handle incompatible changes.

revert()

Revert the current parameter set back to that originally given at construction time i.e. discard all changes made since construction.

strip($param1, $param2, ...)

Remove all occurrences of the given parameters and their values from the current parameter set.

strip_except($param1, $param2, ...)

Remove all parameters EXCEPT those given from the current parameter set.

strip_null()

Remove all parameters that have a value of undef from the current parameter set.

replace($param1 => $value1, $param2, $value2, ...)

Replace the values of the given parameters in the current parameter set with these new ones. Parameter names must be scalars, but values can be either scalars or arrayrefs of scalars, when multiple values are desired.

Note that 'replace' can also be used to add or append, since there's no requirement that the parameters already exist in the current parameter set.

strip_like($regex)

Remove all parameters whose names match the given (qr-quoted) regex e.g.

    $qq->strip_like(qr/^utm/)
    

Does NOT match against parameter values.

separator($separator)

Set the argument separator to use for output. Default: '&'.

ACCESSOR METHODS

has_changed()

If the query is actually changed by any of the modifier methods (strip, strip_except, strip_null, strip_like, or replace) it sets an internal changed flag which can be access by:

    $qq->has_changed
    

revert() resets the has_changed flag to false.

OUTPUT METHODS

"$qq", stringify(), stringify($separator)

Return the current parameter set as a conventional param=value query string, using $separator as the separator if given. e.g.

    foo=1&bar=2&bar=3
    

Note that all parameters and values are URI escaped by stringify(), so that query-string reserved characters do not occur within elements. For instance, a parameter set of:

    'group'     => 'prod,infra,test'
    'op:set'    => 'x=y'
    

will be stringified as:

    group=prod%2Cinfra%2Ctest&op%3Aset=x%3Dy
    

qstringify(), qstringify($separator)

Convenience method to stringify with a leading '?' e.g.

    ?foo=1&bar=2&bar=3
    

hash()

Return a hash (in list context) or hashref (in scalar context) of the current parameter set. Single-item parameters have scalar values, while while multiple-item parameters have arrayref values e.g.

    {
        foo => 1,
        bar => [ 2, 3 ],
    }
    

hash_arrayref()

Return a hash (in list context) or hashref (in scalar context) of the current parameter set. All values are returned as arrayrefs, including those with single values e.g.

    {
        foo => [ 1 ],
        bar => [ 2, 3 ],
    }
    

hidden()

Returns the current parameter set as a concatenated string of hidden input tags, one per parameter-value e.g.

    <input type="hidden" name="foo" value="1" />
    <input type="hidden" name="bar" value="2" />
    <input type="hidden" name="bar" value="3" />