File Coverage

=head1 NAME

C4::Letters - Give functions for Letters management

=head1 SYNOPSIS

  use C4::Letters;

=head1 DESCRIPTION

  "Letters" is the tool used in Koha to manage informations sent to the patrons and/or the library. This include some cron jobs like
  late issues, as well as other tasks like sending a mail to users that have subscribed to a "serial issue alert" (= being warned every time a new issue has arrived at the library)

  Letters are managed through "alerts" sent by Koha on some events. All "alert" related functions are in this module too.

=head2 GetLetters([$category])

  $letters = &GetLetters($category);
  returns informations about letters.
  if needed, $category filters for letters given category
  Create a letter selector with the following code

=head3 in PERL SCRIPT

my $letters = GetLetters($cat);
my @letterloop;
foreach my $thisletter (keys %$letters) {
    my $selected = 1 if $thisletter eq $letter;
    my %row =(
        value => $thisletter,
        selected => $selected,
        lettername => $letters->{$thisletter},
    );
    push @letterloop, \%row;
}
$template->param(LETTERLOOP => \@letterloop);

=head3 in TEMPLATE

    <select name="letter">
        <option value="">Default</option>
    <!-- TMPL_LOOP name="LETTERLOOP" -->
        <option value="<!-- TMPL_VAR name="value" -->" <!-- TMPL_IF name="selected" -->selected<!-- /TMPL_IF -->><!-- TMPL_VAR name="lettername" --></option>
    <!-- /TMPL_LOOP -->
    </select>

=cut

=head2 addalert ($borrowernumber, $type, $externalid)

    parameters : 
    - $borrowernumber : the number of the borrower subscribing to the alert
    - $type : the type of alert.
    - $externalid : the primary key of the object to put alert on. For issues, the alert is made on subscriptionid.
    
    create an alert and return the alertid (primary key)

=cut

=head2 delalert ($alertid)

    parameters :
    - alertid : the alert id
    deletes the alert

=cut

=head2 getalert ([$borrowernumber], [$type], [$externalid])

    parameters :
    - $borrowernumber : the number of the borrower subscribing to the alert
    - $type : the type of alert.
    - $externalid : the primary key of the object to put alert on. For issues, the alert is made on subscriptionid.
    all parameters NON mandatory. If a parameter is omitted, the query is done without the corresponding parameter. For example, without $externalid, returns all alerts for a borrower on a topic.

=cut

=head2 findrelatedto($type, $externalid)

	parameters :
	- $type : the type of alert
	- $externalid : the id of the "object" to query
	
	In the table alert, a "id" is stored in the externalid field. This "id" is related to another table, depending on the type of the alert.
	When type=issue, the id is related to a subscriptionid and this sub returns the name of the biblio.

=cut

=head2 SendAlerts

    parameters :
    - $type : the type of alert
    - $externalid : the id of the "object" to query
    - $letter : the letter to send.

    send an alert to all borrowers having put an alert on a given subject.

=cut

=head2 parseletter($letter, $table, $pk)

    parameters :
    - $letter : a hash to letter fields (title & content useful)
    - $table : the Koha table to parse.
    - $pk : the primary key to query on the $table table
    parse all fields from a table, and replace values in title & content with the appropriate value
    (not exported sub, used only internally)

=cut

=head2 EnqueueLetter

  my $success = EnqueueLetter( { letter => $letter, 
        borrowernumber => '12', message_transport_type => 'email' } )

places a letter in the message_queue database table, which will
eventually get processed (sent) by the process_message_queue.pl
cronjob when it calls SendQueuedMessages.

return true on success

=cut

=head2 SendQueuedMessages ([$hashref]) 

  my $sent = SendQueuedMessages( { verbose => 1 } );

sends all of the 'pending' items in the message queue.

returns number of messages sent.

=cut

=head2 GetRSSMessages

  my $message_list = GetRSSMessages( { limit => 10, borrowernumber => '14' } )

returns a listref of all queued RSS messages for a particular person.

=cut

=head2 GetPrintMessages

  my $message_list = GetPrintMessages( { borrowernumber => $borrowernumber } )

Returns a arrayref of all queued print messages (optionally, for a particular
person).

=cut

=head2 GetQueuedMessages ([$hashref])

  my $messages = GetQueuedMessage( { borrowernumber => '123', limit => 20 } );

fetches messages out of the message queue.

returns:
list of hashes, each has represents a message in the message queue.

=cut

=head2 _add_attachements

named parameters:
letter - the standard letter hashref
attachments - listref of attachments. each attachment is a hashref of:
  type - the mime type, like 'text/plain'
  content - the actual attachment
  filename - the name of the attachment.
message - a MIME::Lite object to attach these to.

returns your letter object, with the content updated.

=cut