<?php

/**

* SIP2 Class

*

* This class provides a methoid of communicating with an Integrated

* Library System using 3M's SIP2 standard.

*

* PHP version 5

*

*

* @package

* @author     John Wohlers <john@wohlershome.net>

* @licence    http://opensource.org/licenses/gpl-3.0.html

* @copyright  John Wohlers <john@wohlershome.net>

* @version    $Id$

* @link       http://php-sip2.googlecode.com/

*/

/**

*  2008.04.11

*  Encorported a bug fix submitted by Bob Wicksall

*

*  TODO

*   - Clean up variable names, check for consistancy

*   - Add better i18n support, including functions to handle the SIP2 language definitions

*

*/

/**

* General Usage:

*    include('sip2.class.php');

*

*    // create object

*    $mysip = new sip2;

*

*    // Set host name

*    $mysip->hostname = 'server.example.com';

*    $mysip->port = 6002;

*

*    // Identify a patron

*    $mysip->patron = '101010101';

*    $mysip->patronpwd = '010101';

*

*    // connect to SIP server

*    $result = $mysip->connect();

*

*    // selfcheck status mesage goes here...

*

*

*    // Get Charged Items Raw response

*    $in = $mysip->msgPatronInformation('charged');

*

*    // parse the raw response into an array

*    $result = $mysip->parsePatronInfoResponse( $mysip->get_message($in) );

*

*/

class sip2 {

/* Public variables for configuration */

public $hostname;

public $port         = 6002; /* default sip2 port for Sirsi */

public $library      = '';

public $language     = '001'; /* 001= english */

/* Patron ID */

public $patron       = ''; /* AA */

public $patronpwd    = ''; /* AD */

 


/*terminal password */

public $AC           = ''; /*AC */

 


/* Maximum number of resends allowed before get_message gives up */

public $maxretry     = 3;

 


/* Terminator s */

public $fldTerminator = '|';

public $msgTerminator = "\r\n";

 


/* Login Variables */

public $UIDalgorithm = 0;   /* 0    = unencrypted, default */

public $PWDalgorithm = 0;   /* undefined in documentation */

public $scLocation   = '';  /* Location Code */

/* Debug */

public $debug        = false;

 


/* Private variables for building messages */

public $AO = 'WohlersSIP';

public $AN = 'SIPCHK';

 


/* Private variable to hold socket connection */

private $socket;

 


/* Sequence number counter */

private $seq   = -1;

/* resend counter */

private $retry = 0;

 


/* Workarea for building a message */

private $msgBuild = '';

private $noFixed = false;

 


function msgPatronStatusRequest() {

/* Server Response: Patron Status Response message. */

$this->_newMessage('23');

$this->_addFixedOption($this->language, 3);

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AC',$this->AC);

$this->_addVarOption('AD',$this->patronpwd);

return $this->_returnMessage();

}

 


function msgCheckout($item, $nbDateDue ='', $scRenewal='N', $itmProp ='', $fee='N', $noBlock='N', $cancel='N') {

/* Checkout an item  (11) - untested */

$this->_newMessage('11');

$this->_addFixedOption($scRenewal, 1);

$this->_addFixedOption($noBlock, 1);

$this->_addFixedOption($this->_datestamp(), 18);

if ($nbDateDue != '') {

/* override defualt date due */

$this->_addFixedOption($this->_datestamp($nbDateDue), 18);

} else {

/* send a blank date due to allow ACS to use default date due computed for item */

$this->_addFixedOption('', 18);

}

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AB',$item);

$this->_addVarOption('AC',$this->AC);

$this->_addVarOption('CH',$itmProp, true);

$this->_addVarOption('AD',$this->patronpwd, true);

$this->_addVarOption('BO',$fee, true); /* Y or N */

$this->_addVarOption('BI',$cancel, true); /* Y or N */

 


return $this->_returnMessage();

}

 


function msgCheckin($item, $itmReturnDate, $itmLocation = '', $itmProp = '', $noBlock='N', $cancel = '') {

/* Checkin an item (09) - untested */

if ($itmLocation == '') {

/* If no location is specified, assume the defualt location of the SC, behavior suggested by spec*/

$itmLocation = $this->scLocation;

}

$this->_newMessage('09');

$this->_addFixedOption($noBlock, 1);

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addFixedOption($this->_datestamp($itmReturnDate), 18);

$this->_addVarOption('AP',$itmLocation);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AB',$item);

$this->_addVarOption('AC',$this->AC);

$this->_addVarOption('CH',$itmProp, true);

$this->_addVarOption('BI',$cancel, true); /* Y or N */

 


return $this->_returnMessage();

}

function msgBlockPatron($message, $retained='N') {

/* Blocks a patron, and responds with a patron status response  (01) - untested */

$this->_newMessage('01');

$this->_addFixedOption($retained, 1); /* Y if card has been retained */

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AL',$message);

$this->_addVarOption('AA',$this->AA);

$this->_addVarOption('AC',$this->AC);

 


return $this->_returnMessage();

}

 


function msgSCStatus($status = 0, $width = 80, $version = 2) {

/* selfcheck status message, this should be sent immediatly after login  - untested */

/* status codes, from the spec:

* 0 SC unit is OK

* 1 SC printer is out of paper

* 2 SC is about to shut down

*/

if ($version > 3) {

$version = 2;

}

if ($status < 0 || $status > 2) {

$this->_debugmsg( "SIP2: Invalid status passed to msgSCStatus" );

return false;

}

$this->_newMessage('99');

$this->_addFixedOption($status, 1);

$this->_addFixedOption($width, 3);

$this->_addFixedOption(sprintf("%03.2f",$version), 4);

return $this->_returnMessage();

}

function msgRequestACSResend () {

/* Used to request a resend due to CRC mismatch - No sequence number is used */

$this->_newMessage('97');

return $this->_returnMessage(false);

}

function msgLogin($sipLogin, $sipPassword) {

/* Login (93) - untested */

$this->_newMessage('93');

$this->_addFixedOption($this->UIDalgorithm, 1);

$this->_addFixedOption($this->PWDalgorithm, 1);

$this->_addVarOption('CN',$sipLogin);

$this->_addVarOption('CO',$sipPassword);

$this->_addVarOption('CP',$this->scLocation, true);

return $this->_returnMessage();

}

function msgPatronInformation($type, $start = '1', $end = '5') {

/*

* According to the specification:

* Only one category of items should be  requested at a time, i.e. it would take 6 of these messages,

* each with a different position set to Y, to get all the detailed information about a patron's items.

*/

$summary['none']     = '      ';

$summary['hold']     = 'Y     ';

$summary['overdue']  = ' Y    ';

$summary['charged']  = '  Y   ';

$summary['fine']     = '   Y  ';

$summary['recall']   = '    Y ';

$summary['unavail']  = '     Y';

 


/* Request patron information */

$this->_newMessage('63');

$this->_addFixedOption($this->language, 3);

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addFixedOption(sprintf("%-10s",$summary[$type]), 10);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('AD',$this->patronpwd, true);

$this->_addVarOption('BP',$start, true); /* old function version used padded 5 digits, not sure why */

$this->_addVarOption('BQ',$end, true); /* old function version used padded 5 digits, not sure why */

return $this->_returnMessage();

}

function msgEndPatronSession() {

/*  End Patron Session, should be sent before switching to a new patron. (35) - untested */

$this->_newMessage('35');

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('AD',$this->patronpwd, true);

return $this->_returnMessage();

}

 


/* Fee paid function should go here */

function msgFeePaid ($feeType, $pmtType, $pmtAmount, $curType = 'USD', $feeId = '', $transId = '') {

/* Fee payment function (37) - untested */

/* Fee Types: */

/* 01 other/unknown */

/* 02 administrative */

/* 03 damage */

/* 04 overdue */

/* 05 processing */

/* 06 rental*/

/* 07 replacement */

/* 08 computer access charge */

/* 09 hold fee */

/* Value Payment Type */

/* 00   cash */

/* 01   VISA */

/* 02   credit card */

 


if (!is_numeric($feeType) || $feeType > 99 || $feeType < 1) {

/* not a valid fee type - exit */

$this->_debugmsg( "SIP2: (msgFeePaid) Invalid fee type: {$feeType}");

return false;

}

if (!is_numeric($pmtType) || $pmtType > 99 || $pmtType < 0) {

/* not a valid payment type - exit */

$this->_debugmsg( "SIP2: (msgFeePaid) Invalid payment type: {$pmtType}");

return false;

}

 


$this->_newMessage('37');

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addFixedOption(sprintf('%02d', $feeType), 2);

$this->_addFixedOption(sprintf('%02d', $pmtType), 2);

$this->_addFixedOption($curType, 3);

$this->_addVarOption('BV',$pmtAmount); /* due to currancy format localization, it is up to the programmer to properly format their payment amount */

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('AD',$this->patronpwd, true);

$this->_addVarOption('CG',$feeId, true);

$this->_addVarOption('BK',$transId, true);

 


return $this->_returnMessage();

}

 


function msgItemInformation($item) {

$this->_newMessage('17');

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AB',$item);

$this->_addVarOption('AC',$this->AC, true);

return $this->_returnMessage();

 


}

function msgItemStatus ($item, $itmProp = '') {

/* Item status update function (19) - untested  */

$this->_newMessage('19');

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AB',$item);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('CH',$itmProp);

return $this->_returnMessage();

}

 


function msgPatronEnable () {

/* Patron Enable function (25) - untested */

/*  This message can be used by the SC to re-enable canceled patrons. It should only be used for system testing and validation. */

$this->_newMessage('25');

$this->_addFixedOption($this->_datestamp(), 18);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('AD',$this->patronpwd, true);

return $this->_returnMessage();

}

 


function msgHold($mode, $expDate = '', $holdtype = '', $item = '', $title = '', $fee='N', $pkupLocation = '') {

/* mode validity check */

/*

* - remove hold

* + place hold

* * modify hold

*/

if (strpos('-+*',$mode) === false) {

/* not a valid mode - exit */

$this->_debugmsg( "SIP2: Invalid hold mode: {$mode}");

return false;

}

 


if ($holdtype != '' && ($holdtype < 1 || $holdtype > 9)) {

/*

* Valid hold types range from 1 - 9

* 1   other

* 2   any copy of title

* 3   specific copy

* 4   any copy at a single branch or location

*/

$this->_debugmsg( "SIP2: Invalid hold type code: {$holdtype}");

return false;

}

$this->_newMessage('15');

$this->_addFixedOption($mode, 1);

$this->_addFixedOption($this->_datestamp(), 18);

if ($expDate != '') {

/* hold expiration date,  due to the use of the datestamp function, we have to check here for empty value. when datestamp is passed an empty value it will generate a current datestamp */

$this->_addVarOption('BW', $this->_datestamp($expDate), true); /*spec says this is fixed field, but it behaves like a var field and is optional... */

}

$this->_addVarOption('BS',$pkupLocation, true);

$this->_addVarOption('BY',$holdtype, true);

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AD',$this->patronpwd, true);

$this->_addVarOption('AB',$item, true);

$this->_addVarOption('AJ',$title, true);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('BO',$fee, true); /* Y when user has agreed to a fee notice */

 


return $this->_returnMessage();

}

function msgRenew($item = '', $title = '', $nbDueDate = '', $itmProp = '', $fee= 'N', $noBlock = 'N', $thirdParty = 'N') {

/* renew a single item (29) - untested */

$this->_newMessage('29');

$this->_addFixedOption($thirdParty, 1);

$this->_addFixedOption($noBlock, 1);

$this->_addFixedOption($this->_datestamp(), 18);

if ($nbDateDue != '') {

/* override defualt date due */

$this->_addFixedOption($this->_datestamp($nbDateDue), 18);

} else {

/* send a blank date due to allow ACS to use default date due computed for item */

$this->_addFixedOption('', 18);

}

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AD',$this->patronpwd, true);

$this->_addVarOption('AB',$item, true);

$this->_addVarOption('AJ',$title, true);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('CH',$itmProp, true);

$this->_addVarOption('BO',$fee, true); /* Y or N */

 


return $this->_returnMessage();

}

function msgRenewAll($fee = 'N') {

/* renew all items for a patron (65) - untested */

$this->_newMessage('65');

$this->_addVarOption('AO',$this->AO);

$this->_addVarOption('AA',$this->patron);

$this->_addVarOption('AD',$this->patronpwd, true);

$this->_addVarOption('AC',$this->AC, true);

$this->_addVarOption('BO',$fee, true); /* Y or N */

return $this->_returnMessage();

}

 


function parsePatronStatusResponse($response) {

$result['fixed'] =

array(

'PatronStatus'      => substr($response, 2, 14),

'Language'          => substr($response, 16, 3),

'TransactionDate'   => substr($response, 19, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 37);

return $result;

}

function parseCheckoutResponse($response) {

$result['fixed'] =

array(

'Ok'                => substr($response,2,1),

'RenewalOk'         => substr($response,3,1),

'Magnetic'          => substr($response,4,1),

'Desensitize'       => substr($response,5,1),

'TransactionDate'   => substr($response,6,18),

);

 


$result['variable'] = $this->_parsevariabledata($response, 24);

return $result;

}

function parseCheckinResponse($response) {

$result['fixed'] =

array(

'Ok'                => substr($response,2,1),

'Resensitize'       => substr($response,3,1),

'Magnetic'          => substr($response,4,1),

'Alert'             => substr($response,5,1),

'TransactionDate'   => substr($response,6,18),

);

 


$result['variable'] = $this->_parsevariabledata($response, 24);

return $result;

}

function parseACSStatusResponse($response) {

$result['fixed'] =

array(

'Online'            => substr($response, 2, 1),

'Checkin'           => substr($response, 3, 1),  /* is Checkin by the SC allowed ?*/

'Checkout'          => substr($response, 4, 1),  /* is Checkout by the SC allowed ?*/

'Renewal'                       => substr($response, 5, 1),  /* renewal allowed? */

'PatronUpdate'      => substr($response, 6, 1),  /* is patron status updating by the SC allowed ? (status update ok)*/

'Offline'           => substr($response, 7, 1),

'Timeout'           => substr($response, 8, 3),

'Retries'           => substr($response, 11, 3),

'TransactionDate'   => substr($response, 14, 18),

'Protocol'          => substr($response, 32, 4),

);

 


$result['variable'] = $this->_parsevariabledata($response, 36);

return $result;

}

function parseLoginResponse($response) {

$result['fixed'] =

array(

'Ok'                => substr($response, 2, 1),

);

$result['variable'] = array();

return $result;

}

function parsePatronInfoResponse($response) {

 


$result['fixed'] =

array(

'PatronStatus'      => substr($response, 2, 14),

'Language'          => substr($response, 16, 3),

'TransactionDate'   => substr($response, 19, 18),

'HoldCount'         => intval (substr($response, 37, 4)),

'OverdueCount'      => intval (substr($response, 41, 4)),

'ChargedCount'      => intval (substr($response, 45, 4)),

'FineCount'         => intval (substr($response, 49, 4)),

'RecallCount'       => intval (substr($response, 53, 4)),

'UnavailableCount'  => intval (substr($response, 57, 4))

);

$result['variable'] = $this->_parsevariabledata($response, 61);

return $result;

}

function parseEndSessionResponse($response) {

/*   Response example:  36Y20080228 145537AOWOHLERS|AAX00000000|AY9AZF474   */

 


$result['fixed'] =

array(

'EndSession'        => substr($response, 2, 1),

'TransactionDate'   => substr($response, 3, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 21);

 


return $result;

}

 


function parseFeePaidResponse($response) {

$result['fixed'] =

array(

'PaymentAccepted'   => substr($response, 2, 1),

'TransactionDate'   => substr($response, 3, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 21);

return $result;

 


}

function parseItemInfoResponse($response) {

$result['fixed'] =

array(

'CirculationStatus' => intval (substr($response, 2, 2)),

'SecurityMarker'    => intval (substr($response, 4, 2)),

'FeeType'           => intval (substr($response, 6, 2)),

'TransactionDate'   => substr($response, 8, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 26);

return $result;

}

function parseItemStatusResponse($response) {

$result['fixed'] =

array(

'PropertiesOk'      => substr($response, 2, 1),

'TransactionDate'   => substr($response, 3, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 21);

return $result;

 


}

function parsePatronEnableResponse($response) {

$result['fixed'] =

array(

'PatronStatus'      => substr($response, 2, 14),

'Language'          => substr($response, 16, 3),

'TransactionDate'   => substr($response, 19, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 37);

return $result;

 


}

function parseHoldResponse($response) {

$result['fixed'] =

array(

'Ok'                => substr($response, 2, 1),

'available'         => substr($response, 3, 1),

'TransactionDate'   => substr($response, 4, 18),

'ExpirationDate'    => substr($response, 22, 18)

);

$result['variable'] = $this->_parsevariabledata($response, 40);

return $result;

}

 


 


function parseRenewResponse($response) {

/* Response Example:  300NUU20080228    222232AOWOHLERS|AAX00000241|ABM02400028262|AJFolksongs of Britain and Ireland|AH5/23/2008,23:59|CH|AFOverride required to exceed renewal limit.|AY1AZCDA5 */

$result['fixed'] =

array(

'Ok'                => substr($response, 2, 1),

'RenewalOk'         => substr($response, 3, 1),

'Magnetic'          => substr($response, 4, 1),

'Desensitize'       => substr($response, 5, 1),

'TransactionDate'   => substr($response, 6, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 24);

return $result;

}

 


function parseRenewAllResponse($response) {

$result['fixed'] =

array(

'Ok'                => substr($response, 2, 1),

'Renewed'           => substr($response, 3, 4),

'Unrenewed'         => substr($response, 7, 4),

'TransactionDate'   => substr($response, 11, 18),

);

$result['variable'] = $this->_parsevariabledata($response, 29);

return $result;

}

 


 


function get_message ($message) {

/* sends the current message, and gets the response */

$result     = '';

$terminator = '';

 


$this->_debugmsg('SIP2: Sending SIP2 request...');

socket_write($this->socket, $message, strlen($message));

$this->_debugmsg('SIP2: Request Sent, Reading response');

while ($terminator != "\x0D") {

$nr = socket_recv($this->socket,$terminator,1,0);

$result = $result . $terminator;

}

$this->_debugmsg("SIP2: {$result}");

/* test message for CRC validity */

if ($this->_check_crc($result)) {

/* reset the retry counter on successful send */

$this->retry=0;

$this->_debugmsg("SIP2: Message from ACS passed CRC check");

} else {

/* CRC check failed, request a resend */

$this->retry++;

if ($this->retry < $this->maxretry) {

/* try again */

$this->_debugmsg("SIP2: Message failed CRC check, retrying ({$this->retry})");

 


$this->get_message($message);

} else {

/* give up */

$this->_debugmsg("SIP2: Failed to get valid CRC after {$this->maxretry} retries.");

return false;

}

}

return $result;

}

function connect() {

/* Socket Communications  */

$this->_debugmsg( "SIP2: --- BEGIN SIP communication ---");

 


/* Get the IP address for the target host. */

$address = gethostbyname($this->hostname);

/* Create a TCP/IP socket. */

$this->socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

/* check for actual truly false result using ===*/

if ($this->socket === false) {

$this->_debugmsg( "SIP2: socket_create() failed: reason: " . socket_strerror($this->socket));

return false;

} else {

$this->_debugmsg( "SIP2: Socket Created" );

}

$this->_debugmsg( "SIP2: Attempting to connect to '$address' on port '{$this->port}'...");

/* open a connection to the host */

$result = socket_connect($this->socket, $address, $this->port);

if (!$result) {

$this->_debugmsg("SIP2: socket_connect() failed.\nReason: ($result) " . socket_strerror($result));

} else {

$this->_debugmsg( "SIP2: --- SOCKET READY ---" );

}

/* return the result from the socket connect */

return $result;

 


}

 


function disconnect () {

/*  Close the socket */

socket_close($this->socket);

}

/* Core local utility functions */

function _datestamp($timestamp = '') {

/* generate a SIP2 compatable datestamp */

/* From the spec:

* YYYYMMDDZZZZHHMMSS.

* All dates and times are expressed according to the ANSI standard X3.30 for date and X3.43 for time.

* The ZZZZ field should contain blanks (code $20) to represent local time. To represent universal time,

*  a Z character(code $5A) should be put in the last (right hand) position of the ZZZZ field.

* To represent other time zones the appropriate character should be used; a Q character (code $51)

* should be put in the last (right hand) position of the ZZZZ field to represent Atlantic Standard Time.

* When possible local time is the preferred format.

*/

if ($timestamp != '') {

/* Generate a proper date time from the date provided */

return date('Ymd    His', $timestamp);

} else {

/* Current Date/Time */

return date('Ymd    His');

}

}

function _parsevariabledata($response, $start) {

$result = array();

$result['Raw'] = explode("|", substr($response,$start,-7));

foreach ($result['Raw'] as $item) {

$field = substr($item,0,2);

$value = substr($item,2);

/* SD returns some odd values on ocassion, Unable to locate the purpose in spec, so I strip from

* the parsed array. Orig values will remain in ['raw'] element

*/

$clean = trim($value, "\x00..\x1F");

if (trim($clean) <> '') {

$result[$field][] = $clean;

}

}

$result['AZ'][] = substr($response,-5);

return ($result);

}

function _crc($buf) {

/* Calculate CRC  */

$sum = 0;

$len = strlen($buf);

for ($n = 0; $n < $len; $n++) {

$sum = $sum + ord(substr($buf, $n, 1));

}

$crc = ($sum & 0xFFFF) * -1;

/* 2008.03.15 - Fixed a bug that allowed the checksum to be larger then 4 digits */

return substr(sprintf ("%4X", $crc), -4, 4);

} /* end crc */

function _getseqnum() {

/* Get a sequence number for the AY field */

/* valid numbers range 0-9 */

$this->seq++;

if ($this->seq > 9 ) {

$this->seq = 0;

}

return ($this->seq);

}

 


function _debugmsg($message) {

/* custom debug function,  why repeat the check for the debug flag in code... */

if ($this->debug) {

trigger_error( $message, E_USER_NOTICE);

}

}

 


function _check_crc($message) {

/* test the recieved message's CRC by generating our own CRC from the message */

$test = preg_split('/(.{4})$/',trim($message),2,PREG_SPLIT_DELIM_CAPTURE);

if ($this->_crc($test[0]) == $test[1]) {

return true;

} else {

return false;

}

}

 


function _newMessage($code) {

/* resets the msgBuild variable to the value of $code, and clears the flag for fixed messages */

$this->noFixed  = false;

$this->msgBuild = $code;

}

 


function _addFixedOption($value, $len) {

/* adds afixed length option to the msgBuild IF no variable options have been added. */

if ( $this->noFixed ) {

return false;

} else {

$this->msgBuild .= sprintf("%{$len}s", substr($value,0,$len));

return true;

}

}

 


function _addVarOption($field, $value, $optional = false) {

/* adds a varaiable length option to the message, and also prevents adding addtional fixed fields */

if ($optional == true && $value == '') {

/* skipped */

$this->_debugmsg( "SIP2: Skipping optional field {$field}");

} else {

$this->noFixed  = true; /* no more fixed for this message */

$this->msgBuild .= $field . substr($value, 0, 255) . $this->fldTerminator;

}

return true;

}

 


function _returnMessage($withSeq = true, $withCrc = true) {

/* Finalizes the message and returns it.  Message will remain in msgBuild until newMessage is called */

if ($withSeq) {

$this->msgBuild .= 'AY' . $this->_getseqnum();

}

if ($withCrc) {

$this->msgBuild .= 'AZ';

$this->msgBuild .= $this->_crc($this->msgBuild);

}

$this->msgBuild .= $this->msgTerminator;

return $this->msgBuild;

}

 


}

?>