The simplest APIs are easy to use and suitable for CGIs where the program is restarted anew every time. However in situations where the script engine stays alive persistently, it is wasteful to reparse (and reallocate) the configuration every time. Consider following PHP snippet designed to be used with mod_php:
01 # Put this in the PHP initialization (it only needs to run once)
02 dl("php_zxid.so");
03 $conf = "PATH=/var/zxid/\&URL=https://sp1.zxidsp.org:8443/zxiddemo.php";
04 $cf = zxid_new_conf_to_cf($conf);
05 <? # For every page that is accessed
06 $qs = $_SERVER['REQUEST_METHOD'] == 'GET'
07 ? $_SERVER['QUERY_STRING']
08 : file_get_contents('php://input');
09 $res = zxid_simple_cf($cf, -1, $qs, null, 0x1800);
10 switch (substr($res, 0, 1)) {
11 case 'L': header($res); exit; # Redirect
12 case 'n': exit; # already handled
13 case 'b': my_send_metadata();
14 case 'e': my_render_login_screen();
15 case 'd': break; # Logged in case -- fall through
16 default: error_log("Unknown zxid_simple() res(%s)", res); exit;
17 }
18 # *** Parse the LDIF in $res into a hash of attributes (see zxidhlo.php)
19
20 ?>
21 <html><title>Protected content, logged in as <$=$attr['cn']$></title>
22 ...
23 </html>
24 <?
25 function my_render_login_screen()
26 {
27 ?>
28 <html><title>Please Login Using IdP</title>
29 ...
30 <?=zxid_idp_select_cf($cf, 0, 0x1800)?>
31 ...</html>
32 <? exit; }?>
Notes
Line 4 creates a system-wide configuration object that is later used by the other API calls
On line 9 we call zxid_simple_cf() with the created object. The second and third argument specify a buffer or string that contains the CGI form data to parse. This may come from QUERY_STRING of a GET request or from HTTP body of a POST request, as determined on line 8. The -1 means the length of the data should be determined using strlen(3), i.e. C string nul termination. The auto_flags == 0x1800 enables form tag wrapping and debug prints, but otherwise automation is disabled.
Since automation was disabled, we need to handle several cases of possible outcomes from zxid_simple_cf(), on lines 10-17.
From line 18 onwards we handle the login successful or already logged in case. First we split the LDIF entry into a hash so that we can access the attributes easily (e.g. cn on line 20).
On line 30 we call zxid_idp_list_cf() to create the form for choosing which IdP to use for login (remember that auto_flags == 0xc0 enabled the form wrapper). As can be seen the same configuration object, $cf, is used through out.