<div dir="ltr">You don't.  If you look at the beforesave calls [1] or dig a little deeper into the VTEventTrigger.trigger [2], you'll see that an exception is only thrown if a handler dependency deadlock is encountered, and there are no alternate control flow mechanisms.  I've seen the suggestion before to prevent the save with javascript, but that doesn't stop creative users, and it doesn't stop web service calls either.<div>
<div><div><br></div><div>[1] <a href="http://trac.vtiger.com/cgi-bin/trac.cgi/browser/vtigercrm/branches/6.0.0/data/CRMEntity.php#L842">http://trac.vtiger.com/cgi-bin/trac.cgi/browser/vtigercrm/branches/6.0.0/data/CRMEntity.php#L842</a><br>
</div><div>[2] <a href="http://trac.vtiger.com/cgi-bin/trac.cgi/browser/vtigercrm/branches/6.0.0/include/events/VTEventTrigger.inc#L110">http://trac.vtiger.com/cgi-bin/trac.cgi/browser/vtigercrm/branches/6.0.0/include/events/VTEventTrigger.inc#L110</a></div>
</div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Apr 15, 2013 at 10:58 AM, Michał Janicki <span dir="ltr"><<a href="mailto:michal_janicki@wp.pl" target="_blank">michal_janicki@wp.pl</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="PL" link="blue" vlink="purple"><div><p class="MsoNormal"><span lang="EN-US">Hello,<u></u><u></u></span></p><p class="MsoNormal">
<span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-US">In the module (Accounts) I have a custom field. <u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US">In another, I have a function that validates that the field contains the correct values. <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">How do I stop the save field value where my function returns false?<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p><p class="MsoNormal">Regards,<u></u><u></u></p>
<p class="MsoNormal">Michal Janicki<u></u><u></u></p></div></div><br>_______________________________________________<br>
<a href="http://www.vtiger.com/" target="_blank">http://www.vtiger.com/</a><br></blockquote></div><br></div>