Adding a link to an invoice into a notification message - html

Question

I have a screen with a form contaning invoices I want to notify the user with. The screen is used as bodyScreenLocation for the EmailTemplate. Up to here, it works. I wanted to add a link for each invoice so that the user can open the document right from withing the message. How to construct the path? This way it does not work:
This field is created in a form, that is included in a screen. This screen is used in a template called using
<service-call name="org.moqui.impl.EmailServices.send#EmailTemplate" async="true">
Added 18.10.2016
I attempted to use your advice.
<actions>
<entity-find entity-name="mantle.account.invoice.Invoice" list="invoiceList"/>
<script>
import org.moqui.impl.context.WebFacadeImpl
def httpUrl = WebFacadeImpl.getWebappRootUrl('webroot',null,false,false,ec)
</script>
</actions>
This is the log:
21:47:18.996 WARN oquiWorker-2 o.moqui.i.c.TransactionFacadeImpl Transaction set rollback only. The rollback was originally caused by: Error rendering screen [component://HS-data/screen/Notification/PayablesDue.xml]
java.lang.NullPointerException: null
at org.moqui.impl.context.WebFacadeImpl.makeWebappHost(WebFacadeImpl.groovy:477) ~[moqui-framework-2.0.0.jar:2.0.0]
at org.moqui.impl.context.WebFacadeImpl.makeWebappRootUrl(WebFacadeImpl.groovy:520) ~[moqui-framework-2.0.0.jar:2.0.0]
at org.moqui.impl.context.WebFacadeImpl.getWebappRootUrl(WebFacadeImpl.groovy:467) ~[moqui-framework-2.0.0.jar:2.0.0]
at org.moqui.impl.context.WebFacadeImpl$getWebappRootUrl.call(Unknown Source) ~[?:?]
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48) ~[groovy-2.4.7.jar:2.4.7]
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113) ~[groovy-2.4.7.jar:2.4.7]
at PayablesDue_xml_screen_actions.run(PayablesDue_xml_screen_actions:11) ~[script:?]

Answer 1

What you're looking for is the WebFacade.getWebappRootUrl() method. Use a call that is something like this in your template to get the base URL:
ec.web.getWebappRootUrl(true, null)
When there is no WebFacade in place, such as when running in an async service, you'll have to drop a level lower and there is a static method in WebFacadeImpl for this (it's not so convenient when you don't have the standard interfaces to go through), here is the method signature:
String getWebappRootUrl(String webappName, String servletContextPath, boolean requireFullUrl, Boolean useEncryption, ExecutionContextImpl eci)
The standard webappName is 'webroot' and unless you're doing something fancy in your Moqui Conf XML file this can be a static String. The servletContextPath can be null or an empty String if your Moqui webapp is mounted on the root (commonly the case; without a request where we can get to the ServletContext to see where it is mounted this can't be determined automatically).