res_pjsip: Add clarifying documentation to PJSIP_HEADER help text

Added notes about when you can read or write headers. Specifically
about being able to read on the inbound channel and write on an
outbound channel.

ASTERISK-26063 #close
Reported by: Private Name
Tested by: Rusty Newton

Change-Id: Ibeb64af17d1f6451028b3c29855a3f151a01d8c5

diff --git a/res/res_pjsip_header_funcs.c b/res/res_pjsip_header_funcs.c
index 4ab3fb1d82886525630a1ea3d4f508a18dbc3114..5cb4a5ff195e310733cea24632b8d7f7124ef8f3 100644 (file)
--- a/res/res_pjsip_header_funcs.c
+++ b/res/res_pjsip_header_funcs.c
@@ -39,7 +39,8 @@
 /*** DOCUMENTATION
        <function name="PJSIP_HEADER" language="en_US">
                <synopsis>
-                       Gets, adds, updates or removes the specified SIP header from a PJSIP session.
+                       Gets headers from an inbound PJSIP channel. Adds, updates or removes the
+                       specified SIP header from an outbound PJSIP channel.
                </synopsis>
                <syntax>
                        <parameter name="action" required="true">
@@ -75,6 +76,10 @@
 
                </syntax>
                <description>
+                       <para>PJSIP_HEADER allows you to read specific SIP headers from the inbound
+                       PJSIP channel as well as write(add, update, remove) headers on the outbound
+                       channel. One exception is that you can read headers that you have already
+                       added on the outbound channel.</para>
                        <para>Examples:</para>
                        <para>;</para>
                        <para>; Set 'somevar' to the value of the 'From' header.</para>
@@ -120,7 +125,7 @@
 
                        <note><para>If you call PJSIP_HEADER in a normal dialplan context you'll be
                        operating on the <emphasis>caller's (incoming)</emphasis> channel which
-                       may not be what you want.  To operate on the <emphasis>callee's (outgoing)</emphasis>
+                       may not be what you want. To operate on the <emphasis>callee's (outgoing)</emphasis>
                        channel call PJSIP_HEADER in a pre-dial handler. </para>
                        <para>Example:</para>
                        <para>;</para>