templates: add initials function

When listing all addresses with names, in for example the To field, one
might end up with a very long string. Add the initials function, which
extracts the names from addresses and then shortens each of them to the
initials of the name.

Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
Acked-by: Robin Jarry <robin@jarry.cc>

2 files changed, 25 insertions, 0 deletions

diff --git a/doc/aerc-templates.7.scd b/doc/aerc-templates.7.scd
index bfba05c4..f5998b23 100644
--- a/doc/aerc-templates.7.scd
+++ b/doc/aerc-templates.7.scd
@@ -196,6 +196,16 @@ aerc provides the following additional functions:
 	{{index (.To | names) 0}}
 	```
 
+*initials*
+	Extracts the initials from the names part from a mail.Address list. If
+	there is no name available, the first letter of the email address is
+	returned instead.
+
+	```
+	{{.To | initials | join ", "}}
+	{{index (.To | initials) 0}}
+	```
+
 *emails*
 	Extracts the addresses part from a mail.Address list.
 
diff --git a/lib/templates/functions.go b/lib/templates/functions.go
index f6cb0df4..630db264 100644
--- a/lib/templates/functions.go
+++ b/lib/templates/functions.go
@@ -120,6 +120,20 @@ func names(addresses []*mail.Address) []string {
 	return n
 }
 
+func initials(addresses []*mail.Address) []string {
+	n := names(addresses)
+	ret := make([]string, len(addresses))
+	for i, name := range n {
+		split := strings.Split(name, " ")
+		initial := ""
+		for _, s := range split {
+			initial += string([]rune(s)[0:1])
+		}
+		ret[i] = initial
+	}
+	return ret
+}
+
 func emails(addresses []*mail.Address) []string {
 	e := make([]string, len(addresses))
 	for i, addr := range addresses {
@@ -208,6 +222,7 @@ var templateFuncs = template.FuncMap{
 	"exec":          cmd,
 	"version":       func() string { return version },
 	"names":         names,
+	"initials":      initials,
 	"emails":        emails,
 	"mboxes":        mboxes,
 	"persons":       persons,