add template::index

2 files changed, 43 insertions, 1 deletions

diff --git a/README.md b/README.md
index ad8c310..6aa4ceb 100644
--- a/README.md
+++ b/README.md
@@ -145,6 +145,29 @@ Multiline template line 9
 Multiline template line 10
 ```
 
+Another thing you can do is to insert an index with links to similar blog posts. E.g.:
+
+```
+See more entries about DTail:
+
+<< template::index dtail
+
+Blablabla...
+```
+
+... scans all other post entries with `dtail` in the file name and generates a link list like this:
+
+```
+See more entries about DTail:
+
+=> ./2022-10-30-installing-dtail-on-openbsd.gmi 2022-10-30 Installing DTail on OpenBSD
+=> ./2022-03-06-the-release-of-dtail-4.0.0.gmi 2022-03-06 The release of DTail 4.0.0
+=> ./2021-04-22-dtail-the-distributed-log-tail-program.gmi 2021-04-22 DTail - The distributed log tail program (You are currently reading this)
+
+Blablabla...
+```
+
+
 ### Alternative configuration file path
 
 If you don't want to mess with `gemtexter.conf`, you can use an alternative config file path in `~/.config/gemtexter.conf`, which takes precedence if it exists. Another way is to set the `CONFIG_FILE_PATH` environment variable, e.g.:
diff --git a/lib/template.source.sh b/lib/template.source.sh
index c1487ba..c4d054d 100644
--- a/lib/template.source.sh
+++ b/lib/template.source.sh
@@ -21,10 +21,12 @@ template::_generate_file () {
     local -r dest="${tpl/.tpl/}"
 
     cd "$tpl_dir" || log PANIC "Unable to chdir to $tpl_dir"
-    log INFO "$tpl_path -> $dest"
+    log INFO "Generating $tpl_path -> $dest"
 
+    export CURRENT_GMI="$dest" # Environt var can be used by .gmi.tpl
     template::_generate < "$tpl" > "$dest.tmp"
     mv "$dest.tmp" "$dest"
+    log INFO "Done generating $dest"
     cd -
 }
 
@@ -62,6 +64,23 @@ template::_line () {
     eval "${1/<< /}"
 }
 
+# Can be used from a .gmi.tpl template for generating an index for a given topic.
+template::index () {
+    local -r topic="$1"; shift
+
+    while read -r gmi_file; do
+        local date=$(cut -d- -f1,2,3 <<< "$gmi_file")
+        local title=$($SED -n "/^# / { s/# //; p; q; }" "$gmi_file")
+
+        local current=''
+        if [ "$gmi_file" = "$CURRENT_GMI" ]; then
+            current=" (You are currently reading this)"
+        fi
+
+        echo "=> ./$gmi_file $date $title$current"
+    done < <(ls | $GREP "$topic.*\\.gmi\$" | sort -r)
+}
+
 template::test () {
     assert::equals "$(template::_line '<< echo -n foo')" 'foo'
     assert::equals "$(template::_line '<< echo foo')" 'foo'