template-parser: renderer: implemented 'else' support in templates

yeah, this is stupid. after more than 320 commits and 26 releases, we
finally support the 'else' statement in the template engine. I don't
know if I'm dumb or what, but it took me that long to find a "simple"
solution to this basic issue. yep, no more
`{% ifdef FOO %}...{% endif %}{% ifndef FOO %}...{% endif %}` blocks.
but seriously, who cares?! :/

1 files changed, 11 insertions, 3 deletions

diff --git a/man/blogc-template.7.ronn b/man/blogc-template.7.ronn
index 3499d7c..1fdc479 100644
--- a/man/blogc-template.7.ronn
+++ b/man/blogc-template.7.ronn
@@ -143,7 +143,8 @@ based on the value and existence of variables in the current scope.
 The implementation of conditionals is simple, and each will just evaluate the
 value of a single variable.
 
-The available conditionals are: `ifdef`, `ifndef` and `if`.
+The available conditionals are: `ifdef`, `ifndef` and `if`. `else` statements
+are supported.
 
 ### ifdef conditional
 
@@ -154,9 +155,12 @@ This is how an `ifdef` conditional is defined in a template:
 
     {% ifdef TITLE %}
     This is title: {{ TITLE }}
+    {% else %}
+    Untitled entry
     {% endif %}
 
-In this case, if the `TITLE` variable is defined, the content is included.
+In this case, if the `TITLE` variable is defined, the content after the statement
+is included. Otherwise, the content after `else` statement is included.
 
 ### ifndef conditional
 
@@ -170,6 +174,8 @@ This is how an `ifndef` conditional is defined in a template:
     {% endif %}
 
 In this case, if the `TITLE` variable is not defined, the content is included.
+`else` statements are supported here, even if it does not makes much sense to
+be used this way.
 
 ### if conditional
 
@@ -184,7 +190,9 @@ comparisions are strcmp(3)-like.
 This is how an `if` conditional is defined in a template:
 
     {% if TITLE == "My Title" %}
-    Title is "My Title"
+    Special description of "My Title"
+    {% else %}
+    Title is {{ TITLE }}
     {% endif %}
 
 Or: