Minor improvements in metadata processing script

1 files changed, 39 insertions, 33 deletions

diff --git a/scripts/metadata_filter.lua b/scripts/metadata_filter.lua
index 21f7759..b8a9059 100644
--- a/scripts/metadata_filter.lua
+++ b/scripts/metadata_filter.lua
@@ -1,9 +1,9 @@
 function format_date(date)
-    if date == nil then return date end
+    if not date then return date end
 
     date = pandoc.utils.normalize_date(pandoc.utils.stringify(date))
     local year, month, day = date:match("(%d%d%d%d)-(%d%d)-(%d%d)")
-    if year == nil then return nil end
+    if not year then return nil end
 
     local time = os.time({year = tonumber(year), month = tonumber(month), day = tonumber(day)})
     return pandoc.MetaMap({
@@ -41,9 +41,9 @@ function group_by(l, field, insert)
         local item = l[i]
         local f = field(item)
 
-        if f ~= nil then
+        if f then
             local out = insert(groups[f], f, item)
-            if out ~= nil then groups[f] = out end
+            if out then groups[f] = out end
         end
     end
 
@@ -86,7 +86,7 @@ function relative_to(dir, target)
 end
 
 function make_absolute(rel, base)
-    return rel:find("^/") ~= nil and rel or base:gsub("^(.*)/.-$", "%1") .. "/" .. rel
+    return rel:find("^/") and rel or base:gsub("^(.*)/.-$", "%1") .. "/" .. rel
 end
 
 function resolve_url(site_url, ref_file, target_file)
@@ -100,7 +100,7 @@ function resolve_url(site_url, ref_file, target_file)
 end
 
 function resolve_layout(layout)
-    if layout ~= nil then
+    if layout then
         layout = pandoc.utils.stringify(layout)
         return pandoc.MetaMap({id = layout, ["is_" .. layout] = pandoc.MetaBool(true)})
     end
@@ -119,7 +119,7 @@ function resolve_namespace(namespace)
 end
 
 function resolve_category(categories, category)
-    if categories ~= nil and category ~= nil then
+    if categories and category then
         category = pandoc.utils.stringify(category)
         data = pandoc.MetaMap(categories[category])
         data.id = category
@@ -144,7 +144,7 @@ function prep_menu(active_id, main_menu)
 end
 
 function process_pages(global, pages_by_id)
-    if pages_by_id == nil then pages_by_id = {} end
+    if not pages_by_id then pages_by_id = {} end
 
     local pages_list = pandoc.List()
 
@@ -153,13 +153,25 @@ function process_pages(global, pages_by_id)
         pages_list:insert(page)
     end
 
+    pages_list:sort(function(p1, p2)
+        if p1.date then
+            if p2.date then
+                return p1.date.yyyy_mm_dd > p2.date.yyyy_mm_dd
+            else
+                return true
+            end
+        elseif p2.date then
+            return false
+        else
+            return p1.title < p2.title
+        end
+    end)
+
     local pages_categorized = pages_list:filter(function(p) return p.category ~= nil end)
-    pages_categorized:sort(function(p1, p2) return p1.title < p2.title end)
 
-    local pages_by_category = group_by(pages_categorized,
-        function(p) return pandoc.utils.stringify(p.category.id) end)
-    pages_by_category = pandoc.MetaList(table_to_list(pages_by_category,
-        function(i1, i2) return i1.key < i2.key end))
+    local pages_by_category = group_by(pages_categorized, function(p) return p.category.id end)
+    pages_by_category =
+        table_to_list(pages_by_category, function(i1, i2) return i1.key < i2.key end)
 
     local pages_data = pandoc.MetaMap({
         all = pages_list,
@@ -167,16 +179,15 @@ function process_pages(global, pages_by_id)
         by_category = pages_by_category,
     })
 
-    local categories_data = group_by(pages_categorized, function(p)
-        return p.category and pandoc.utils.stringify(p.category.id)
-    end, function(stats, _, p)
-        if not stats then
-            return {name = p.category.name, count = 1}
-        else
-            stats.count = stats.count + 1
-        end
-    end)
-    categories_data = pandoc.MetaList(table_to_list(categories_data))
+    local categories_data = group_by(pages_categorized,
+        function(p) return p.category and p.category.id end, function(stats, _, p)
+            if not stats then
+                return {name = p.category.name, count = 1}
+            else
+                stats.count = stats.count + 1
+            end
+        end)
+    categories_data = table_to_list(categories_data)
 
     for i = 1, #categories_data do
         categories_data[i].value.count = ("%d"):format(categories_data[i].value.count)
@@ -190,21 +201,16 @@ function process(global, meta)
     meta.file_out = pandoc.utils.stringify(meta.file_out):gsub("^out", "")
     meta.layout = resolve_layout(meta.layout)
     meta.url = resolve_url(global.site.url, global.file_out, meta.file_out)
+    meta.title = (meta.title and pandoc.utils.stringify(meta.title)) or ""
 
-    if meta.title ~= nil then
-        meta.title = pandoc.utils.stringify(meta.title)
-    else
-        meta.title = ""
-    end
-
-    if meta.preview ~= nil then
+    if meta.preview then
         meta.preview = make_absolute(pandoc.utils.stringify(meta.preview), meta.file_out)
         meta.preview = resolve_url(global.site.url, global.file_out, meta.preview)
     end
 
-    if meta.date ~= nil then meta.date = format_date(meta.date) end
+    if meta.date then meta.date = format_date(meta.date) end
 
-    if meta.last_update ~= nil then
+    if meta.last_update then
         meta.last_update = format_date(meta.last_update)
     else
         meta.last_update = meta.date
@@ -212,7 +218,7 @@ function process(global, meta)
 
     meta.category = resolve_category(global.categories[meta.namespace.root.id], meta.category)
 
-    if meta.menus ~= nil and meta.menus.main ~= nil then
+    if meta.menus and meta.menus.main then
         meta.menus.main = prep_menu(meta.namespace.root.id, meta.menus.main)
     end