Updated to support string tags and added startAfter & endBefore

You can now specify the start and end of code blocks via string labels. 

This greatly improves the experience because you can edit the source file and rely on the string labels to grab the correct code blocks.

No more adjusting line numbers after making edits

Author: epinzur

_extensions/include-code-files/include-code-files.lua

@@ -10,54 +10,128 @@ end
 
 --- Filter function for code blocks
 local function transclude (cb)
+  local content = ""
+
   if cb.attributes.include then
-    local content = ""
     local fh = io.open(cb.attributes.include)
     if not fh then
       io.stderr:write("Cannot open file " .. cb.attributes.include .. " | Skipping includes\n")
+      goto cleanup
+    end
+
+    -- change hyphenated attributes to PascalCase
+    for i,pascal in pairs({"startLine", "endLine", "startAfter", "endBefore"})
+    do
+        local hyphen = pascal:gsub("%u", "-%0"):lower()
+        if cb.attributes[hyphen] then
+          cb.attributes[pascal] = cb.attributes[hyphen]
+          cb.attributes[hyphen] = nil
+        end
+    end
+
+    if cb.attributes.startLine and cb.attributes.startAfter then
+      io.stderr:write("Cannot specify both startLine and startAfter | Skipping includes\n")
+      goto cleanup
+    end
+
+    if cb.attributes.endLine and cb.attributes.endBefore then
+      io.stderr:write("Cannot specify both endLine and endBefore | Skipping includes\n")
+      goto cleanup
+    end
+
+    local number = 0
+    local start = nil
+    local finish = nil
+    local skipFirst = false
+    local skipLast = false
+
+    -- set start and skipFirst based on start params
+    if cb.attributes.startLine then
+      start = tonumber(cb.attributes.startLine)
+      if not start then
+        start = cb.attributes.startLine
+      end
+    elseif cb.attributes.startAfter then
+      start = tonumber(cb.attributes.startAfter)
+      if not start then
+        start = cb.attributes.startAfter
+      end
+      skipFirst = true
     else
-      local number = 1
-      local start = 1
-
-      -- change hyphenated attributes to PascalCase
-      for i,pascal in pairs({"startLine", "endLine"})
-      do
-         local hyphen = pascal:gsub("%u", "-%0"):lower()
-         if cb.attributes[hyphen] then
-            cb.attributes[pascal] = cb.attributes[hyphen]
-            cb.attributes[hyphen] = nil
-         end
-      end
-
-      if cb.attributes.startLine then
-        cb.attributes.startFrom = cb.attributes.startLine
-        start = tonumber(cb.attributes.startLine)
-      end
-      for line in fh:lines ("L")
-      do
-        if cb.attributes.dedent then
-          line = dedent(line, cb.attributes.dedent)
+      -- if no start specified, start at the first line
+      start = 1
+    end
+
+    quarto.log.output("start: " .. start)
+
+    -- set finish and skipLast based on end params
+    if cb.attributes.endLine then
+      finish = tonumber(cb.attributes.endLine)
+      if not finish then
+        finish = cb.attributes.endLine
+      end
+    elseif cb.attributes.endBefore then
+      finish = tonumber(cb.attributes.endBefore)
+      if not finish then
+        finish = cb.attributes.endBefore
+      end
+      skipLast = true
+    else
+      -- if no end specified, end at the last line
+    end
+
+    quarto.log.output("finish: " .. finish)
+
+    for line in fh:lines ("L")
+    do
+      number = number + 1
+      -- if start or finish is a string, check if it exists on the current line
+      if type(start) == "string" and string.find(line, start, 1, true) then
+        start = number
+        quarto.log.output("convererted start to : " .. start)
+      elseif type(finish) == "string" and string.find(line, finish, 1 , true) then
+        finish = number
+        quarto.log.output("convererted finish to : " .. finish)
+      end
+
+      -- if haven't found start yet, then continue
+      if start and type(start) == "number" then
+        if number < start or (number == start and skipFirst) then
+          goto continue
         end
-        if number >= start then
-          if not cb.attributes.endLine or number <= tonumber(cb.attributes.endLine) then
-            content = content .. line
-          end
+      elseif start then
+        -- else if start is still a string, then continue
+        goto continue
+      end
+
+      -- if found finish, then end
+      if finish and type(finish) == "number" then
+        if number > finish or (number == finish and skipLast) then
+          break
         end
-        number = number + 1
-      end 
-      fh:close()
-    end     
-    -- remove key-value pair for used keys
-    cb.attributes.include = nil
-    cb.attributes.startLine = nil
-    cb.attributes.endLine = nil
-    cb.attributes.dedent = nil
-    -- return final code block
-    return pandoc.CodeBlock(content, cb.attr)
+      end
+
+      if cb.attributes.dedent then
+        line = dedent(line, cb.attributes.dedent)
+      end
+
+      content = content .. line
+      ::continue::
+    end
+    fh:close()
   end
+  ::cleanup::
+  -- remove key-value pair for used keys
+  cb.attributes.include = nil
+  cb.attributes.startLine = nil
+  cb.attributes.startAfter = nil
+  cb.attributes.endLine = nil
+  cb.attributes.endBefore = nil
+  cb.attributes.dedent = nil
+  -- return final code block
+  return pandoc.CodeBlock(content, cb.attr)
 end
 
 return {
   { CodeBlock = transclude }
 }
-