add load_paths

README.org

@@ -31,6 +31,9 @@ you to add anything extra to your ~init.el~.
   opts = {
     -- by default, none are enabled
     langs = { "python", "lua", ... }
+
+    -- paths to emacs packages to additionally load
+    load_paths = {}
   }
 },
 #+end_src
@@ -67,3 +70,37 @@ Tangles all blocks in range. If the range is NOT ~%~, the tangled file will
 likely only contain the contents of the last block, which is expected
 behaviour.
 
+** Advanced Configuration
+*** Adding extra org-mode languages
+
+Your emacs ~init.el~ will *not* be sourced during execution of ~:OrgExecute~ and
+~:OrgTangle~, so packages you install there wont be available.
+
+However, ~orgmode-babel.nvim~ allows us to specify extra load paths, so we can
+make packages available that way.
+
+**** Example
+
+As an example, lets add [[https://github.com/arnm/ob-mermaid][ob-mermaid]] for
+mermaid functionality in ~orgmode-babel.nvim~!
+
+We have two options to get the package. We could either create an
+=~/.emacs.d/init.el= and install it through a package manager, which will likely
+have a randomish name, or for the sake of simplicity and this being a neovim
+plugin, we can simply manually clone the repo to a known location.
+
+#+begin_example
+git clone https://github.com/arnm/ob-mermaid ~/.../clone-location/ob-mermaid
+#+end_example
+
+#+begin_src lua
+{
+  "mrshmllow/orgmode-babel.nvim",
+  ...
+  opts = {
+    langs = { ..., "mermaid" }
+    load_paths = { "~/.../clone-location/ob-mermaid" }
+  }
+},
+#+end_src
+

lua/orgmode-babel/init.lua

@@ -6,6 +6,7 @@ function M.setup(opts)
 	opts = opts or opts
 
 	M.langs = opts.langs and opts.langs or {}
+	M.load_paths = opts.load_paths and opts.load_paths or {}
 
 	M._here = vim.fn.fnamemodify(debug.getinfo(1).source:sub(2), ":p:h")
 	M._run_by_name = M._here .. "/run_by_name.el"
@@ -26,6 +27,17 @@ function M.setup(opts)
 		"(setq make-backup-files nil)",
 	}
 
+	vim.list_extend(
+		M._base_cmd,
+		vim.fn.reduce(M.load_paths, function(acc, value)
+			vim.list_extend(acc, {
+				"--eval",
+				[[(add-to-list 'load-path "]] .. value .. [[")]],
+			})
+			return acc
+		end, {})
+	)
+
 	vim.list_extend(M._base_cmd, {
 		"--eval",
 		"(org-babel-do-load-languages 'org-babel-load-languages '(" .. vim.fn.reduce(M.langs, function(acc, value)