implement #26 : follow external urls

BACKLOG.md

@@ -2,17 +2,19 @@
 
 - [ ] maybe a virtual line in the 1st line that shows number of backlinks and maybe other interesting stuff
     - or put it as an extmark at the end of the first line, meh.
-- [ ] better support for #tags
-- [ ] some cool buffer showing backlinks (and stuff?)
+- [ ] better support for #tags [see also this comment](https://github.com/renerocksai/telekasten.nvim/discussions/23#discussioncomment-1754511)
+- [ ] some cool buffer showing backlinks (and stuff?) [see also this comment](https://github.com/renerocksai/telekasten.nvim/discussions/23#discussioncomment-1754511)
     - maybe another one where we dot-render a graph of linked notes and 
       display it via vimg from telescope_media_files or sth similar
     - these buffers / this buffer should keep its size even when resizing other
       splits (like the calendar)
 - [ ] really good support for special links: inserting, yanking, ...
+- [ ] lsp support, lsp completion of everything: notes, headings, paragraphs, tags, ...
 
 - [ ] yt video
 
 ## Dones
+- [x] follow external URLs
 - [x] telekasten filetype
 - [x] Telekasten command with completion, command palette
 - [x] follow #tags

lua/telekasten.lua

@@ -695,6 +695,30 @@ local function check_for_link_or_tag()
     return taglinks.is_tag_or_link_at(line, col, M.Cfg)
 end
 
+local function follow_url(url)
+    -- we just leave it to the OS's handler to deal with what kind of URL it is
+    local function format_command(cmd)
+        return 'call jobstart(["'
+            .. cmd
+            .. '", "'
+            .. url
+            .. '"], {"detach": v:true})'
+    end
+
+    local command
+    if vim.fn.has("mac") == 1 then
+        command = format_command("open")
+        vim.cmd(command)
+    else
+        if vim.fn.has("unix") then
+            command = format_command("xdg-open")
+            vim.cmd(command)
+        else
+            print("Cannot open URLs on your operating system")
+        end
+    end
+end
+
 --
 -- FollowLink:
 -- -----------
@@ -725,10 +749,18 @@ local function FollowLink(opts)
         search_mode = "tag"
         title = tag
     else
-        -- we are in a link
-        vim.cmd("normal yi]")
-        title = vim.fn.getreg('"0')
-        title = title:gsub("^(%[)(.+)(%])$", "%2")
+        if kind == "link" then
+            -- we are in a link
+            vim.cmd("normal yi]")
+            title = vim.fn.getreg('"0')
+            title = title:gsub("^(%[)(.+)(%])$", "%2")
+        else
+            -- we are in an external [link]
+            vim.cmd("normal yi)")
+            local url = vim.fn.getreg('"0')
+            print(url)
+            return follow_url(url)
+        end
 
         local parts = vim.split(title, "#")