feat(downloads) add a downloads plugin

It can use the same (or different) files from the web root and will send them as downloads to the browser. See the example updates.
EvandroLG · Feb 22, 2023 · 5fe93a5 · 5fe93a5
1 parent 325e911
commit 5fe93a5
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Showing 5 changed files with 84 additions and 5 deletions.
diff --git a/example/app.lua b/example/app.lua
@@ -3,11 +3,18 @@ package.path = './src/?.lua;./src/?/init.lua;' .. package.path
 
 local Pegasus = require 'pegasus'
 local Compress = require 'pegasus.plugins.compress'
+local Downloads = require 'pegasus.plugins.downloads'
 
 local server = Pegasus:new({
-  port='9090',
-  location='/example/root/',
-  plugins = { Compress:new() }
+  port = '9090',
+  location = '/example/root/',
+  plugins = {
+    Downloads:new {
+      prefix = "downloads",
+      stripPrefix = true,
+    },
+    Compress:new(),
+  }
 })
 
 server:start(function(req)

diff --git a/example/copas.lua b/example/copas.lua
@@ -11,6 +11,7 @@ package.path = "./src/?.lua;./src/?/init.lua;"..package.path
 local Handler = require 'pegasus.handler'
 local copas = require('copas')
 local socket = require('socket')
+local Downloads = require 'pegasus.plugins.downloads'
 
 --- Creates a new server within the Copas scheduler.
 -- @tparam table opts options table.
@@ -81,7 +82,12 @@ assert(newPegasusServer{
   },
   location = '/example/root/',
   callback = nil,
-  plugins = {},
+  plugins = {
+    Downloads:new {
+      prefix = "downloads",
+      stripPrefix = true,
+    },
+  },
 })
 
 -- Start

diff --git a/example/root/index.html b/example/root/index.html
@@ -9,7 +9,9 @@
         <link href="style.css" media="all" rel="stylesheet">
     </head>
     <body>
-        <img src="1.jpg">
+        <a href="downloads/1.jpg">
+            <img src="1.jpg" />
+        </a><p>Click the image to download it!</p>
         <form method="POST">
             Name: <input type="text" name="name">
             Age: <input type="text" name="age">

diff --git a/rockspecs/pegasus-dev-1.rockspec b/rockspecs/pegasus-dev-1.rockspec
@@ -38,5 +38,6 @@ build = {
     ['pegasus.response'] = 'src/pegasus/response.lua',
     ['pegasus.compress'] = 'src/pegasus/compress.lua',
     ['pegasus.plugins.compress'] = 'src/pegasus/plugins/compress.lua',
+    ['pegasus.plugins.downloads'] = 'src/pegasus/plugins/downloads.lua'
   }
 }
diff --git a/src/pegasus/plugins/downloads.lua b/src/pegasus/plugins/downloads.lua
@@ -0,0 +1,63 @@
+--- A plugin that allows to download files via a browser.
+local Downloads = {}
+Downloads.__index = Downloads
+
+--- Creates a new plugin instance.
+-- The plugin will only respond to `GET` requests. The files will be served from the
+-- same `location` setting as defined in the `Handler`. The `prefix` is a virtual folder
+-- that triggers the plugin, but will be removed from the filepath if `stripPrefix` is truthy.
+-- If `stripPrefix` is falsy, then it should be a real folder.
+-- @tparam options table the options table with the following fields;
+-- @tparam[opt="downloads/"] options.prefix string the path prefix that triggers the plugin
+-- @tparam options.stripPrefix bool whether to strip the prefix from the file path when looking
+-- for the file in the filesystem. Defaults to `false`, unless `options.prefix` is omitted,
+-- then it defaults to `true`.
+function Downloads:new(options)
+  options = options or {}
+  self = {}
+
+  if not options.prefix then
+    self.prefix = "downloads/"
+    if options.stripPrefix == nil then
+      self.stripPrefix = true
+    else
+      self.stripPrefix = not not options.stripPrefix
+    end
+  else
+    self.prefix = options.prefix
+    self.stripPrefix = not not options.stripPrefix
+  end
+
+  self.prefix = "/" .. self.prefix .. "/"
+  while self.prefix:find("//") do
+    self.prefix = self.prefix:gsub("//", "/")
+  end
+
+  setmetatable(self, Downloads)
+
+  return self
+end
+
+function Downloads:newRequestResponse(request, response)
+  local stop = false
+  if request:method() ~= "GET" then
+    return stop -- we only handle GET requests
+  end
+
+  local path = request:path()
+  if path:find(self.prefix, nil, true) ~= 1 then
+    return stop -- doesn't match our prefix
+  end
+
+  local location = response._writeHandler.location or ""
+  local filename = path
+  if self.stripPrefix then
+    filename = path:sub(#self.prefix + 1, -1)
+  end
+
+  stop = not response:sendFile('.' .. location .. filename)
+  return stop
+end
+
+
+return Downloads