Lua is a very fast and powerful scripting language that can be easily embeddable. It has been shining in industries like game development, for example. Lua is also an excellent tool as a general purpose language and can be used to develop robust applications. Its use in web developments, however, despite its great potential and incredible benchmarks, needs to be more widespread. This talk will mention the current state of Lua in web development, show some benchmarks, compare existing tools and teach how to get started with Sailor, an MVC web framework written in Lua.
15. @etiene_dCoding Serbia 2015
Better Reasons
• It looks cool
(I heard you could make games with it)
• It’s made in my home country
(In my university to be more precise)
16. @etiene_dCoding Serbia 2015
• It looks cool
(I heard you could make games with it)
• It’s made in my home country
(In my university to be more precise)
• It’s easy to learn
Better Reasons
17. @etiene_dCoding Serbia 2015
-- Cipher module
--[[ Based on algorithms/caesar_cipher.lua
by Roland Yonaba ]]
local cipher = {}
local function ascii_base(s)
return s:lower() == s and ('a'):byte() or ('A'):byte()
end
function cipher.caesar( str, key )
return str:gsub('%a', function(s)
local base = ascii_base(s)
return string.char(((s:byte() - base + key) % 26) + base)
end)
end
return cipher
One slide crash course: cipher module
18. @etiene_dCoding Serbia 2015
-- Cipher module
--[[ Based on algorithms/caesar_cipher.lua
by Roland Yonaba ]]
local cipher = {}
local function ascii_base(s)
return s:lower() == s and ('a'):byte() or ('A'):byte()
end
function cipher.caesar( str, key )
return str:gsub('%a', function(s)
local base = ascii_base(s)
return string.char(((s:byte() - base + key) % 26) + base)
end)
end
return cipher
One slide crash course: cipher module
19. @etiene_dCoding Serbia 2015
-- Cipher module
--[[ Based on algorithms/caesar_cipher.lua
by Roland Yonaba ]]
local cipher = {}
local function ascii_base(s)
return s:lower() == s and ('a'):byte() or ('A'):byte()
end
function cipher.caesar( str, key )
return str:gsub('%a', function(s)
local base = ascii_base(s)
return string.char(((s:byte() - base + key) % 26) + base)
end)
end
return cipher
One slide crash course: cipher module
20. @etiene_dCoding Serbia 2015
-- Cipher module
--[[ Based on algorithms/caesar_cipher.lua
by Roland Yonaba ]]
local cipher = {}
local function ascii_base(s)
return s:lower() == s and ('a'):byte() or ('A'):byte()
end
function cipher.caesar( str, key )
return str:gsub('%a', function(s)
local base = ascii_base(s)
return string.char(((s:byte() - base + key) % 26) + base)
end)
end
return cipher
One slide crash course: cipher module
21. @etiene_dCoding Serbia 2015
-- Cipher module
--[[ Based on algorithms/caesar_cipher.lua
by Roland Yonaba ]]
local cipher = {}
local function ascii_base(s)
return s:lower() == s and ('a'):byte() or ('A'):byte()
end
function cipher.caesar( str, key )
return str:gsub('%a', function(s)
local base = ascii_base(s)
return string.char(((s:byte() - base + key) % 26) + base)
end)
end
return cipher
One slide crash course: cipher module
22. @etiene_dCoding Serbia 2015
-- Cipher module
--[[ Based on algorithms/caesar_cipher.lua
by Roland Yonaba ]]
local cipher = {}
local function ascii_base(s)
return s:lower() == s and ('a'):byte() or ('A'):byte()
end
function cipher.caesar( str, key )
return str:gsub('%a', function(s)
local base = ascii_base(s)
return string.char(((s:byte() - base + key) % 26) + base)
end)
end
return cipher
One slide crash course: cipher module
23. @etiene_dCoding Serbia 2015
-- Cipher module
--[[ Based on algorithms/caesar_cipher.lua
by Roland Yonaba ]]
local cipher = {}
local function ascii_base(s)
return s:lower() == s and ('a'):byte() or ('A'):byte()
end
function cipher.caesar( str, key )
return str:gsub('%a', function(s)
local base = ascii_base(s)
return string.char(((s:byte() - base + key) % 26) + base)
end)
end
return cipher
One slide crash course: cipher module
26. @etiene_dCoding Serbia 2015
“ I have myself developed Web sites with pure C++, Java, C#, PHP, and Python.
The easiest way to go was definitely Python. If the libraries existed, Lua would be
not quite as easy to use as Python, but probably quite a bit more efficient; I think it
would become my first choice... if the libraries existed.” Michael Gogins
“ Recently there was some discussion about mod_lua on the Apache developers
mailing list. I mentioned there that I feel Lua could replace PHP as the number one
web scripting language if mod_lua were stable (i.e. not still in beta) and it were
implemented well (not making some of PHP's mistakes such as putting everything
in the global scope with no consistent naming or parameter schemes). I've wanted
to use Lua for all the things I currently use PHP for ever since I discovered it.” Rena
42. @etiene_dCoding Serbia 2015
Frameworks
Orbit (2007)
Least known
No significant updates since 2010
MVC
Luvit (2011)
Most popular
Intense development
node.js port 2-4x faster
Needs a better documentation
44. @etiene_dCoding Serbia 2015
Frameworks
Lapis (2012)
Intense development
Moonscript and Lua
Very well documented
Templater
OpenResty only
Not MVC
Others
Complicated, abandoned, poorly documented, license
issues or I never heard about it...
49. @etiene_dCoding Serbia 2015
What exactly is
Sailor?
• It’s an MVC web framework
• Completely written in Lua
• Compatible with Apache (mod_lua), Nginx (OpenResty),
Xavante, Mongoose, Lighttpd and Lwan
• Compatible with Linux, Windows and Mac
• Compatible with different databases
• MIT License
• Pre alpha v0.4 (Chibi)
• 0.5 (Pluto) will be released soon!
51. @etiene_dCoding Serbia 2015
What (else) is cool about
Sailor?
• Routing and friendly URLs
• Session, cookies, include, redirect…
• Lua Pages parsing
• Mail sending
• Simple Object Relational-Mapping
• Validation (valua)
• Basic login and authentication modules
• Form generation
• Themes (Bootstrap integration out of the box)
• App generator (Linux and Mac only)
• Model and CRUD generator
• Automated tests
52. @etiene_dCoding Serbia 2015
• Routing and friendly URLs
• Session, cookies, include, redirect…
• Lua Pages parsing
• Mail sending
• Simple Object Relational-Mapping
• Validation (valua)
• Basic login and authentication modules
• Form generation
• Themes (Bootstrap integration out of the box)
• App generator (Linux and Mac only)
• Model and CRUD generator
• Automated tests
• Lua at client
What (else) is cool about
Sailor?
53. @etiene_dCoding Serbia 2015
Not so great things
• It’s still in early development
• Things are changing fast
• It lacks features
• Documentation
54. @etiene_dCoding Serbia 2015
How to get Sailor!
$ luarocks install sailor
$ sailor create ‘My App’ /var/www
$ cd /var/www/my_app
$ lua start-server.lua
59. @etiene_dCoding Serbia 2015
Example!
-- /controllers/site.lua
local site = {}
function site.index(page)
local msg = “Hello World”
page:render(‘index’, { msg = msg } )
end
function site.notindex(page)
page.theme = nil
page:write(“I’m different!”)
end
return site
60. @etiene_dCoding Serbia 2015
<!-- /views/site/index.lp —>
<p>
A message from the server:
<?lua page:print(msg) ?>
<br/>
The message again:
<%= msg %> <!-- syntactic sugar: same thing as above —>
</p>
Example!
62. @etiene_dCoding Serbia 2015
<?lua@server -- Code here runs on the server ?>
<?lua -- Same as above ?>
<?lua@client -- Runs at the client ?>
<?lua@both -- Runs at the server and the client ?>
<?lua@both
another_msg = “Another message”
?>
<?lua page:print(another_msg) ?>
<?lua@client
js.window.alert(another_msg)-- Sailor v0.4
-- window:alert(another_msg)
-- ^ Sailor v0.5
?>
Example!
64. @etiene_dCoding Serbia 2015
local user = {}
local v = require “valua” -- validation module
user.attributes = {
{ id = “safe” },
{ name = v:new().not_empty().len(6,50) }
}
user.db = {
key = ‘id’,
table = ‘users’
}
user.relations = {
posts = { -- u.posts
relation = “HAS_MANY”, model = “post”, attribute = “author_id”
}
}
return user
Example!
65. @etiene_dCoding Serbia 2015
local user = {}
local v = require “valua” -- validation module
user.attributes = {
{ id = “safe” },
{ name = v:new().not_empty().len(6,50) }
}
user.db = {
key = ‘id’,
table = ‘users’
}
user.relations = {
posts = { -- u.posts
relation = “HAS_MANY”, model = “post”, attribute = “author_id”
}
}
return user
Example!
66. @etiene_dCoding Serbia 2015
-- /controllers/site.lua
local site = {}
function site.index(page)
local User = sailor.model(‘user’)
local u = User:new()
u.name = ‘Arnold’
local msg
if u:save() then
msg = ‘Success’
else
msg = table.unpack(u.errors)
end
local users = User:find_all()
page:render(‘index’, { msg = msg, users = users } )
end
return site
Example!