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website - make docs html
author Franklin Schmidt <fschmidt@gmail.com>
date Thu, 07 Feb 2019 23:00:20 -0700
parents website/src/tutorial.html.luan@1660136ac451
children 29d6d7d79c41
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1324:1660136ac451 1325:28c1fc6d9d29
1 <!doctype html>
2 <html>
3 <head>
4 <title>Luan Tutorial</title>
5 <style>
6 @import "/site.css";
7 </style>
8 </head>
9 <body>
10
11 <div small><a href="/">Luan</a></div>
12
13 <h1>Luan Tutorial</h1>
14
15
16 <p>Create a file <b>hello.luan</b> containing:</p>
17
18 <pre>
19 %>
20 Hello World
21 <%
22 </pre>
23
24 <p>To run this, type <b>luan hello.luan</b> on the command line. This should print <b>Hello World</b>.</p>
25
26 <p>The syntax here is based on <a href="http://en.wikipedia.org/wiki/JavaServer_Pages">JSP</a>. Let's change it a little:</p>
27
28 <pre>
29 local name = "Bob"
30 %>
31 Hello <%= name %>
32 <%
33 </pre>
34
35 <p>This should print <b>Hello Bob</b>. Now let's try a more conventional approach:</p>
36
37 <pre>
38 local Io = require "luan:Io.luan"
39 local print = Io.print
40
41 print("Hello World")
42 </pre>
43
44 <p>In Luan, a function call with one string argument doesn't require parenthesis, so <b>print("Hello World")</b> is the same as <b>print "Hello World"</b> and <b>require "luan:Io.luan"</b> is the same as <b>require("luan:Io.luan")</b>. Both <b>require</b> and <b>print</b> are functions.</p>
45
46 <p>The <b>require</b> function takes a <a href="http://en.wikipedia.org/wiki/Uniform_resource_identifier">URI</a> as an argument. Examples of URIs are "<b>luan:Io.luan</b>" and "<b>file:hello.luan</b>". <b>require</b> is used to import a module, which is returned from the <b>require</b> function call. In the case above, we assign the module to the local variable <b>Io</b>. The function <b>print</b> is a member of this module. We could have done <b>Io.print("Hello World")</b> but instead we chose to assign <b>print</b> to a local variable and use that to call the function.</p>
47
48 <p>Luan starts with only two defined functions: <b>require</b> and <b>java</b>. You will use <b>require</b> to import whatever you need. This is a little more work, but makes it clear in each file where each function comes from.</p>
49
50 <p>Let's a make fancier version:</p>
51
52 <pre>
53 local Io = require "luan:Io.luan"
54 local print = Io.print
55
56 local function hello(name)
57 print("Hello "..name)
58 end
59
60 hello("Bob")
61 </pre>
62
63 <p>The <b>..</b> operator does concatenation. This will print <b>Hello Bob</b>.</p>
64
65 <p>Now let's make a web page. First we need a directory for our website. So create a directory <b>site</b>. In this directory, create a file <b>hi.html.luan</b> containing:
66
67 <pre>
68 local Io = require "luan:Io.luan"
69 local Http = require "luan:http/Http.luan"
70
71 return function()
72 Io.stdout = Http.response.text_writer()
73 %>
74 &lt;!doctype html>
75 &lt;html>
76 &lt;body>
77 Hello World
78 &lt;/body>
79 &lt;/html>
80 <%
81 end
82 </pre>
83
84 <p>Now go back to the parent directory and do <b>luan luan:http/serve.luan file:site</b>. This will run the Luan web server on port 8080. Try going to <a href="http://localhost:8080/">http://localhost:8080/</a>. You should see the directory. If you click on <b>hi.html.luan</b> you will see the source. But if you remove the <b>.luan</b> and just go to <a href="http://localhost:8080/hi.html">http://localhost:8080/hi.html</a> then you will run the program which will generate the web page.</p>
85
86 <p>The Luan webserver expects the file to return a function and calls it to generate the page. Code of the form <b>%>...<%</b> writes its output to <b>Io.stdout</b> which by default is the standard output of the command line. So in the returned function one usually starts by setting <b>Io.stdout</b> to a <code>text_writer</code> which writes its output to the HTTP response (to the web browser).</p>
87
88 <p>You can find this example and others in the <a href="examples/">examples directory</a>. Take a look at <a href="examples/hi2.luan">hi2.luan</a> next. Remember to remove the <b>.luan</b> from the URL to run the code.</p>
89
90 <p>So now you have built your website and you want to publish it to the web. If you have your own domain, create a CNAME record for it pointing to <b>s1.luan.ws</b>. If you don't have a domain, just use a domain like <b>bob.s1.luan.ws</b> (anything of the form <b>*.s1.luan.ws</b>). Assuming your directory is <b>site</b> and you will use the password <b>secret</b>, do the following from the command line:
91
92 <pre>
93 luan luan:host/push.luan bob.s1.luan.ws secret site
94 </pre>
95
96 <p>The form is <b>luan luan:host/push.luan domain password directory</b>. If you change your site, just run this again and your site will be updated. To delete your site, do <b>luan luan:host/delete.luan domain password</b>.</p>
97
98 <p>Hopefully this short tutorial gave you an idea of how to use Luan to make a website.</p>
99
100 </body>
101 </html>