Mercurial Hosting > luan
diff website/src/tutorial.html.luan @ 1651:5b8f056527a3
docs work
| author | Franklin Schmidt <fschmidt@gmail.com> |
|---|---|
| date | Thu, 31 Mar 2022 16:13:32 -0600 |
| parents | website/src/tutorial.html@7eddf1e990c0 |
| children | d5779a264a4a |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/website/src/tutorial.html.luan Thu Mar 31 16:13:32 2022 -0600 @@ -0,0 +1,114 @@ +local Luan = require "luan:Luan.luan" +local error = Luan.error +local Io = require "luan:Io.luan" +local Http = require "luan:http/Http.luan" +local Shared = require "site:/lib/Shared.luan" +local head = Shared.head or error() +local header = Shared.header or error() + + +return function() + Io.stdout = Http.response.text_writer() +%> +<!doctype html> +<html> + <head> +<% head() %> + <title>Luan Tutorial</title> + </head> + <body> +<% header{[[<a href="docs.html">Documentation</a>]]} %> + <div content> + +<h1>Luan Tutorial</h1> + + +<p>Create a file <b>hello.luan</b> containing:</p> + +<pre> + %> + Hello World + <% +</pre> + +<p>To run this, type <b>luan hello.luan</b> on the command line. This should print <b>Hello World</b>.</p> + +<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> + +<pre> + local name = "Bob" + %> + Hello <%= name %> + <% +</pre> + +<p>This should print <b>Hello Bob</b>. Now let's try a more conventional approach:</p> + +<pre> + local Io = require "luan:Io.luan" + local print = Io.print + + print("Hello World") +</pre> + +<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> + +<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> + +<p>Luan starts with only one defined function: <b>require</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> + +<p>Let's a make fancier version:</p> + +<pre> + local Io = require "luan:Io.luan" + local print = Io.print + + local function hello(name) + print("Hello "..name) + end + + hello("Bob") +</pre> + +<p>The <b>..</b> operator does concatenation. This will print <b>Hello Bob</b>.</p> + +<p>Now let's make a web page. First we need a directory for our website. So create a directory <b>src</b>. In this directory, create a file <b>hi.html.luan</b> containing: + +<pre> + local Io = require "luan:Io.luan" + local Http = require "luan:http/Http.luan" + + return function() + Io.stdout = Http.response.text_writer() + %> + <!doctype html> + <html> + <body> + Hello World + </body> + </html> + <% + end +</pre> + +<p>Now go back to the parent directory and do <b>luan luan:http/serve.luan src</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> + +<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> + +<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> + +<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.software</b>. If you don't have a domain, just use a domain like <b>bob.s1.luan.software</b> (anything of the form <b>*.s1.luan.software</b>). Assuming your directory is <b>src</b> and you will use the password <b>secret</b>, do the following from the command line: + +<pre> + luan luan:host/push.luan bob.s1.luan.software secret src +</pre> + +<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> + +<p>Hopefully this short tutorial gave you an idea of how to use Luan to make a website.</p> + + </div> + </body> +</html> +<% +end