2013-10-18 23:57:59 +08:00
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# Mongoose Lua Server Pages
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2014-01-06 21:08:39 +08:00
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Pre-built Windows and Mac mongoose binaries support Lua Server Pages
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functionality.
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That means it is possible to write PHP-like scripts with mongoose
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2013-10-18 23:57:59 +08:00
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using Lua programming language instead of PHP. Lua is known
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for it's speed and small size. Mongoose uses Lua version 5.2.1, the
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documentation for it can be found at
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[Lua 5.2 reference manual](http://www.lua.org/manual/5.2/).
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2014-01-06 21:08:39 +08:00
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To create a Lua Page, make a file that is called `<something>.lp`. For example,
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let's say it is going to be `my_page.lp`. It is important to have a file
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name that ends up with `.lp`, cause this is the way mongoose recognises
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Lua Page file. The contents of the file, just like
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with PHP, is HTML with embedded Lua code. Lua code must be enclosed within
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`<? ?>` blocks, and can appear anywhere on the page.
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2013-10-18 23:57:59 +08:00
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2014-01-06 21:08:39 +08:00
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Mongoose does not send HTTP headers for Lua pages. Therefore,
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every Lua Page must begin with HTTP status line and headers, like this:
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<? mg.write('HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n') ?>
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<html><body>
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<span>Today is:</span> <? mg.write(os.date("%A")) ?>
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</body></html>
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2013-10-18 23:57:59 +08:00
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Note that this example uses function `mg.write()`, which prints data to the
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web page. Using function `mg.write()` is the way to generate web content from
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inside Lua code. In addition to `mg.write()`, all standard library functions
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2014-01-06 21:08:39 +08:00
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are accessible from the Lua code (please check reference manual for details).
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Information about the request is available in `mg.request_info` object.
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I contains request method, all headers, etcetera. Please refer to
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2013-10-18 23:57:59 +08:00
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`struct mg_request_info` definition in
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[mongoose.h](https://github.com/cesanta/mongoose/blob/master/mongoose.h)
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to see what is available in `mg.request_info`. Also,
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2013-10-18 23:57:59 +08:00
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[page.lp](https://github.com/cesanta/mongoose/blob/master/test/page.lp) and
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[prime_numbers.lp](https://github.com/cesanta/mongoose/blob/master/examples/lua/prime_numbers.lp)
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2014-01-06 21:08:39 +08:00
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contain some example code that uses `request_info` and other functions,
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like form submission.
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2013-10-18 23:57:59 +08:00
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Mongoose exports the following to the Lua server page:
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mg.write(str) -- writes string to the client
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mg.onerror(msg) -- error handler, can be overridden
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mg.request_info -- a table with request information
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sqlite3 -- Sqlite3 interface
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2013-10-18 23:57:59 +08:00
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2014-01-06 21:08:39 +08:00
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slite3 functions are documented at [lua.sqlite.org](http://lua.sqlite.org/),
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and usage example is at
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[page.lp](https://github.com/cesanta/mongoose/blob/master/test/page.lp).
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2013-10-18 23:57:59 +08:00
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2014-01-06 21:08:39 +08:00
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Using Lua scripting it is easy to emulate SSI functionality. For example,
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to include the content of another file, one can write:
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2013-10-18 23:57:59 +08:00
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2014-01-06 21:08:39 +08:00
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<? mg.write(io.open('MY_FILE.TXT'):read('*all')) ?>
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2013-10-18 23:57:59 +08:00
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2014-01-06 21:08:39 +08:00
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To serve a Lua Page, mongoose creates Lua context. That context is used for
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all Lua blocks within the page. That means, all Lua blocks on the same page
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share the same context. If one block defines a variable, for example, that
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variable is visible in the block that follows.
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