Orbit
MVC for Lua Web Development

Reference Manual

This is a short reference of all of Orbit's (and Orbit apps) methods.

Module orbit

orbit.new([app]) - creates a new Orbit application, returning it (as a module). If app is a string this is the application's name, and sets field _NAME. If app is a table it is used instead of a fresh table. This means you can pass orbit.new to the module function

orbit.htmlify(func[, func...]) - modifies the environment of func to include functions that generate HTML

Orbit apps

app.run(wsapi_env) - WSAPI entry point for application, generated by Orbit

app.real_path - the root of the application in the filesystem, defaults to the path inferred by WSAPI launchers (wsapi.app\_path), but can be overridden

app.mapper - mapper used by app:model, defaults to an instance of orbit.model, but can be overridden

app.not_found - default handler, sends a 404 response to the client, can be overridden. The handler receives a web object

app.server_error - error handler, sends a 500 response with stack trace to the client, can be overridden. The handler receives a web object

app:dispatch_get(func, patt[, patt...]) - installs func as a GET handler for the patterns patt. func receives a web object and the captures; this handler should return the contents of the response or app.reparse if you want to hand control back to the dispatcher and let it continue matching;

app:dispatch_post(func, patt[, patt...]) - installs func as a POST handler for the patterns patt. func receives a web object and the captures; this handler should return the contents of the response or app.reparse if you want to hand control back to the dispatcher and let it continue matching;

app:dispatch_put(func, patt[, patt...]) - installs func as a PUT handler for the patterns patt. func receives a web object and the captures; this handler should return the contents of the response or app.reparse if you want to hand control back to the dispatcher and let it continue matching;

app:dispatch_delete(func, patt[, patt...]) - installs func as a DELETE handler for the patterns patt. func receives a web object and the captures; this handler should return the contents of the response or app.reparse if you want to hand control back to the dispatcher and let it continue matching;

app:dispatch_wsapi(func, patt[, patt...]) - installs func as a WSAPI handler for the patterns patt. func receives the unmodified WSAPI environment

app:dispatch_static(patt[, patt...]) - installs a static files handler for the patterns patt. This handler assumes the PATH_INFO is a file relative to app.real_path and sends it to the client. The MIME type is detected from the extension (default application/octec-stream)

app:serve_static(web, filename) - returns the content of file filename (which can be anywhere in the filesystem), while setting the appropriate headers with the file's MIME type

app:htmlify(patt[, patt...]) - same as orbit.htmlify, but changes all of the app's module functions that match the patterns patt

app:model(...) - calls app.mapper:new(...), so the behaviour depends on the mapper you are using

web methods

The web objects inherit the functions of module wsapi.util as methods.

web.status - status to be sent to server (default: "200 Ok")

web.headers - headers to be sent to server, a Lua table (default has Content-Type as text/html)

web.response - body to send to the server (default is blank)

web.vars - original WSAPI environment

web.prefix - app's prefix (if set in the app's module) or SCRIPT_NAME

web.suffix - app's suffix (if set in the app's module)

web.real_path - location of app in filesystem, taken from wsapi_env.APP_PATH, or app's module real_path, or "."

web.doc_root, web.path_info, web.script_name, web.path_translated, web.method - server's document root, PATH_INFO, SCRIPT_NAME, PATH_TRANSLATED, and REQUEST_METHOD (converted to lowercase)

web.GET, web.POST - GET and POST variables

web.input - union of web.GET and web.POST

web.cookies - cookies sent by the browser

web:set_cookie(name, value) - sets a cookie to be sent back to browser

web:delete_cookie(name) - deletes a cookie

web:redirect(url) - sets status and headers to redirect to url

web:link(part, [params]) - creates intra-app link, using web.prefix and web.suffix, and encoding params as a query string

web:static_link(part) - if app's entry point is a script, instead of path, creates a link to the app's vpath (e.g. if app.prefix is /foo/app.ws creates a link in /foo/part), otherwise same as web:link

web:empty(s) - returns true if s is nil or an empty string (zero or more spaces)

web:content_type(s) - sets the content type of the reponse to s

web:empty_param(name) - returns true if input parameter name is empty (as web:empty)

web:page(name, [env]) - loads and renders Orbit page called name. If name starts with / it's relative to the document root, otherwise it's relative to the app's path. Returns rendered page. env is an optional environment with extra variables.

web:page_inline(contents, [env]) - renders an inline Orbit page

Module orbit.cache

orbit.cache.new(app, [base_path]) - creates a page cache for app, either in memory or at the filesystem path base_path (not relative to the app's path!), returns the cache object

a_cache(handler) - caches handler, returning a new handler; uses the PATH_INFO as a key to the cache

a_cache:get(key) - gets value stored in key; usually not used, use the previous function instead

a_cache:set(key, val) - stores a value in the cache; use a_cache(handler) to encapsulate this behaviour

a_cache:invalidate(key) - invalidates a cache value

a_cache:nuke() - clears the cache

Module orbit.model

orbit.model.new([table_prefix], [conn], [driver], [logging]) - creates a new ORM mapper. table_prefix (default "") is a string added to the start of model names to get table names; conn is the database connection (can be set later); driver is the kind of database (currently "sqlite3", the default, and "mysql"); logging sets whether you want logging of all queries to io.stderr. Returns a mapper instance, and all the parameters can be set after this instance is created (via a_mapper.table_prefix, a_mapper.conn, a_mapper.driver, and a_mapper.logging)

orbit.model.recycle(conn_builder, timeout) - creates a connection using conn_builder, a function that takes no arguments, and wraps it so a new connection is automatically reopened every timeout seconds

a_mapper:new(name, [tab]) - creates a new model object; name is used together with a_mapper.table_prefix to form the DB table's name; fields and types are introspected from the table. tab is an optional table that is used as the basis for the model object if present

a_model.model - the mapper for this model

a_model.name, a_model.table_name - the name of the model and its backing table

a_model.driver - the DB driver used

a_model.meta - metainformation about the model, introspected from the table

a_model:find(id) - finds and returns the instance of the model with the passed id (keyed using the id column of the table (must be numeric)

a_model:find_first(condition, args) - finds and returns the first instance of the model that matches condition; args can determine the order (args.order), specify which fields should be returned (args.fields, default is all of them), and inject fields from other tables (args.inject)

Example: books:find_first("author = ? and year_pub > ?", { "John Doe", 1995, order = "year_pub asc" })

a_model:find_all(condition, args) - finds and returns all instances of the model that matches condition; args can determine the order (args.order), specify which fields should be returned (args.fields, default is all of them), limit the number of returned rows (args.count), return only distinct rows (args.distinct), and inject fields from other tables (args.inject)

Example: books:find_all("author = ? and year_pub > ?", { "John Doe", 1995, order = "year_pub asc", count = 5, fields = { "id", "title" } })

a_model:new([tab]) - creates a fresh instance of the model, optionally using tab as initial values

a_model:find_by_xxx(args) - finds and returns the first instance of the model building the condition from the method name, a la Rails' ActiveRecord; args works the same way as in find_first, above

a_model:find_all_by_xxx(args) - finds and returns all instances of the model building the condition from the method name, a la Rails' ActiveRecord; args works the same way as in find_all, above

Example: books:find_all_by_author_or_author{ "John Doe", "Jane Doe", order = "year_pub asc" }

an_instance:save([force_insert]) - saves an instance to the DB, commiting changes or creating the backing record if the instance is new; if force_insert is true always do an insert instead of an update

If there's a row called created_at this row is set to the creation date of the record; if there's a row called updated_at this row is set to the last update's date.

an_instance:delete() - deletes an instance from the DB

Module orbit.routes

This module has a single function, R, and you can also call the module itself. This function takes a PATH_INFO pattern where the path segments (the parts of the path separated by / or .) can be named parameters (:name), splats (*), optional parameters (?:name?), or literals, and returns a pattern.

A pattern is an object with two methods:

patt:match(str) - tries to match str and returns a hash of named parameters; splats are returned in a splat array inside this hash.

patt:build(params) - builds the original pattern string from a hash of named parameters

Some examples of patterns, what they match, and the parameter hashes:

  • '/foo', matches '/foo', empty hash
  • '/foo/:bar/baz' matches '/foo/orbit/baz' or '/foo/xxx.yyy/baz' with hashes { bar = 'orbit' } and { bar = 'xxx.yyy' }
  • '/:name.:ext' matches '/xxx.yyy' or '/filename.ext' with hashes { name = 'xxx', ext = 'yyy' } and { name = 'filename', ext = 'ext' }
  • '//foo/' matches '/bar/foo' or '/bar/foo/bling/baz/boom' with hashes { splat = { 'bar' } } and { splat = { 'bar', 'bling/baz/boom' } }
  • '/?:foo?/?:bar?' matches '/' or '/orbit' or '/orbit/routes' with hashes {} and { foo = 'orbit' } and { foo = 'orbit', bar = 'routes' }

And several more, see test/test_routes.lua for a comprehensive test suite.

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