UnknownFileTypeServlet

Servlet factory for unknown file types.

class UnknownFileTypeServlet.UnknownFileTypeServlet(application)

Bases: HTTPServlet, Configurable

Servlet for unknown file types.

Normally this class is just a “private” utility class for Webware’s purposes. However, you may find it useful to subclass on occasion, such as when the server side file path is determined by something other than a direct correlation to the URL. Here is such an example:

from UnknownFileTypeServlet import UnknownFileTypeServlet import os

class Image(UnknownFileTypeServlet):

imageDir = ‘/var/images’

def filename(self, trans):

filename = trans.request().field(‘i’) filename = os.path.join(self.imageDir, filename) return filename

__init__(application)

Subclasses must invoke super.

awake(transaction)

Send the awake message.

This message is sent to all objects that participate in the request-response cycle in a top-down fashion, prior to respond(). Subclasses must invoke super.

canBeReused()

Returns whether a single servlet instance can be reused.

The default is True, but subclasses con override to return False. Keep in mind that performance may seriously be degraded if instances can’t be reused. Also, there’s no known good reasons not to reuse an instance. Remember the awake() and sleep() methods are invoked for every transaction. But just in case, your servlet can refuse to be reused.

canBeThreaded()

Return whether the servlet can be multithreaded.

This value should not change during the lifetime of the object. The default implementation returns False. Note: This is not currently used.

close()
commandLineConfig()

Return the settings that came from the command-line.

These settings come via addCommandLineSetting().

config()

Return the configuration of the object as a dictionary.

This is a combination of defaultConfig() and userConfig(). This method caches the config.

configFilename()

Return the full name of the user config file.

Users can override the configuration by this config file. Subclasses must override to specify a name. Returning None is valid, in which case no user config file will be loaded.

configName()

Return the name of the configuration file without the extension.

This is the portion of the config file name before the ‘.config’. This is used on the command-line.

configReplacementValues()

Return a dictionary for substitutions in the config file.

This must be a dictionary suitable for use with “string % dict” that should be used on the text in the config file. If an empty dictionary (or None) is returned, then no substitution will be attempted.

defaultConfig()

Get the default config.

Taken from Application’s ‘UnknownFileTypes’ default setting.

filename(trans)

Return the filename to be served.

A subclass could override this in order to serve files from other disk locations based on some logic.

hasSetting(name)

Check whether a configuration setting has been changed.

lastModified(trans)

Get time of last modification.

Return this object’s Last-Modified time (as a float), or None (meaning don’t know or not applicable).

log(message)

Log a message.

This can be invoked to print messages concerning the servlet. This is often used by self to relay important information back to developers.

name()

Return the name which is simple the name of the class.

Subclasses should not override this method. It is used for logging and debugging.

static notImplemented(trans)
open()
printConfig(dest=None)

Print the configuration to the given destination.

The default destination is stdout. A fixed with font is assumed for aligning the values to start at the same column.

static readConfig(filename)

Read the configuration from the file with the given name.

Raises an UIError if the configuration cannot be read.

This implementation assumes the file is stored in utf-8 encoding with possible BOM at the start, but also tries to read as latin-1 if it cannot be decoded as utf-8. Subclasses can override this behavior.

static redirectSansScript(trans)

Redirect to web server.

Sends a redirect to a URL that doesn’t contain the script name. Under the right configuration, this will cause the web server to then be responsible for the URL rather than the WSGI server. Keep in mind that links off the target page will not include the script name in the URL.

respond(transaction)

Respond to a request.

Invokes the appropriate respondToSomething() method depending on the type of request (e.g., GET, POST, PUT, …).

respondToGet(trans)

Respond to GET request.

Responds to the transaction by invoking self.foo() for foo is specified by the ‘Technique’ setting.

respondToHead(trans)

Respond to GET request.

Responds to the transaction by invoking self.foo() for foo is specified by the ‘Technique’ setting.

respondToPost(trans)

Respond to POST request.

Invoke self.respondToGet().

Since posts are usually accompanied by data, this might not be the best policy. However, a POST would most likely be for a CGI, which currently no one is mixing in with their Webware-based web sites.

runMethodForTransaction(transaction, method, *args, **kw)
static runTransaction(transaction)
serveContent(trans)
serverSidePath(path=None)

Return the filesystem path of the page on the server.

setFactory(factory)
setSetting(name, value)

Set a particular configuration setting.

setting(name, default=<class 'MiscUtils.NoDefault'>)

Return the value of a particular setting in the configuration.

shouldCacheContent()

Return whether the content should be cached or not.

Returns a boolean that controls whether or not the content served through this servlet is cached. The default behavior is to return the CacheContent setting. Subclasses may override to always True or False, or incorporate some other logic.

sleep(transaction)

Send the sleep message.

userConfig()

Get the user config.

Taken from Application’s ‘UnknownFileTypes’ user setting.

static validTechniques()
class UnknownFileTypeServlet.UnknownFileTypeServletFactory(application)

Bases: ServletFactory

The servlet factory for unknown file types.

I.e. all files other than .py, .psp and the other types we support.

__init__(application)

Create servlet factory.

Stores a reference to the application in self._app, because subclasses may or may not need to talk back to the application to do their work.

extensions()

Return a list of extensions that match this handler.

Extensions should include the dot. An empty string indicates a file with no extension and is a valid value. The extension ‘.*’ is a special case that is looked for a URL’s extension doesn’t match anything.

flushCache()

Flush the servlet cache and start fresh.

Servlets that are currently in the wild may find their way back into the cache (this may be a problem).

importAsPackage(transaction, serverSidePathToImport)

Import requested module.

Imports the module at the given path in the proper package/subpackage for the current request. For example, if the transaction has the URL http://localhost/Webware/MyContextDirectory/MySubdirectory/MyPage and path = ‘some/random/path/MyModule.py’ and the context is configured to have the name ‘MyContext’ then this function imports the module at that path as MyContext.MySubdirectory.MyModule . Note that the context name may differ from the name of the directory containing the context, even though they are usually the same by convention.

Note that the module imported may have a different name from the servlet name specified in the URL. This is used in PSP.

loadClass(transaction, path)

Load the appropriate class.

Given a transaction and a path, load the class for creating these servlets. Caching, pooling, and threadsafeness are all handled by servletForTransaction. This method is not expected to be threadsafe.

name()

Return the name of the factory.

This is a convenience for the class name.

returnServlet(servlet)

Return servlet to the pool.

Called by Servlet.close(), which returns the servlet to the servlet pool if necessary.

servletForTransaction(transaction)

Return a new servlet that will handle the transaction.

This method handles caching, and will call loadClass(trans, filepath) if no cache is found. Caching is generally controlled by servlets with the canBeReused() and canBeThreaded() methods.

uniqueness()

Return uniqueness type.

Returns a string to indicate the uniqueness of the ServletFactory’s servlets. The Application needs to know if the servlets are unique per file, per extension or per application.

Return values are ‘file’, ‘extension’ and ‘application’.

NOTE: Application so far only supports ‘file’ uniqueness.