Most PGF web API commands that produce linearizations now accept an
unlexer parameter. Possible values are "text", "code" and "mixed".
The web service now include Date and Last-Modified headers in the HTTP,
responses. This means that browsers can treat responses as static content and
cache them, so it becomes less critical to cache parse results in the server.
Also did some cleanup in PGFService.hs, e.g. removed a couple of functions
that can now be imported from PGF.Lexing instead.
PGF service requests are stateless and can run in parallel, but some other
requests handled by the server are not and might even change the current
working directory temporarily, and this affects all threads, so it is
important that the PGF service requests access PGF files by absolute paths.
If the C run-time library is compiled and installed on your system, you can now
do 'cabal configure -fc-runtime' to get the following extras:
+ The haskell binding to the C run-time library will be included in the
PGF library (so you can import it in Haskell applications).
Documentation on the new modules will be included when you run
'cabal haddock'.
+ The new command 'pgf-shell', implemented on top of haskell binding to
the C run-time system.
+ Three new commands in the web API: c-parse, c-linearize and
c-translate. Their interfaces are similar to the corresponding commands
without the "c-" prefix, but they should be considered preliminary.
+ Eliminated vairous ad-hoc coersion functions between specific monads
(IO, Err, IOE, Check) in favor of more general lifting functions
(liftIO, liftErr).
+ Generalized many basic monadic operations from specific monads to
arbitrary monads in the appropriate class (MonadIO and/or ErrorMonad),
thereby completely eliminating the need for lifting functions in lots
of places.
This can be considered a small step forward towards a cleaner
compiler API and more malleable compiler code in general.
When a browser requests a URL that refers to a directory, web server usually
redirect the browser to the same URL with a trailing '/' added, if one was not
already present. This is to prevent relative links in the returned document
from being interpreted relative to the parent directory instead of the current
document. This type of redirection was missing in gf -server.
By adding a header
Access-Control-Allow-Origin: *
to the HTTP responses, web browsers are informed that it is OK to call the
services from web pages hosted on other sites.
This is apparently supported in most modern browsers, so it should no longer
be necessary to resort to JSONP.
See https://developer.mozilla.org/en-US/docs/HTTP/Access_control_CORS
The package network-2.4.1.1 thoughlessly introduced a backward incompatible
change to the function Network.URI.unEscapeString, see
f2168b1f89
This also affects the function Network.Shed.Httpd.queryToArguments, which is
used in GFServer.hs.
To remain compatible with older and newer versions of the network package,
we need to stay clear of queryToArguments and unEscapeString. A replacement
function has been added to server/URLEncoding.hs.
+ The restrictions on arbitrary IO when GF is running in restricted mode is now
enforced in the types.
+ This hopefully also solves an intermittent problem when accessing the GF
shell through the web API provided by gf -server. This was visible in the
Simple Translation Tool and probably caused by some low-level bug in the
GHC IO libraries.
+ More restrictive limits on which file paths can be downloaded and removed.
+ Add more extensions to the list of file types that may be removed. In
particular, allow documents created by simple translation tool to be removed.
This is an experimental feature. It requires server support for parsing and is
thus not available while offline, unlike most other editing functionality.
If there is an error in the grammar, the error message is shown below the
grammar instead.
Also: GFServer.hs now returns compiler output in a JSON structure instead of
as a HTML page.
The link to the minibar (or compiler errors) are now shown below the grammar
on the same page. If you go to the minibar, you only have to press the back
button once to get back to the editor.
Also some output formatting changes in GFServer.hs.
The grammar that the user is currently working is now the one shown initially
in minibar, instead of the first grammar in alphabetical order.
Also GFServer.hs now removes absolute paths to the grammar files on the server in error messages from GF returned to to gfse.
+ Avoid looping if it is not possible to create a new server directory.
+ Work on FastCGI support using the direct-fastcgi package (commented out
for now because of buggy behavior).
"gf -server" mode now contains everything needed to run the minibar and
the grammar editor (including example-based grammar writing).
The Setup.hs script installs the required files where gf -server can find them.
These files have been moved to a new directory: src/www.
The separate server program pgf-http is now obsolete.
"gf -server" mode now includes PGF service and the services to support
example-based grammar writing. (But gf -server is not quite ready to replace
pgf-http yet...)
Also bumped GF version number to 3.2.10-darcs
The command "gf -server" now starts a simple HTTP server on port 41295,
providing a simple web API to the GF compiler. It currently support the
follwing operations:
* creating new temporary directories for grammar uploads,
* uploading grammars files for use in the GF shell,
* executing GF shell commands, and
* accessing static files.
This means that GF now depends on some additional networking related packages,
but they should be available and easy to install on all platforms. There is
also a new configuration flag "server" in gf.cabal, so GF will be compiled
without support for server mode if the extra packages are unavailable.
Note that running gf -server while connected to the internet can be a security
risk. To prevent unauthorized access to the rest of the system, it is
advisable to run the server in GF_RESTRICTED mode and as a user with suitably
restricted file permissions.
