1: This is a pilot release of the NSDL-LONCAPA Gateway.
3: The goal
5: Implement a metadata exchange of resources from
6: NSDL (http://www.smete.org) to LON-CAPA (http://www.lon-capa.org)
7: and vice versa.
9: More information is in the doc/ directory.
11: What's new
13: For a history of this software, you should work through
14: the CVS repository.
16: export CVSROOT=:pserver:USERNAME@install.lon-capa.org:/home/cvs
17: cvs login
18: cvs co nsdl
20: How to build and install
23: cd nsdl/build
24: make build
25: make install
27: Important files
29: To get a good overview on the metadata conversion, I recommend
30: you look at the nsdl/prototypes/metadata_convert.pl script
31: (perldoc -f metadata_convert.pl). Among other things, this
32: provides a list regarding the crosswalk possibilities of
33: LON-CAPA to&from IEEE-LOM and LON-CAPA to&from Dublin Core.
35: Currenty, the four stylesheets for carrying out the metadata conversion are:
36: * nsdl/lib/stylesheets/dcnsdl_to_loncapa.xsl
37: * nsdl/lib/stylesheets/lomnsdl_to_loncapa.xsl
38: * nsdl/lib/stylesheets/loncapa_to_dcnsdl.xsl
39: * nsdl/lib/stylesheets/loncapa_to_lomnsdl.xsl
41: The Apache web handler modules are defined in the directory:
42: nsdl/lib/perl/Apache/ .
44: The Apache configuration file (see below also) is
45: nsdl/conf/nsdl.conf .
47: The source-to-target information is defined by nsdl/build/gatewayfiles.lpml
48: (an XML file defines how the software is "rendered" onto the system).
49: gatewayfiles.lpml is used in many locations inside nsdl/build/Makefile.
51: And, there are other files.
53: System requirements
55: * Apache and mod_perl
56: * Graham Barr's TimeDate module (http://search.cpan.org/search?dist=TimeDate)
57: * XML::Xalan perl module (http://search.cpan.org/search?dist=XML-Xalan)
59: To configure your machine, you will need to add the following
60: line to your /etc/httpd/conf/httpd.conf file.
62: Include conf/nsdl.conf
64: (You will then need to restart your web server;
65: /etc/rc.d/init.d/httpd restart)
69: This is a pilot effort. The goal was to enact a reasonable
70: solution and directly uncover difficult issues.
72: Here are some of the remaining issues
73: * ISSUE: User authentication
74: PROBLEM: users are crossing domains, so browser-cookie validation can't work
75: SUGGESTED SOLUTIONS: should require a GPG public key and/or
76: servers should communicate to coordinate passing of user
77: and/or some kind of proxy or central verification system
78: * ISSUE: Imperfect metadata cross-walking
79: PROBLEM: There are a range of imperfect mappings between Dublin Core and
80: LON-CAPA metadata fields as well as between IEEE LOM and LON-CAPA
81: metadata fields.
82: SUGGESTED SOLUTIONS: Improve the LON-CAPA metadata that is collected and
83: place more importance on the exhaustive IEEE LOM
84: standard rather than the weaker Dublin Core standard.
85: In the future, to get to Dublin Core, it might make
86: sense to first convert LON-CAPA to IEEE LOM and *then*
87: go to the Dublin Core metadata standard.
88: * ISSUE: Set hierarchies
89: PROBLEM: Asking for ListIdentifiers from LON-CAPA will return a really long
90: list that represents a "jumbled" repository. Currently,
91: ListIdentifiers, ListRecords, etc return error messages--
92: we do not yet support set hierarchy results.
93: SUGGESTED SOLUTIONS: authors should be able to nominate their records
94: for being part of a meaningful collection of academic
95: resources; thus multiple OAI-distributed metadata sets
96: would actually be contained within LON-CAPA
97: * ISSUE: Code thoroughness
98: PROBLEM: Limited time. I had limited time (100 hours) to enact a gateway.
99: SUGGESTED SOLUTIONS: Invest more time. The API and documentation
100: could be a better match for what is implemented
101: and vice versa.
102: * ISSUE: Making SMETE available to LON-CAPA
103: PROBLEM: Ummm... I thought SMETE supported OAI. The only interface I find
104: is enriched HTML forms.
105: SUGGESTED SOLUTIONS: SMETE should support OAI or some exporting of XML files
106: in Dublin Core or IEEE LOM or whatever they are using.
110: Scott Harrison, 2002