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