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=head1 NAME |
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A3C = AAAC; AAA from "Authentication, Authorization and Accounting" and C from "CARNet". |
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=head1 DESCRIPTION |
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This page describes general idea about A3C application and current status of implementation. |
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Opinions should be attributed to Dobrica Pavlinusic, and not other developers :-) |
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It's supposed to convey a story which is coherent enough for new developer |
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to join into project. Most of other documentation is more useful when |
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developing and looking into code usage (if it's not documented and tested, |
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it doesn't exist) but this part is delivered as pure POD for reading pleasure. |
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=head1 Models |
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Models in Jifty are at perl level objects (with validation and |
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canonicalization) and tables in database. |
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For a start, we implement some magic documented in L<A3C::Record> on records |
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(rows in database). |
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Then, we need to mungle data without re-thinking SQL queries which would |
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produce same results, so there is L<A3C::SQL> which produce objects that |
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look like L<Jifty::Collection>s, but aren't. This allows us to switch into |
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SQL in views if needed. |
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This method is not perfect, and shouldn't be used instead of Jifty models |
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just to write SQL because it doesn't do any permission checking. However, |
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it's a huge help for complex C<GROUP BY> and C<JOIN> queries which are hard |
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to express using L<Jifty::DBI>. |
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If we needed to generate those queries from within program (from user data, |
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for example) something like L<Fey::SQL> would be much better tool. |
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=head1 LDAP |
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Implement LDAP entry and edit interface (interesting problem since most |
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entries can have multiple values which doesn't map nicely to relational |
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schema). |
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This task can be broken down into following parts: |
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=head2 Multiple values |
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When creating records with ARRAY values L<A3C::Record/create> |
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joins values with magic marker between them to make rest of Jifty happy. |
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Plan is to use full-text search engine to search over data anyway, so this |
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is not serious limitation. If needed, something like bitmap indexes could be |
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used at database level to expose those values for filtering. For joins we |
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would probably need separate materialized many-many tables which could be |
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created more-or-less automatically in L<A3C::Record>. |
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=head2 Import data from existing LDAP server |
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C<bin/import-ldap.pl> has embedded documentation and uses L<A3C::LDAP> |
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L<http://a3c.skole.hr/ldap/> is user interface to L<A3C::View::LDAP> and |
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L<A3C::Action::SyncOrganization> |
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=head2 Query existing LDAP server |
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Since we are creating local copy of data, we need easy way to ask master |
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LDAP server for data. L<A3C::LDAP> provides way to query LDAP and receive |
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something similar enough to L<Jifty::Collection> so that L<A3C::View>s |
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doesn't have to be edited to switch from Jifty models to LDAP |
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data. |
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=head2 Create new entries and edit existing ones |
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We are in the middle of migration from (generic) L<A3C::Model::Person> and |
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L<A3C::Model::Organization> to our custom L<A3C::Model::hrEduOrg> and |
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L<A3C::Model::hrEduPerson> |
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Most views I guess, will be implemented by sub-classing L<Jifty::View::Declare::CRUD>. |
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Right now L<A3C::View::Organization> is such implementation. |
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Planned C<A3C::View::hrEduPerson> will implement another such view, and I |
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hope to see some kind of code reuse there (which should probably move to |
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C<Jifty::Plugin::TableCRUD>). |
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=head2 Virtual LDAP server to publish data |
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This part is in planning stage, and it will probably be based on L<Net::LDAP::Server>. |
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=head1 Existing LDAP schema |
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First, we needed a clever way to import existing LDAP schema into Jifty. So, |
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C<bin/ldap2model.pl> helper was created to handle that. |
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Some entries in LDAP schema have fixed list of attributed, and L<A3C::AAIEduHr> |
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implements fetcher (with cache) for that data. |
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=head1 Legacy portal integration |
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=head2 Parse PHP config files |
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Configuration files in PHP is only place in which part of portal |
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configuration is specified. To handle it in A3C, we use |
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L<A3C::Model::StrixInstance> which aggregates all instance data. Parser is |
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implemented by L<A3C::PHP> |
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=head2 Connect to remote database |
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Implemented in two different ways: |
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=head3 Direct SQL execution |
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L<A3C::Action::StrixSQL> and interface as L<A3C::View::Strix/sql>. |
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=head3 Fetching data hashes |
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C<Strix> (which doesn't link well from on-line documentation so you will |
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have to take a look in C<lib/Strix.pm>) implements pure DBI code (ported |
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from php) to access data directly. Keep in mind that this data have to be |
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cached for any reasonable performance. On the other hand, data can be |
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structured usefully, for example trees are structured in useful way for |
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direct output to JSON. |
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If tree has C<class> key, it can be set to C<error> so that we can mark |
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errors in data using same CSS class in views. This might be useful convention. |
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I prefer to keep this file documented up to level that make it's usage from Jifty and |
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C<t/50-strix.t> makes sense, but not more than that. |
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=head1 HTML |
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We don't generate HTML using templates. In fact, all HTML is encoded in perl |
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code using L<Template::Declare>. This allows easy generation of valid HTML, |
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high-level templates which are perl code and easy skinning using CSS. |
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C<share/web/static/css/app.css> is used to store application specific CSS. |
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It should probably be split into several files (Jifty will concatenate them |
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for us anyway) for easier maintenance, probably by same logic as view names |
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to skip additional step of mapping when human are watching into code. |
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In long run, this should allow us to refactor templates at code level and |
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create different re-usable widgets which brings us to following topic... |
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=head1 AJAX |
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Jifty's way of AJAX are L<Jifty::Manual::PageRegions>. |
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=head2 Strix navigation |
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L<http://a3c.skole.hr/strix/navigation> |
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For now, we have implementation of two-level select which is in sync with |
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instance clipboard (implemented by L<A3C::Model::StrixInstanceSelection> and |
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L<A3C::View::Strix> and L<A3C::Action::StrixSelectSite>. This is |
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good candidate to refactor into reusable widget on it's own. |
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=head1 BUGS |
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Many probably, documented in C<TODO> which is also useful for quick overview |
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what changed between versions if svn commit log is too detailed although |
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first line of commit message might be good summary of each individual |
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change. |