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> > | Metadata RepositoryOn this page:
Motivation
Basics
It's optionalThe repository being for a large site having hundreds or thousands of webs, its use is optional. It's activated only if the site owner explicitly turns on the metadata repository.
Structure
ExamplesHere's how a metadata repository would be used by federated TWiki sites.
Federation of sitesLet's assume the following federation of TWiki sites.
Web adminsIf there are many webs, it may not be easy to get hold of people responsible for a web. So it's handy if all webs have their admins clearly defined. Given that, let's assume we define admins for each web and store as a part of web metadata.
Site metadata and web metadata fieldsThe following fields are needed in a site metadata record to implement the federation shown above.
And the following fields in the web metadata.
How to get and put data - overview
mdrepo script from command line
Go to the bin directory then you can use the
mdrepo show TABLE RECORD_IDShows the specified record of the specified table. Example: $ ./mdrepo show sites am am datadir=/d/twiki/data pubdir=/d/twiki/pub server=strawman
mdrepo list TABLEShows all the records of the specified table. Example: $ ./mdrepo list sites am datadir=/d/twiki/data pubdir=/d/twiki/pub server=strawman as datadir=/share/twiki/data pubdir=/share/twiki/pub server=tinman eu datadir=/var/twiki/data pubdir=/var/twiki/pub server=woodenman
mdrepo add TABLE RECORD_ID FIELD_NAME=VALUE ...Adds a new record. It returns nothing. If the specified record already exists, it complains. Example: $ ./mdrepo add webs WebFour admin=HofstadterGroup master=am
mdrepo updt TABLE RECORD_ID FIELD_NAME=VALUE ...Update an existing record. It returns nothing. If the specified record does not exist, it complains. Example: $ ./mdrepo updt webs WebFour admin=GardnerGroup master=am
mdrepo del TABLE RECORD_IDDeletes an existing record. It returns nothing. If the specified record does not exist, it complains. Example: $ ./mdrepo del webs WebFour admin=GardnerGroup master=am
mdrep load TABLE FILELoads records to the specified table from the specified file. The file content is in the same format as the list command's output. Nonexistent records are created. Existing records are updated. Example: $ ./mdrepo load /var/tmp/temp-webs
mdrepo rset TABLEMakes the specified table empty. It returns nothing. Example: $ ./mdrepo rset sites
mdrepo script from browser
RestrictionsCompared with command line use, browser use of mdrepo script is restricted for risk mitigation.
URL parameters
The table and the record ID are specified by the Field values are specified by parameters of the =__FIELD_NAME format. For example, submitting the following form has the same effect as the command line shown further below. <form action="%SCRIPTURL%/mdrepo" method="post"> <input type="hidden" name="_add" value="add"/> <input type="hidden" name="_table" value="webs"/> <input type="hidden" name="_recid" value="WebFour"/> <input type="hidden" name="__admin" value="GardnerGroup"/> <input type="hidden" name="__master" value="am"/> <input type="submit"/>
$ ./mdrepo add webs WebFour admin=GardnerGroup master=am
OutputBy default, the script's output is in the text/plain MIME type. If the command succeeds, it returns nothing. When something goes wrong, an error message is returned.
If
ConfigurationTo turn on the metadata repository, you need to have the following three settings. $TWiki::cfg{Mdrepo}{Store} = 'DB_File'; $TWiki::cfg{Mdrepo}{Dir} = '/var/twiki/mdrepo'; $TWiki::cfg{Mdrepo}{Tables} = [qw(sites webs:b)];
By the following setting, each web required to have its metadata record. $TWiki::cfg{Mdrepo}{WebRecordRequired} = 1;For a large site having thousands of webs, this is handy for site management. Specifically this brings the following behaviors.
Audit trail
When the
updt , del , and rset commands put multiple log entries so that the previous values are recorded. Here's an example of log entries left by a updt operation.
| 2012-06-15 - 13:16 | guest | mdrepo | TemporaryTestWeb.TestTopic | cur sites am datadir=/d/twiki/data pubdir=/d/twiki/pub server=strawman | | | 2012-06-15 - 13:16 | guest | mdrepo | TemporaryTestWeb.TestTopic | updt sites am datadir=/d/twiki/dat pubdir=/d/twiki/pu server=strawma | |When the mdrepo script is used from a command line, the topic name on the log is always Main.WebHome.
Audit trail is there by default. In case you want to suppress it, you can do it by setting a false value to $TWiki::cfg{Log}{mdrepo} configuration preference.
Only for top level websFor practicality, web metadata is only for top level webs. More accurately, a subweb has the same web metadata as its parent. The reason is that site administration gets complicated if subwebs can have different web metadata. Related Topics: AdminDocumentationCategory, AutonomousWebs, ReadOnlyAndMirrorWebs, UsingMultipleDisks, UserMasquerading
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