public package Foswiki::Meta

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public package Foswiki::Meta

Objects of this class act as handles onto real store objects. An object of this class can represent the Foswiki root, a web, or a topic.

Meta objects interact with the store using only the methods of Foswiki::Store. The rest of the core should interact only with Meta objects; the only exception to this are the *Exists methods that are published by the store interface (and facaded by the Foswiki class).

A meta object exists in one of two states; either unloaded, in which case it is simply a lightweight handle to a store location, and loaded, in which case it acts as a portal onto the actual store content of a specific revision of the topic.

An unloaded object is constructed by the new constructor on this class, passing one to three parameters depending on whether the object represents the root, a web, or a topic.

A loaded object may be constructed by calling the load constructor, or a previously constructed object may be converted to 'loaded' state by calling loadVersion. Once an object is loaded with a specific revision, it cannot be reloaded.

Unloaded objects return undef from getLoadedRev, or the loaded revision otherwise.

An unloaded object can be populated through calls to text($text), put and putKeyed. Such an object can be saved using save() to create a new revision of the topic.

To the caller, a meta object carries two types of data. The first is the "plain text" of the topic, which is accessible through the text() method. The object also behaves as a hash of different types of meta-data (keyed on the type, such as 'FIELD' and 'FILEATTACHMENT').

Each entry in the hash is an array, where each entry in the array contains another hash of the key=value pairs, corresponding to a single meta-datum.

If there may be multiple entries of the same top-level type (i.e. for FIELD and FILEATTACHMENT) then the array has multiple entries. These types are referred to as "keyed" types. The array entries are keyed with the attribute 'name' which must be in each entry in the array.

For unkeyed types, the array has only one entry.

Pictorially,

• TOPICINFO
  • author => '...'
  • date => '...'
  • …
• FILEATTACHMENT
  • [0] = { name => 'a' … }
  • [1] = { name => 'b' … }
• FIELD
  • [0] = { name => 'c' … }
  • [1] = { name => 'd' … }

Implementor note: the _indices field gives a quick lookup into this structure; it is a hash of top-level types, each mapping to a hash indexed on the key name. For the above example, it looks like this:

• _indices => { FILEATTACHMENT => { a => 0, b => 1 }, FIELD => { c => 0, d => 1 } }

It is maintained on the fly by the methods of this module, which makes it important not to write new data directly into the structure, but always to go through the methods exported from here.

As required by the contract with Foswiki::Store, version numbers are required to be positive, non-zero integers. When passing in version numbers, 0, undef and ” are treated as referring to the latest (most recent) revision of the object. Version numbers are required to increase (later version numbers are greater than earlier) but are not required to be sequential.

IMPORTANT the methods on Foswiki::Meta do not check access permissions (other than haveAccess, obviously). This is a deliberate design decision, as these checks are expensive and many callers don't require them. For this reason, be very careful how you use Foswiki::Meta. Extension authors will almost always find the methods they want in Foswiki::Func, rather than in this class.

Since date indicates where functions or parameters have been added since the baseline of the API (Foswiki release 4.2.3). The date indicates the earliest date of a Foswiki release that will support that function or parameter.

Deprecated date indicates where a function or parameters has been deprecated. Deprecated functions will still work, though they should not be called in new plugins and should be replaced in older plugins as soon as possible. Deprecated parameters are simply ignored in Foswiki releases after date.

Until date indicates where a function or parameter has been removed. The date indicates the latest date at which Foswiki releases still supported the function or parameter.

PUBLIC %VALIDATE;

META:x validation. This hash maps from META: names to the type record registered by registerMETA. See registerMETA for more information on what these records contain.

_default is set on base meta-data types (those not added by Foswiki::Func::registerMETA) to differentiate the minimum required meta-data and that added by extensions.

StaticMethod registerMETA($name, %syntax)

Foswiki supports embedding meta-data into topics. For example,

%META:BOOK{title="Transit" author="Edmund Cooper" isbn="0-571-05724-1"}%

This meta-data is validated when it is read from the store. Meta-data that is not registered, or doesn't pass validation, is ignored. This function allows you to register a new META datum, passing the name in $name. %syntax contains information about the syntax and semantics of the tag.

The following entries are supported in %syntax

many=>1. By default meta-data are single valued i.e. can only occur once in a topic. If you require the meta-data to be repeated many times (like META:FIELD and META:ATTACHMENT) then you must set this option. For example, to declare a many-valued BOOK meta-data type:

registerMeta('BOOK', many => 1)

require=>[] is used to check that a list of named parameters are present on the tag. For example,

registerMETA('BOOK', require => [ 'title', 'author' ]);

can be used to check that both title and author are present.

allow=>[] lets you specify other optional parameters that are allowed on the tag. If you specify allow then the validation will fail if the tag contains any parameters that are not in the allow or require lists. If you don't specify allow then all parameters will be allowed.

require and allow only verify the presence of parameters, and not their values.

other=[] lets you declare other legal parameters, and is provided mainly to support the initialisation of DB schema. It it is like allow except that it doesn't imply any exclusion of META that contains unallowed params.

function=>\&fn causes the function fn to be called when the datum is encountered when reading a topic, passing in the name of the macro and the argument hash. The function must return a non-zero/undef value if the tag is acceptable, or 0 otherwise. For example:

registerMETA('BOOK', function => sub {
    my ($name, $args) = @_;
    # $name will be BOOK
    return isValidTitle($args->{title});
}

can be used to check that %META:BOOK{} contains a valid title.

Checks are cumulative, so if you:

registerMETA('BOOK',
    function => \&checkParameters,
    require => [ 'title' ],
    allow => [ 'author', 'isbn' ]);

then all these conditions will be tested. Note that require and allow are tested after function is called, to give the function a chance to rewrite the parameter list.

If no checker is registered for a META tag, then it will automatically be accepted into the topic meta-data.

alias=>'name' lets you set an alias for the datum that will be added to the query language. For example, alias=>'info' is used to alias 'META:TOPICINFO' in queries.

registerMeta('BOOK', alias => 'book', many => 1)

This lets you use syntax such as books[author='Anais Nin'] in queries. See QuerySearch for more on aliases.

ClassMethod new($session, $web, $topic [, $text])

• $session - a Foswiki object (e.g. $Foswiki::Plugins::SESSION)
• $web, $topic - the pathname of the object. If both are undef, this object is a handle for the root container. If $topic is undef, it is the handle to a web. Otherwise it's a handle to a topic.
• $text - optional raw text, which may include embedded meta-data. Will be deserialised to initialise the object. Only valid if $web and $topic are defined.

Construct a new, unloaded object. This method creates lightweight handles for store objects; the full content of the actual object will not be loaded. If you need to interact with the existing content of the stored object, use the load method to load the content.

ClassMethod new($prototype)

Construct a new, unloaded object, using the session, web and topic in the prototype object (which must be type Foswiki::Meta).

ClassMethod load($session, $web, $topic, $rev)

This constructor will load (or otherwise fetch) the meta-data for a named web/topic.

• $rev - revision to load. If undef, 0, ” or > max available rev, will load the latest rev. If the revision is in range but does not exist, then will return an unloaded meta object (getLoadedRev() will be undef)

This method is functionally identical to:

$this = Foswiki::Meta->new( $session, $web, $topic );
$this->loadVersion( $rev );

WARNING: see notes on revision numbers under getLoadedRev.

ObjectMethod load($rev) → $metaObject

Load an unloaded meta-data object with a given version of the data. Once loaded, the object is locked to that revision.

• $rev - revision to load. If undef, 0, ” or > max available rev, will load the latest rev. If the revision is in range but does not exist, then will return an unloaded meta object (getLoadedRev() will be undef)

WARNING: see notes on revision numbers under getLoadedRev

TODO: this is insane. load() can fail - but it will give you a seemingly fine Meta object anyway.

ObjectMethod unload()

Return the object to an unloaded state. This method should be used with the greatest of care, as it resets the load state of the object, which may have surprising effects on other code that shares the object.

ObjectMethod finish()

Clean up the object, releasing any memory stored in it. Make sure this gets called before an object you have created goes out of scope.

ObjectMethod session()

Get the session (Foswiki) object associated with the object when it was created.

ObjectMethod web([$name])

• $name - optional, change the web name in the object
  • Since 28 Nov 2008

Get/set the web name associated with the object.

ObjectMethod topic([$name])

• $name - optional, change the topic name in the object
  • Since 28 Nov 2008

Get/set the topic name associated with the object.

ObjectMethod getPath() → $objectpath

Get the canonical content access path for the object. For example, a topic "MyTopic" in subweb "Subweb" of web "Myweb" will have an access path "Myweb/Subweb.MyTopic"

ObjectMethod isSessionTopic() → $boolean

Return true if this object refers to the session topic. The session topic is established from the path used to invoke Foswiki, for example ".../view/Myweb/MyTopic" sets "Myweb.MyTopic" as the session topic.

ObjectMethod getPreference( $key ) → $value

Get a value for a preference defined in the object. Note that web preferences always inherit from parent webs, but topic preferences are strictly local to topics.

Note that this is not the same as Foswiki::Func::getPreferencesValue, which is almost certainly what you want to call instead.

ObjectMethod getContainer() → $containerObject

Get the container of this object; for example, the web that a topic is within

ObjectMethod existsInStore() → $boolean

A Meta object can be created for a web or topic that doesn't exist in the actual store (e.g. is in the process of being created). This method returns true if the corresponding web or topic really exists in the store.

ObjectMethod stringify( $debug ) → $string

Return a string version of the meta object. $debug adds extra debug info.

ObjectMethod addDependency() → $this

This establishes a caching dependency between $this and the base topic this session is currently rendering. The dependency will be asserted during Foswiki::PageCache::cachePage(). See Foswiki::PageCache::addDependency().

ObjectMethod fireDependency() → $this

Invalidates the cache bucket of the current meta object within the Foswiki::PageCache. See Foswiki::PageCache::fireDependency().

ObjectMethod isCacheable() → $boolean

Return true if page caching is enabled and this topic object is cacheable.

ObjectMethod populateNewWeb( [$baseWeb [, $opts]] )

$baseWeb is the name of an existing web (a template web). If the base web is a system web, all topics in it will be copied into this web. If it is a normal web, only topics starting with 'Web' will be copied. If no base web is specified, an empty web (with no topics) will be created. If it is specified but does not exist, an error will be thrown.

$opts is a ref to a hash that contains settings to be modified in the web preferences topic in the new web.

StaticMethod query($query, $inputTopicSet, \%options) → $outputTopicSet

Search for topic information $query must be a Foswiki::*::Node object.

• $inputTopicSet is a reference to an iterator containing a list of topic in this web, if set to undef, the search/query algo will create a new iterator using eachTopic() and the web, topic and excludetopics options (as per SEARCH)
• web option - The web/s to search in - string can have the same form as the web param of SEARCH

Returns an Foswiki::Search::InfoCache iterator

ObjectMethod eachWeb( $all ) → $iterator

Return an iterator over each subweb. If $all is set, will return a list of all web names under the current location. Returns web pathnames relative to $this.

Only valid on webs and the root.

ObjectMethod eachTopic() → $iterator

Return an iterator over each topic name in the web. Only valid on webs.

ObjectMethod eachAttachment() → $iterator

Return an iterator over each attachment name in the topic. Only valid on topics.

The list of the names of attachments stored for the given topic may be a longer list than the list that comes from the topic meta-data, which may only lists the attachments that are normally visible to the user.

ObjectMethod eachChange( $time ) → $iterator

Get an iterator over the list of all the changes to the object between $time and now. $time is a time in seconds since 1st Jan 1970, and is not guaranteed to return any changes that occurred before (now - {Store}{RememberChangesFor}). Changes are returned in most-recent-first order.

If the object is a web, changes for all topics within that web will be iterated. If it's a topic, then all changes to the topic will be iterated.

Each element of the iterator is a reference to a hash:

• verb - the action - one of
  • update - a web, topic or attachment has been modified
  • insert - a web, topic or attachment is being inserted
  • remove - a topic or attachment is being removed
• time - epoch-secs time of the change
• cuid - who is making the change
• revision - the revision of the topic that the change appears in
• path - canonical web.topic path for the affected object
• attachment - attachment name (optional)
• oldpath - canonical web.topic path for the origin of a move/rename
• oldattachment - origin of move
• minor - boolean true if this change is flagged as minor
• comment - descriptive text

Stores must return the following fields if compatibility with Foswiki < 2 is required.

• topic - name of the topic the change occurred to
• more - formatted string indicating if the change was minor or not
• user - wikiname of the changing user

The fields are deprecated and should not be used by core.

ObjectMethod loadVersion($rev) → $version

Load the object from the store. The object must not be already loaded with a different rev (verified by an ASSERT)

See getLoadedRev to determine what revision is currently being viewed.

• $rev - revision to load. If undef, 0, ” or > max available rev, will load the latest rev. If the revision is in range but does not exist, then will return an unloaded meta object (getLoadedRev() will be undef)

Returns the version identifier for the loaded revision. (and undef if it failed to load)

WARNING: see notes on revision numbers under getLoadedRev

ObjectMethod text([$text]) → $text

Get/set the topic body text. If $text is undef, gets the value, if it is defined, sets the value to that and returns the new text.

Be warned - it can return undef - when a topic exists but has no topicText.

ObjectMethod put($type, \%args)

Put a hash of key=value pairs into the given type set in this meta. This will not replace another value with the same name (for that see putKeyed)

For example,

$meta->put( 'FIELD', { name => 'MaxAge', title => 'Max Age', value =>'103' } );

ObjectMethod putKeyed($type, \%args)

Put a hash of key=value pairs into the given type set in this meta, replacing any existing value with the same key.

For example,

$meta->putKeyed( 'FIELD',
    { name => 'MaxAge', title => 'Max Age', value =>'103' } );

ObjectMethod putAll

Replaces all the items of a given key with a new array.

For example,

$meta->putAll( 'FIELD',
     { name => 'MinAge', title => 'Min Age', value =>'50' },
     { name => 'MaxAge', title => 'Max Age', value =>'103' },
     { name => 'HairColour', title => 'Hair Colour', value =>'white' }
 );

ObjectMethod get( $type, $key ) → \%hash

Find the value of a meta-datum in the map. If the type is keyed (identified by a name), the $key parameter is required to say which entry you want. Otherwise you will just get the first value.

If you want all the keys of a given type use the 'find' method.

The result is a reference to the hash for the item.

For example,

my $ma = $meta->get( 'FIELD', 'MinAge' );
my $topicinfo = $meta->get( 'TOPICINFO' ); # get the TOPICINFO hash

ObjectMethod find ( $type ) → @values

Get all meta data for a specific type. Returns the array stored for the type. This will be zero length if there are no entries.

For example,

my $attachments = $meta->find( 'FILEATTACHMENT' );

ObjectMethod remove($type, $key)

With no type, will remove all the meta-data in the object.

With a $type but no $key, will remove all items of that type (so for example if $type were FILEATTACHMENT it would remove all of them)

With a $type and a $key it will remove only the specific item.

ObjectMethod copyFrom( $otherMeta [, $type [, $nameFilter]] )

Copy all entries of a type from another meta data set. This will destroy the old values for that type, unless the copied object doesn't contain entries for that type, in which case it will retain the old values.

If $type is undef, will copy ALL TYPES.

If $nameFilter is defined (a perl regular expression), it will copy only data where {name} matches $nameFilter.

Does not copy web, topic or text.

ObjectMethod count($type) → $integer

Return the number of entries of the given type

ObjectMethod setRevisionInfo( %opts )

Set TOPICINFO information on the object, as specified by the parameters.

• version - the revision number
• time - the time stamp
• author - the user id (cUID)
• + additional data fields to save e.g. reprev, comment

ObjectMethod getRevisionInfo([$attachment [,$rev]]) → \%info

• $attachment - (optional) attachment name to get info about
• $rev - (optional) revision of attachment for which to get info

Return revision info for the loaded revision of a topic or attachment with at least:

• {date} in epochSec
• {author} canonical user ID
• {version} the revision number

ObjectMethod getRevisionInfo() → ( $revDate, $author, $rev, $comment )

Limited backwards compatibility for plugins that assume the 1.0.x interface The comment is always blank

ObjectMethod merge( $otherMeta, $formDef )

• $otherMeta - a block of meta-data to merge with $this
• $formDef reference to a Foswiki::Form that gives the types of the fields in $this

Merge the data in the other meta block.

• File attachments that only appear in one set are preserved.
• Form fields that only appear in one set are preserved.
• Form field values that are different in each set are text-merged
• We don't merge for field attributes or title
• Topic info is not touched
• The isTextMergeable method on the form def is used to determine if that field is mergeable. If it isn't, the value currently in meta will not be changed.

ObjectMethod forEachSelectedValue( $types, $keys, \&fn, \%options )

Iterate over the values selected by the regular expressions in $types and $keys.

• $types - regular expression matching the names of fields to be processed. Will default to qr/^[A-Z]+$/ if undef.
• $keys - regular expression matching the names of keys to be processed. Will default to qr/^[a-z]+$/ if undef.

Iterates over each value, calling \&fn on each, and replacing the value with the result of \&fn.

\%options will be passed on to $fn, with the following additions:

• _type => the type name (e.g. "FILEATTACHMENT")
• _key => the key name (e.g. "user")

ObjectMethod getParent() → $parent

Gets the TOPICPARENT name. Safe shortcut for =$meta→get('TOPICPARENT')→{name} Returns the emty string if there is no parent.

ObjectMethod getFormName() → $formname

Returns the name of the FORM, or ” if none.

ObjectMethod renderFormForDisplay() → $html

Render the form contained in the meta for display.

ObjectMethod renderFormFieldForDisplay($name, $format, $attrs) → $text

Render a single formfield, using the $format. See Foswiki::Form::FormField::renderForDisplay for a description of how the value is rendered.

ObjectMethod haveAccess($mode, $cUID) → $boolean

• $mode - 'VIEW', 'CHANGE', 'CREATE', etc. (defaults to VIEW)
• $cUID - Canonical user id (defaults to current user)

Check if the user has the given mode of access to the topic. This call may result in the topic being read.

ObjectMethod save( %options )

Save the current object, invoking appropriate plugin handlers

• %options - Hash of options, see saveAs for list of keys

ObjectMethod saveAs( $web, $topic, %options ) → $rev

Save the current topic to a store location. Only works on topics. without invoking plugins handlers.

• $web.$topic - where to move to (defaults to web.topic in the object)
• %options - Hash of options, may include:
  • forcenewrevision - force an increment in the revision number, even if content doesn't change.
  • dontlog - don't include this change in statistics
  • minor - don't notify this change
  • savecmd - Save command (core use only)
  • forcedate - force the revision date to be this (core only)
  • author - cUID of author of change (core only - default current user)
  • nohandlers - do not call plugins handlers

Note that the %options are passed on verbatim from Foswiki::Func::saveTopic, so an extension author can in fact use all these options. However those marked "core only" are for core use only and should not be used in extensions.

Returns the saved revision number.

ObjectMethod move($to, %opts)

Move this object (web or topic) to a store location specified by the object $to. %opts may include:

• user - cUID of the user doing the moving.

ObjectMethod deleteMostRecentRevision(%opts)

Delete (or elide) the most recent revision of this. Only works on topics.

%opts may include

• user - cUID of user doing the unlocking

ObjectMethod replaceMostRecentRevision( %opts )

Replace the most recent revision with whatever is in the memory copy. Only works on topics.

%opts may include:

• forcedate - try and re-use the date of the original check
• user - cUID of the user doing the action

ObjectMethod getRevisionHistory([$attachment]) → $iterator

Get an iterator over the range of version identifiers (just the identifiers, not the content) starting with the most recent revision.

The iterator will be empty ($iterator→hasNext() will be false) if the object does not exist.

$attachment is optional.

Not valid on webs.

ObjectMethod getLatestRev[$attachment]) → $revision

Get the revision ID of the latest revision.

$attachment is optional.

Not valid on webs.

Returns an integer revision number > 0 if the object exists.

Returns 0 if the object does not exist.

ObjectMethod latestIsLoaded() → $boolean

Return true if the currently loaded rev is the latest rev. Note that there may have been changes to the meta or text locally in the loaded meta; these changes will be retained.

Only valid on topics.

ObjectMethod getLoadedRev() → $integer

Get the currently loaded revision. Result will be a revision number, or undef if no revision has been loaded. Only valid on topics.

WARNING: some store implementations use the concept of a "working copy" of each topic that may be modified without being added to the revision control system. This means that the version number reported for the latest rev may not be the actual latest version.

ObjectMethod setLoadStatus($rev, $isLatest)

Used by the Store implementation to set the load status when a topic is read. Must be called by implementations of Foswiki::Store::readTopic. Do not use for anything else!

ObjectMethod removeFromStore( $attachment )

• $attachment - optional, provide to delete an attachment

Use with great care! Removes all trace of the given web, topic or attachment from the store, possibly including all its history.

Also does not ensure consistency of the store (for eg, if you delete an attachment, it does not update the in-topic META)

ObjectMethod getDifferences( $rev2, $contextLines ) → \@diffArray

Get the differences between the rev loaded into this object, and another rev of the same topic. Return reference to an array of differences.

• $rev2 - the other revision to diff against
• $contextLines - number of lines of context required

Each difference is of the form [ $type, $right, $left ] where

type	Means
+	Added
-	Deleted
c	Changed
u	Unchanged
l	Line Number

ObjectMethod getRevisionAtTime( $time ) → $rev

• $time - time (in epoch secs) for the rev

Get the revision number for a topic at a specific time. Returns a single-digit rev number or 0 if it couldn't be determined (either because the topic isn't that old, or there was a problem)

ObjectMethod setLease( $length )

Take out an lease on the given topic for this user for $length seconds.

See getLease for more details about Leases.

ObjectMethod getLease() → $lease

If there is an lease on the topic, return the lease, otherwise undef. A lease is a block of meta-information about a topic that can be recovered (this is a hash containing user, taken and expires). Leases are taken out when a topic is edited. Only one lease can be active on a topic at a time. Leases are used to warn if another user is already editing a topic.

ObjectMethod clearLease()

Cancel the current lease.

See getLease for more details about Leases.

ObjectMethod onTick($time)

Method invoked at regular intervals, usually by a cron job. The job of this method is to prod the store into cleaning up expired leases, and any other admin job that needs doing at regular intervals.

Deprecated ObjectMethod getAttachmentRevisionInfo($attachment, $rev) → \%info

• $attachment - attachment name
• $rev - optional integer attachment revision number

Get revision info for an attachment. Only valid on topics.

$info will contain at least: date, author, version, comment

Deprecated 2014-11-03 use getRevisionInfo instead.

ObjectMethod attach ( %opts )

• %opts may include:
  • name - Name of the attachment - required
  • dontlog - don't add to statistics
  • comment - comment for save
  • hide - if the attachment is to be hidden in normal topic view
  • stream - Stream of file to upload. Uses file if not set.
  • file - Name of a server file to use for the attachment data. This should be passed if it is known, as it may be used to optimise handler calls.
  • filepath - Optional. Client path to file.
  • filesize - Optional. Size of uploaded data.
  • filedate - Optional. Date of file.
  • author - Optional. cUID of author of change. Defaults to current.
  • notopicchange - Optional. if the topic is not to be modified. This may result in incorrect meta-data stored in the topic, so must be used with care. Only has a meaning if the store implementation stores meta-data in topics.
  • nohandlers - do not call plugin handlers

Saves a new revision of the attachment, invoking plugin handlers as appropriate. This method automatically updates the loaded rev of $this to the latest topic revision.

If neither of stream or file are set, this is a properties-only save.

Throws an exception on error.

ObjectMethod hasAttachment( $name ) → $boolean

Test if the named attachment exists. Only valid on topics. The attachment must exist in the store (it is not sufficient for it to be referenced in the object only)

ObjectMethod testAttachment( $name, $test ) → $value

Performs a type test on the given attachment file. * $name - name of the attachment to test e.g lolcat.gif * $test - the test to perform e.g. 'r'

The return value is the value that would be returned by the standard perl file operations, as indicated by $type

* r File is readable by current user (tests Foswiki VIEW permission) * w File is writable by current user (tests Foswiki CHANGE permission) * e File exists. * z File has zero size. * s File has nonzero size (returns size). * T File is an ASCII text file (heuristic guess). * B File is a "binary" file (opposite of T). * M Last modification time (epoch seconds). * A Last access time (epoch seconds).

Note that all these types should behave as the equivalent standard perl operator behaves, except M and A which are independent of the script start time (see perldoc -f -X for more information)

Other standard Perl file tests may also be supported on some store implementations, but cannot be relied on.

Errors will be signalled by an Error::Simple exception.

openAttachment($attachment, $mode, %opts) → $fh

• $attachment - the attachment
• $mode - mode to open the attachment in

Opens a stream onto the attachment. This method is primarily to support virtual file systems, and as such access controls are not checked, plugin handlers are not called, and it does not update the meta-data in the topicObject.

$mode can be '<', '>' or '>>' for read, write, and append respectively.

%opts can take different settings depending on $mode.

• $mode='<'
  • version - revision of the object to open e.g. version => 6
• $mode='>' or ='>>'
  • no options

Errors will be signalled by an Error exception.

See also attach if this function is too basic for you.

ObjectMethod moveAttachment( $name, $to, %opts ) → $data

Move the named attachment to the topic indicates by $to. %opts may include:

• new_name - new name for the attachment
• user - cUID of user doing the moving

ObjectMethod copyAttachment( $name, $to, %opts ) → $data

Copy the named attachment to the topic indicates by $to. %opts may include:

• new_name - new name for the attachment
• user - cUID of user doing the moving

ObjectMethod expandNewTopic()

Expand only that subset of Foswiki variables that are expanded during topic creation, in the body text and PREFERENCE meta only.

The expansion is in-place in the object data.

Only valid on topics.

ObjectMethod expandMacros( $text ) → $text

Expand only all Foswiki variables that are expanded during topic view. Returns the expanded text. Only valid on topics.

ObjectMethod renderTML( $text ) → $text

Render all TML constructs in the text into HTML. Returns the rendered text. Only valid on topics.

ObjectMethod summariseText( $flags [, $text, \%searchOptions] ) → $tml

Makes a plain text summary of the topic text by simply trimming a bit off the top. Truncates to $TMTRUNC chars or, if a number is specified in $flags, to that length.

If $text is defined, use it in place of the topic text.

The \%searchOptions hash may contain the following options:

• type - search type: keyword, literal, query
• casesensitive - false to ignore case (default true)
• wordboundaries - if type is 'keyword'
• tokens - array ref of search tokens

TODO: should this really be in Meta? it seems like a rendering issue to me.

warning: this will produce text that contains html entities - including quotes use $summary = Foswiki::entityEncode($summary); to diffuse them

ObjectMethod _summariseTextSimple( $text, $limit ) → $tml

Makes a plain text summary of the topic text by simply trimming a bit off the top. Truncates to $TMTRUNC chars or, if a number is specified in $flags, to that length.

TODO: should this really be in Meta? it seems like a rendering issue to me.

ObjectMethod _summariseTextWithSearchContext( $text, $limit, $type, $searchOptions ) → $tml

Improves the presentation of summaries for keyword, word and literal searches, by displaying topic content on either side of the search terms wherever they are found in the topic.

The \%searchOptions hash may contain the following options:

• type - search type: keyword, literal, query
• casesensitive - false to ignore case (default true)
• wordboundaries - if type is 'keyword'
• tokens - array ref of search tokens

ObjectMethod summariseChanges( $orev, $nrev, $tml, $nochecks) → $text

Generate a (max 3 line) summary of the differences between the revs.

• $orev - older rev, if not defined will use ($nrev - 1)
• $nrev - later rev, if not defined defaults to latest
• $tml - if true will generate renderable TML (i.e. HTML with NOPs. If false will generate a summary suitable for use in plain text (mail, for example)
• $nochecks - if true, access control checks will be suppressed

If there is only one rev, a topic summary will be returned.

If $tml is not set, all HTML will be removed.

In non-tml, lines are truncated to 70 characters. Differences are shown using + and - to indicate added and removed text.

Deprecated ObjectMethod getEmbeddedStoreForm() → $text

Generate the embedded store form of the topic. The embedded store form has meta-data values embedded using %META: lines. The text stored in the meta is taken as the topic text.

Deprecated 2014-11-13, and will be removed in Foswiki 2.0. It is retained for compatibility only. use Foswiki::Serialise::serialise($meta, 'Embedded') instead.

Deprecated ObjectMethod setEmbeddedStoreForm( $text )

Populate this object with embedded meta-data from $text. This method is a utility provided for use with stores that store data embedded in topic text. Only valid on topics.

Note: line endings must be normalised to \n before calling this method.

Deprecated 2014-11-13, and will be removed in Foswiki 2.0. It is retained for compatibility only. use Foswiki::Serialise::deserialise($text, 'Embedded', $meta) instead.

StaticMethod isValidEmbedding($macro, \%args) → $boolean

Test that the arguments defined in \%args are sufficient to satisfy the requirements of the embeddable meta-data given by $macro. For example, isValidEmbedding('FILEATTACHMENT', $args) will only succeed if $args contains at least name, date, user and attr fields. Note that extra fields are simply ignored (unless they are explicitly excluded).

If the macro is not registered for validation, then it will be ignored.

If the embedding is not valid, then $Foswiki::Meta::reason is set with a message explaining why.

StaticMethod dataDecode( $encoded ) → $decoded

Decode escapes in a string that was encoded using dataEncode

The encoding has to be exported because Foswiki (and plugins) use encoded field data in other places e.g. RDiff, mainly as a shorthand for the properly parsed meta object. Some day we may be able to eliminate that….

ClassMethod type() → $resourcetype

(see Foswiki::Address::type)

Returns the resource type name.

• webpath, Eg. Web/SubWeb/
• topic, Eg. =Web/SubWeb.
• undef, I have no idea whats going on, we're not there yet