Difference between revisions of "API:EPrints/DataObj"

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To create a new object in the database use:
 
To create a new object in the database use:
$obj = $ds->create_object( $handle, $data ); =cut
 
  
###################################################################### #
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  $obj = $ds->create_object( $handle, $data );
# INSTANCE VARIABLES: #
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$self->{data} #    A reference to a hash containing the metadata of this #    record. #
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$self->{handle} #    The current EPrints::Handle #
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#  $self->{dataset} #    The EPrints::DataSet to which this record belongs. #
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######################################################################
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package EPrints::DataObj;
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use MIME::Base64 ();
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use strict;
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###################################################################### # $sys_fields = EPrints::DataObj->get_system_field_info #  # Return an array describing the system metadata of the this  # dataset. ######################################################################
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sub get_system_field_info {
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my( $class ) = @_;
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  return (); }
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###################################################################### =pod
 
 
 
<div style='background-color: #e8e8f; margin: 0.5em 0em 1em 0em; border: solid 1px #cce;  padding: 0em 1em 0em 1em; font-size: 80%; '>
 
<div style='background-color: #e8e8f; margin: 0.5em 0em 1em 0em; border: solid 1px #cce;  padding: 0em 1em 0em 1em; font-size: 80%; '>
 
<h4><span style='display:none'>User Comments</span></h4>
 
<h4><span style='display:none'>User Comments</span></h4>

Revision as of 19:18, 25 August 2009


EPrints 3 Reference: Directory Structure - Metadata Fields - Repository Configuration - XML Config Files - XML Export Format - EPrints data structure - Core API - Data Objects


API: Core API

Latest Source Code (3.3, 3.2) | Revision Log | Before editing this page please read Pod2Wiki


NAME

EPrints::DataObj - Base class for records in EPrints.

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SYNOPSIS

 $dataobj = EPrints::DataObj->new( $handle, $id [, $dataset] );
 $dataobj = $dataset->get_object( $id );
 $dataobj = $handle->get_XXXXX( $id );
 
 $handle = $dataobj->get_handle;
 $dataset = $dataobj->get_dataset;
 
 $id = $dataobj->get_id;
 $uri = $dataobj->uri;
 $url = $dataobj->get_url;
 $url = $dataobj->get_control_url;
 
 $value = $dataobj->get_value( $fieldname );
 $bool = $dataobj->is_set( $fieldname );
 $bool = $dataobj->exists_and_set( $fieldname );
 
 $success = $dataobj->remove;
 
 $dataobj->set_value( $fieldname, $value );
 $success = $dataobj->commit( [$force] );
 
 $xhtml = $dataobj->render_value( $fieldname, [$showall] );
 $xhtml = $dataobj->render_citation( [$style], [%params] );
 $xhtml = $dataobj->render_citation_link( [$style], %params );
 $xhtml = $dataobj->render_citation_link_staff( [$style], %params );
 $xhtml = $dataobj->render_description;
 ($xhtml, $title ) = $dataobj->render;
 ($xhtml, $title ) = $dataobj->render_full;
 
 $plugin_output = $dataobj->export( $plugin_id [,%params] );
 

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DESCRIPTION

This module is a base class which is inherited by EPrints::DataObj::EPrint, EPrints::User, EPrints::DataObj::Subject and EPrints::DataObj::Document and several other classes.

It is ABSTRACT - these methods should not be called directly.

To create a new object in the database use:

 $obj = $ds->create_object( $handle, $data );
 

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$dataobj = EPrints::DataObj->new( $handle, $id [, $dataset] )

Return new data object, created by loading it from the database.

If $dataset is not defined uses the default dataset for this object.

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$handle = $dataobj->get_handle

Returns the EPrints::Handle object to which this record belongs.

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$success = $dataobj->remove

Remove this data object from the database and any sub-objects or related files.

Return true if successful.

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$success = $dataobj->commit( [$force] )

Write this object to the database and reset the changed fields.

If $force isn't true then it only actually modifies the database if one or more fields have been changed.

Commit may also queue indexer jobs or log changes, depending on the object.

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$value = $dataobj->get_value( $fieldname )

Get a the value of a metadata field. If the field is not set then it returns undef unless the field has the property multiple set, in which case it returns [] (a reference to an empty array).

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$dataobj->set_value( $fieldname, $value )

Set the value of the named metadata field in this record.

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@values = $dataobj->get_values( $fieldnames )

Returns a list of all the values in this record of all the fields specified by $fieldnames. $fieldnames should be in the format used by browse views - slash seperated fieldnames with an optional .id suffix to indicate the id part rather than the main part.

For example "author.id/editor.id" would return a list of all author and editor ids from this record.

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$data = $dataobj->get_data

Returns a reference to the hash table of all the metadata for this record keyed by fieldname.

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$bool = $dataobj->is_set( $fieldname )

Returns true if the named field is set in this record, otherwise false.

Warns if the field does not exist.

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$bool = $dataobj->exists_and_set( $fieldname )

Returns true if the named field is set in this record, otherwise false.

If the field does not exist, just return false.

This method is useful for plugins which may operate on multiple repositories, and the fact a field does not exist is not an issue.

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$xhtml = $dataobj->render_value( $fieldname, [$showall] )

Returns the rendered version of the value of the given field, as appropriate for the current session. If $showall is true then all values are rendered - this is usually used for staff viewing data.

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$xhtml = $dataobj->render_citation( [$style], [%params] )

Renders the record as a citation. If $style is set then it uses that citation style from the citations config file. Otherwise $style defaults to the type of this record. If $params{url} is set then the citiation will link to the specified URL.

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$xhtml = $dataobj->render_citation_link( [$style], %params )

Renders a citation (as above) but as a link to the URL for this item. For example - the abstract page of an eprint.

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$xhtml = $dataobj->render_citation_link_staff( [$style], %params )

As for render_citation_link but the link goes to the edit URL for the item.

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$xhtml = $dataobj->render_description

Returns a short description of this object using the "brief" citation style for this dataset.

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($xhtml, $title ) = $dataobj->render

Return a chunk of XHTML DOM describing this object in the normal way. This is the public view of the record, not the staff view.

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($xhtml, $title ) = $dataobj->render_full

Return an XHTML table in DOM describing this record. All values of all fields are listed. This is the staff view.

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$id = $dataobj->get_id

Returns the value of the primary key of this record.

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$dataset = $dataobj->get_dataset

Returns the EPrints::DataSet object to which this record belongs.

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$uri = $dataobj->uri

Returns a unique URI for this object. Not certain to resolve as a URL.

The URI is generally of the form repository_url/id/datasetid/dataobj_id

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$url = $dataobj->get_url

Returns the URL for this record, for example the URL of the abstract page of an eprint.

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$url = $dataobj->get_control_url

Returns the URL for the control page for this object.

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$plugin_output = $dataobj->export( $plugin_id [,%params] )

Apply an output plugin to this items. Return the results. No additional parameters are required for most export plugins.

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$boolean = $dataobj->has_owner( $user )

Return true if $user owns this record. Normally this means they created it, but a group of users could count as owners of the same record if you wanted.

It's false on most dataobjs, except those which override this method.

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$boolean = $dataobj->in_editorial_scope_of( $user )

As for has_owner, but if the user is identified as someone with an editorial scope which includes this record.

Defaults to true. Which doesn't mean that they have the right to edit it, just that their scope matches. You also need editor rights to use this. It's currently used just to filter eprint editors so that only ones with a scope AND a priv can edit.

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$problems = $dataobj->validate( [ $for_archive ], $workflow_id )

Return a reference to an array of XHTML DOM objects describing validation problems with the entire $dataobj based on $workflow_id.

If $workflow_id is undefined defaults to "default".

A reference to an empty array indicates no problems.

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$warnings = $dataobj->get_warnings( )

Return a reference to an array of XHTML DOM objects describing problems with the entire $dataobj.

A reference to an empty array indicates no problems.

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$file = $dataobj->add_stored_file( $filename, $filehandle [, $filesize ] )

Convenience method to add the file record for $filename to this object. Reads data from $filehandle. If $filesize is defined it may used to determine where the file should be stored.

Returns the file object or undef if the storage failed.

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$file = $dataobj->get_stored_file( $filename )

Get the file object for $filename.

Returns the file object or undef if the file doesn't exist.

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Related Objects

These methods have been introduced in ep3.2 to describe the relationships between objects in the system.

See the wiki for more detailed discussion of how to use these.

 $dataobj->add_object_relations( $target, $has => $is [, $has => $is ] )
 $bool = $dataobj->has_object_relations( $target, @types )
 $bool = $dataobj->has_related_objects( @types )
 $dataobjs = $dataobj->get_related_objects( @types )
 $dataobj->remove_object_relations( $target [, $has => $is [, $has => $is ] )
 

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$dataobj->add_object_relations( $target, $has => $is [, $has => $is ] )

Add a relation between this object and $target of type $has. If $is is defined will also add the reciprocal relationship $is from $target to this object. May be repeated to add multiple relationships.

You must commit $target after calling this method.

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$bool = $dataobj->has_object_relations( $target, @types )

Returns true if this object is related to $target by all @types.

If @types is empty will return true if any relationships exist.

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$bool = $dataobj->has_related_objects( @types )

Returns true if get_related_objects() would return some objects, but without actually retrieving the related objects from the database.

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$dataobjs = $dataobj->get_related_objects( @types )

Returns a list of objects related to this object by @types.

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$dataobj->remove_object_relations( $target [, $has => $is [, $has => $is ] )

Remove relations between this object and $target. If $has => $is pairs are defined will only remove those relationships given.

You must commit $target after calling this method.

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