Class: ActiveFedora::MetadataDatastream
- Inherits:
-
Datastream
- Object
- Fedora::BaseObject
- Fedora::Datastream
- Datastream
- ActiveFedora::MetadataDatastream
- Includes:
- MetadataDatastreamHelper
- Defined in:
- lib/active_fedora/metadata_datastream.rb
Overview
A legacy class that creates and updates simple xml documents For much greater flexibility, use NokogiriDatastream instead.
Direct Known Subclasses
Instance Attribute Summary
Attributes included from MetadataDatastreamHelper
Attributes inherited from Datastream
#dirty, #fields, #last_modified
Attributes inherited from Fedora::BaseObject
#attributes, #blob, #errors, #new_object, #uri
Class Method Summary collapse
-
.from_xml(tmpl, node) ⇒ Object
Populate a MetadataDatastream object based on the “datastream” node from a FOXML file.
Instance Method Summary collapse
-
#field(name, tupe, opts = {}) ⇒ Object
This method generates the various accessor and mutator methods on self for the datastream metadata attributes.
- #get_values(field_name, default = []) ⇒ Object
- #set_value(field_name, values) ⇒ Object
- #update_attributes(params = {}, opts = {}) ⇒ Object
-
#update_indexed_attributes(params = {}, opts = {}) ⇒ Object
An ActiveRecord-ism to udpate metadata values.
Methods included from MetadataDatastreamHelper
#from_solr, included, #initialize, #save, #set_blob_for_save, #to_solr, #to_xml
Methods inherited from Datastream
#after_save, #before_save, #check_concurrency, #content, #content=, delete, #delete, #dirty?, #dsid=, #initialize, #last_modified_in_repository, #pid, #pid=, #save, #size, #to_param
Methods inherited from Fedora::Datastream
#control_group, #control_group=, #dsid, #initialize, #label, #label=, #mime_type, #mime_type=, #pid, #uri, #url
Methods inherited from Fedora::BaseObject
#[], #initialize, #new_object?
Class Method Details
.from_xml(tmpl, node) ⇒ Object
Populate a MetadataDatastream object based on the “datastream” node from a FOXML file
136 137 138 139 140 141 142 |
# File 'lib/active_fedora/metadata_datastream.rb', line 136 def self.from_xml(tmpl, node) # :nodoc: node.xpath("./foxml:datastreamVersion[last()]/foxml:xmlContent/fields/node()").each do |f| tmpl.send("#{f.name}_append", f.text) unless f.class == Nokogiri::XML::Text end tmpl.send(:dirty=, false) tmpl end |
Instance Method Details
#field(name, tupe, opts = {}) ⇒ Object
This method generates the various accessor and mutator methods on self for the datastream metadata attributes. each field will have the 3 magic methods:
name_values=(arg)
name_values
name_append(arg)
Calling any of the generated methods marks self as dirty.
‘tupe’ is a datatype, currently :string, :text and :date are supported.
opts is an options hash, which will affect the generation of the xml representation of this datastream.
Currently supported modifiers: For QualifiedDublinCorDatastreams
:
:element_attrs =>{:foo=>:bar} - hash of xml element attributes
:xml_node => :nodename - The xml node to be used to represent this object (in dcterms namespace)
:encoding=>foo, or encodings_scheme - causes an xsi:type attribute to be set to 'foo'
:multiple=>true - mark this field as a multivalue field (on by default)
At some point, these modifiers will be ported up to work for any ActiveFedora::MetadataDatastream
.
There is quite a good example of this class in use in spec/examples/oral_history.rb
!! Careful: If you declare two fields that correspond to the same xml node without any qualifiers to differentiate them, you will end up replicating the values in the underlying datastream, resulting in mysterious dubling, quadrupling, etc. whenever you edit the field’s values.
171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 |
# File 'lib/active_fedora/metadata_datastream.rb', line 171 def field(name, tupe, opts={}) @fields[name.to_s.to_sym]={:type=>tupe, :values=>[]}.merge(opts) eval <<-EOS def #{name}_values=(arg) @fields["#{name.to_s}".to_sym][:values]=[arg].flatten self.dirty=true end def #{name}_values @fields["#{name}".to_sym][:values] end def #{name}_append(arg) @fields["#{name}".to_sym][:values] << arg self.dirty =true end EOS end |
#get_values(field_name, default = []) ⇒ Object
107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 |
# File 'lib/active_fedora/metadata_datastream.rb', line 107 def get_values(field_name, default=[]) field_accessor_method = "#{field_name}_values" if respond_to? field_accessor_method values = self.send(field_accessor_method) else values = [] end if values.empty? if default.nil? return default else return default end else return values end end |
#set_value(field_name, values) ⇒ Object
125 126 127 128 129 130 131 |
# File 'lib/active_fedora/metadata_datastream.rb', line 125 def set_value(field_name, values) field_accessor_method = "#{field_name}_values=" if respond_to? field_accessor_method values = self.send(field_accessor_method, values) return self.send("#{field_name}_values") end end |
#update_attributes(params = {}, opts = {}) ⇒ Object
16 17 18 19 20 21 22 23 24 25 26 27 28 29 |
# File 'lib/active_fedora/metadata_datastream.rb', line 16 def update_attributes(params={},opts={}) result = params.dup params.each do |k,v| if v == :delete || v == "" || v == nil v = [] end if self.fields.has_key?(k.to_sym) result[k] = set_value(k, v) else result.delete(k) end end return result end |
#update_indexed_attributes(params = {}, opts = {}) ⇒ Object
An ActiveRecord-ism to udpate metadata values.
The passed in hash must look like this :
{:name=>{"0"=>"a","1"=>"b"}}
This will attempt to set the values for any field named fubar in the datastream. If there is no field by that name, it returns an empty hash and doesn’t change the object at all. If there is a field by that name, it will set the values for field of name :name having the value [a,b] and it returns a hash with the field name, value index, and the value as it was set.
An index of -1 will insert a new value. any existing value at the relevant index will be overwritten.
As in update_attributes, this overwrites all available fields by default.
Example Usage:
ds.update_attributes(:myfield=>{“0”=>“a”,“1”=>“b”,:myotherfield=>“-1”=>“c”})
50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 |
# File 'lib/active_fedora/metadata_datastream.rb', line 50 def update_indexed_attributes(params={}, opts={}) ##FIX this bug, it should delete it from a copy of params in case passed to another datastream for update since this will modify params ##for subsequent calls if updating more than one datastream in a single update_indexed_attributes call current_params = params.clone # remove any fields from params that this datastream doesn't recognize current_params.delete_if do |field_name,new_values| if field_name.kind_of?(Array) then field_name = field_name.first end !self.fields.include?(field_name.to_sym) end result = current_params.dup current_params.each do |field_name,new_values| if field_name.kind_of?(Array) then field_name = field_name.first end ##FIX this bug, it should delete it from a copy of params in case passed to another datastream for update #if field does not exist just skip it next if !self.fields.include?(field_name.to_sym) field_accessor_method = "#{field_name}_values" if new_values.kind_of?(Hash) result[field_name] = new_values.dup current_values = instance_eval(field_accessor_method) # current_values = get_values(field_name) # for some reason this leaves current_values unset? new_values.delete_if do |y,z| if current_values[y.to_i] and y.to_i > -1 current_values[y.to_i]=z true else false end end new_values.each do |y,z| result[field_name].delete(y) current_values<<z #just append everything left new_array_index = current_values.length - 1 result[field_name][new_array_index.to_s] = z end current_values.delete_if {|x| x == :delete || x == "" || x == nil} #set_value(field_name, current_values) instance_eval("#{field_accessor_method}=(current_values)") #write it back to the ds # result[field_name].delete("-1") else values = instance_eval("#{field_name}_values=(new_values)") result[field_name] = {"0"=>values} end self.dirty = true end return result end |