Class: ActiveFedora::OmDatastream
- Inherits:
-
Datastream
- Object
- Rubydora::Datastream
- Datastream
- ActiveFedora::OmDatastream
- Includes:
- Datastreams::NokogiriDatastreams, OM::XML::Document, OM::XML::TerminologyBasedSolrizer
- Defined in:
- lib/active_fedora/om_datastream.rb
Direct Known Subclasses
Instance Attribute Summary collapse
-
#internal_solr_doc ⇒ Object
Returns the value of attribute internal_solr_doc.
Attributes inherited from Datastream
#digital_object, #last_modified
Class Method Summary collapse
Instance Method Summary collapse
- #find_by_terms(*termpointer) ⇒ Object
-
#from_solr(solr_doc) ⇒ Object
** Experimental **.
- #generate_solr_symbol(base, data_type) ⇒ Object
- #get_values(field_key, default = []) ⇒ Object
-
#get_values_from_solr(*term_pointer) ⇒ Array
** Experimental ** This method is called by
get_values
if this datastream has been initialized by calling from_solr method via ActiveFedora::Base.load_instance_from_solr. -
#has_solr_name?(name, solr_doc = Hash.new) ⇒ Boolean
** Experimental **.
-
#is_hierarchical_term_pointer?(*term_pointer) ⇒ Boolean
** Experimental ** ====Example: [:image, :title_set=>1, :title] return true [:image, :title_set, :title] return false.
-
#metadata? ⇒ Boolean
Indicates that this datastream has metadata content.
- #om_term_values ⇒ Object
- #om_update_values ⇒ Object
-
#term_values(*term_pointer) ⇒ Object
override OM::XML::term_values so can lazy load from solr if this datastream initialized using
from_solr
. -
#to_solr(solr_doc = {}) ⇒ Object
Return a hash suitable for indexing in solr.
-
#update_indexed_attributes(params = {}, opts = {}) ⇒ Object
Update field values within the current datastream using #update_values, which is a wrapper for OM::TermValueOperators#update_values Ignores any fields from params that this datastream’s Terminology doesn’t recognize .
-
#update_values(params = {}) ⇒ Object
Update values in the datastream’s xml This wraps OM::TermValueOperators#update_values so that returns an error if we have loaded from solr since datastreams loaded that way should be read-only.
Methods included from Datastreams::NokogiriDatastreams
#autocreate?, #content=, #content_changed?, #datastream_content, #local_or_remote_content, #ng_xml, #ng_xml=, #ng_xml_changed?, #ng_xml_doesnt_change!, #ng_xml_will_change!, #to_xml, #xml_loaded
Methods inherited from Datastream
#create, #freeze, #frozen?, #initialize, #inspect, #label, #profile_from_hash, #realLabel, #save, #serialize!, #solrize_profile, #to_param
Constructor Details
This class inherits a constructor from ActiveFedora::Datastream
Instance Attribute Details
#internal_solr_doc ⇒ Object
Returns the value of attribute internal_solr_doc.
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# File 'lib/active_fedora/om_datastream.rb', line 20 def internal_solr_doc @internal_solr_doc end |
Class Method Details
.default_attributes ⇒ Object
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# File 'lib/active_fedora/om_datastream.rb', line 22 def self.default_attributes super.merge(:controlGroup => 'M', :mimeType => 'text/xml') end |
Instance Method Details
#find_by_terms(*termpointer) ⇒ Object
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# File 'lib/active_fedora/om_datastream.rb', line 270 def find_by_terms(*termpointer) super end |
#from_solr(solr_doc) ⇒ Object
** Experimental **
This method is called by ActiveFedora::Base.load_instance_from_solr in order to initialize a nokogiri datastreams values from a solr document. This method merely sets the internal_solr_doc to the document passed in. Then any calls to get_values get values from the solr document on demand instead of directly from the xml stored in Fedora. This should be used for read-only purposes only, and instances where you want to improve performance by getting data from solr instead of Fedora.
See ActiveFedora::Base.load_instance_from_solr and get_values_from_solr
for more information.
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# File 'lib/active_fedora/om_datastream.rb', line 43 def from_solr(solr_doc) #just initialize internal_solr_doc since any value retrieval will be done via lazy loading on this doc on-demand @internal_solr_doc = solr_doc end |
#generate_solr_symbol(base, data_type) ⇒ Object
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# File 'lib/active_fedora/om_datastream.rb', line 188 def generate_solr_symbol(base, data_type) ActiveFedora::SolrService.solr_name([prefix,base].join, type: data_type) end |
#get_values(field_key, default = []) ⇒ Object
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# File 'lib/active_fedora/om_datastream.rb', line 265 def get_values(field_key,default=[]) term_values(*field_key) end |
#get_values_from_solr(*term_pointer) ⇒ Array
** Experimental ** This method is called by get_values
if this datastream has been initialized by calling from_solr method via ActiveFedora::Base.load_instance_from_solr. This method retrieves values from a preinitialized @internal_solr_doc instead of xml. This makes the datastream read-only and this method is not intended to be used in any other case.
Values are retrieved from the @internal_solr_doc on-demand instead of via xml preloaded into memory.
A term_pointer is passed in and if it contains hierarchical indexes it will detect which solr field values need to be returned.
Example 1 (non-hierarchical term_pointer):
term_pointer = [:image, :title_set, :title]
Returns value of "image_title_set_title_t" in @internal_solr_doc
Example 2 (hierarchical term_pointer that contains one or more indexes):
term_pointer = [:image, {:title_set=>1}, :title]
relevant xml:
<image>
<title_set>
<title>Title 1</title>
</title_set>
</image>
<image>
<title_set>
<title>Title 2</title>
</title_set>
<title_set>
<title>Title 3</title>
</title_set>
</image>
Repeating element nodes are indexed and will be stored in solr as follows:
image_0_title_set_0_title_t = "Title 1"
image_1_title_set_0_title_t = "Title 2"
image_1_title_set_1_title_t = "Title 3"
Even though no image element index is specified, only the second image element has two title_set elements so the expected return value is
["Title 3"]
While loading from solr the xml hierarchy is not immediately apparent so we must detect first how many image elements with a title_set element exist
and then check which of those elements have a second title element.
As this nokogiri datastream is indexed in solr, a value at each level in the tree will be stored independently and therefore
if 'image_0_title_set_0_title_t' exists in solr 'image_0_title_set_t' will also exist in solr.
So, we will build up the relevant solr names incrementally for a given term_pointer. The last element in the
solr_name will not contain an index.
It then will do the following:
Because no index is supplied for :image it will detect which indexes exist in solr
image_0_title_set_t (found key and add 'image_0_title_set' to base solr_name list)
image_1_title_set_t (found key and add 'image_0_title_set' to base solr_name list)
image_2_title_set_t (not found and stop checking indexes for image)
After iteration 1:
bases = ["image_0_title_set","image_1_title_set"]
Two image nodes were found and next sees index of 1 supplied for title_set so just uses index of 1 building off bases found in previous iteration
image_0_title_set_1_title_t (not found remove 'image_0_title_set' from base solr_name list)
image_1_title_set_1_title_t (found and replace 'image_1_title_set' with new base 'image_1_title_set_1_title')
After iteration 2:
bases = ["image_1_title_set_1_title"]
It always looks ahead one element so we check if any elements are after title. There are not any other elements so we are done iterating.
returns @internal_solr_doc["image_1_title_set_1_title_t"]
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# File 'lib/active_fedora/om_datastream.rb', line 122 def get_values_from_solr(*term_pointer) values = [] solr_doc = @internal_solr_doc return values if solr_doc.nil? term = self.class.terminology.retrieve_term(*OM.pointers_to_flat_array(term_pointer, false)) #check if hierarchical term pointer if is_hierarchical_term_pointer?(*term_pointer) # if we are hierarchical need to detect all possible node values that exist # we do this by building up the possible solr names parent by parent and/or child by child # if an index is supplied for any node in the pointer it will be used # otherwise it will include all nodes and indexes that exist in solr bases = [] #add first item in term_pointer as start of bases # then iterate through possible nodes that might exist term_pointer.first.kind_of?(Hash) ? bases << term_pointer.first.keys.first : bases << term_pointer.first for i in 1..(term_pointer.length-1) #iterate in reverse so that we can modify the bases array while iterating (bases.length-1).downto(0) do |j| current_last = (term_pointer[i].kind_of?(Hash) ? term_pointer[i].keys.first : term_pointer[i]) if (term_pointer[i-1].kind_of?(Hash)) #just use index supplied instead of trying possibilities index = term_pointer[i-1].values.first solr_name_base = OM::XML::Terminology.term_hierarchical_name({bases[j]=>index},current_last) solr_name = generate_solr_symbol(solr_name_base, term.type) bases.delete_at(j) #insert the new solr name base if found bases.insert(j,solr_name_base) if has_solr_name?(solr_name,solr_doc) else #detect how many nodes exist index = 0 current_base = bases[j] bases.delete_at(j) solr_name_base = OM::XML::Terminology.term_hierarchical_name({current_base=>index},current_last) solr_name = generate_solr_symbol(solr_name_base, term.type) #check for indexes that exist until we find all nodes while has_solr_name?(solr_name,solr_doc) do #only reinsert if it exists bases.insert(j,solr_name_base) index = index + 1 solr_name_base = OM::XML::Terminology.term_hierarchical_name({current_base=>index},current_last) solr_name = generate_solr_symbol(solr_name_base, term.type) end end end end #all existing applicable solr_names have been found and we can now grab all values and build up our value array bases.each do |base| field_name = generate_solr_symbol(base.to_sym, term.type) value = (solr_doc[field_name].nil? ? solr_doc[field_name.to_s]: solr_doc[field_name]) unless value.nil? value.is_a?(Array) ? values.concat(value) : values << value end end else #this is not hierarchical and we can simply look for the solr name created using the terms without any indexes generic_field_name_base = OM::XML::Terminology.term_generic_name(*term_pointer) generic_field_name = generate_solr_symbol(generic_field_name_base, term.type) value = (solr_doc[generic_field_name].nil? ? solr_doc[generic_field_name.to_s]: solr_doc[generic_field_name]) unless value.nil? value.is_a?(Array) ? values.concat(value) : values << value end end values end |
#has_solr_name?(name, solr_doc = Hash.new) ⇒ Boolean
** Experimental **
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# File 'lib/active_fedora/om_datastream.rb', line 196 def has_solr_name?(name, solr_doc=Hash.new) !solr_doc[name].nil? || !solr_doc[name.to_s].nil? end |
#is_hierarchical_term_pointer?(*term_pointer) ⇒ Boolean
** Experimental **
Example:
[:image, {:title_set=>1}, :title] return true
[:image, :title_set, :title] return false
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# File 'lib/active_fedora/om_datastream.rb', line 205 def is_hierarchical_term_pointer?(*term_pointer) if term_pointer.length>1 term_pointer.each do |pointer| if pointer.kind_of?(Hash) return true end end end return false end |
#metadata? ⇒ Boolean
Indicates that this datastream has metadata content.
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# File 'lib/active_fedora/om_datastream.rb', line 28 def true end |
#om_term_values ⇒ Object
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# File 'lib/active_fedora/om_datastream.rb', line 17 alias_method(:om_term_values, :term_values) |
#om_update_values ⇒ Object
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# File 'lib/active_fedora/om_datastream.rb', line 18 alias_method(:om_update_values, :update_values) |
#term_values(*term_pointer) ⇒ Object
override OM::XML::term_values so can lazy load from solr if this datastream initialized using from_solr
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# File 'lib/active_fedora/om_datastream.rb', line 292 def term_values(*term_pointer) # TODO if we can add primary_solr_name onto OmDatastream, we may be able to do away with get_values_from_solr. if @internal_solr_doc #lazy load values from solr on demand get_values_from_solr(*term_pointer) else om_term_values(*term_pointer) end end |
#to_solr(solr_doc = {}) ⇒ Object
Return a hash suitable for indexing in solr. Every field name is prefixed with the value returned by the prefix
method.
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# File 'lib/active_fedora/om_datastream.rb', line 50 def to_solr(solr_doc = {}) prefix = self.prefix solr_doc.merge super({}).each_with_object({}) { |(key, value), new| new[[prefix,key].join] = value } end |
#update_indexed_attributes(params = {}, opts = {}) ⇒ Object
Update field values within the current datastream using #update_values, which is a wrapper for OM::TermValueOperators#update_values Ignores any fields from params that this datastream’s Terminology doesn’t recognize
Example:
@mods_ds.update_indexed_attributes( {[{":person"=>"0"}, "role"]=>{"0"=>"role1", "1"=>"role2", "2"=>"role3"} })
=> {"person_0_role"=>{"0"=>"role1", "1"=>"role2", "2"=>"role3"}}
@mods_ds.to_xml # (the following is an approximation)
<mods>
<mods:name type="person">
<mods:role>
<mods:roleTerm>role1</mods:roleTerm>
</mods:role>
<mods:role>
<mods:roleTerm>role2</mods:roleTerm>
</mods:role>
<mods:role>
<mods:roleTerm>role3</mods:roleTerm>
</mods:role>
</mods:name>
</mods>
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# File 'lib/active_fedora/om_datastream.rb', line 241 def update_indexed_attributes(params={}, opts={}) if self.class.terminology.nil? raise "No terminology is set for this OmDatastream class. Cannot perform update_indexed_attributes" end # remove any fields from params that this datastream doesn't recognize # make sure to make a copy of params so not to modify hash that might be passed to other methods current_params = params.clone current_params.delete_if do |term_pointer,new_values| if term_pointer.kind_of?(String) ActiveFedora::Base.logger.warn "WARNING: #{dsid} ignoring {#{term_pointer.inspect} => #{new_values.inspect}} because #{term_pointer.inspect} is a String (only valid OM Term Pointers will be used). Make sure your html has the correct field_selector tags in it." if ActiveFedora::Base.logger true else !self.class.terminology.has_term?(*OM.destringify(term_pointer)) end end result = {} unless current_params.empty? result = update_values( current_params ) end return result end |
#update_values(params = {}) ⇒ Object
Update values in the datastream’s xml This wraps OM::TermValueOperators#update_values so that returns an error if we have loaded from solr since datastreams loaded that way should be read-only
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# File 'lib/active_fedora/om_datastream.rb', line 280 def update_values(params={}) raise "can't modify frozen #{self.class}" if frozen? if @internal_solr_doc raise "No update performed, this object was initialized via Solr instead of Fedora and is therefore read-only. Please utilize ActiveFedora::Base.find to first load object via Fedora instead." else ng_xml_will_change! result = om_update_values(params) return result end end |