Class | Ferret::Search::SortField |
In: |
ext/r_search.c
|
Parent: | Object |
A SortField is used to sort the result-set of a search be the contents of a field. The following types of sort_field are available;
The type of the SortField is set by passing it as a parameter to the constructor. The +:auto+ type specifies that the SortField should detect the sort type by looking at the data in the field. This is the default :type value although it is recommended that you explicitly specify the fields type.
title_sf = SortField.new(:title, :type => :string) rating_sf = SortField.new(:rating, :type => float, :reverse => true)
Note 1: Care should be taken when using the :auto sort-type since numbers will occur before other strings in the index so if you are sorting a field with both numbers and strings (like a title field which might have "24" and "Prison Break") then the sort_field will think it is sorting integers when it really should be sorting strings.
Note 2: When sorting by integer, integers are only 4 bytes so anything larger will cause strange sorting behaviour.
SCORE | = | Data_Wrap_Struct(cSortField, NULL, &frt_deref_free, (SortField *)&SORT_FIELD_SCORE) |
SCORE_REV | = | Data_Wrap_Struct(cSortField, NULL, &frt_deref_free, (SortField *)&SORT_FIELD_SCORE_REV) |
DOC_ID | = | Data_Wrap_Struct(cSortField, NULL, &frt_deref_free, (SortField *)&SORT_FIELD_DOC) |
DOC_ID_REV | = | Data_Wrap_Struct(cSortField, NULL, &frt_deref_free, (SortField *)&SORT_FIELD_DOC_REV) |
Create a new SortField which can be used to sort the result-set by the value in field field.
:type: | Default: +:auto+. Specifies how a field should be sorted. Choose from one of; +:auto+, +:integer+, +:float+, +:string+, +:byte+, +:doc_id+ or +:score+. +:auto+ will check the datatype of the field by trying to parse it into either a number or a float before settling on a string sort. String sort is locale dependent and works for multibyte character sets like UTF-8 if you have your locale set correctly. |
:reverse Default: false. Set to true if you want to reverse the
sort.
Return true if the field is to be reverse sorted. This attribute is set when you create the sort_field.
Return the type of sort. Should be one of; +:auto+, +:integer+, +:float+, +:string+, +:byte+, +:doc_id+ or +:score+.