Capture of terms through an authority file or by using terminology previously entered into the database.
Through this option terms can be captured by using another database, for example, an authority database, or by using the same database, in order to standardise the authors, descriptors, editors, etc.
Access to the associated database of terms is made through the inverted list. Consequently sub-dictionaries must be defined inside the terms dictionary, by means of the prefixes to the indexed fields.
Through the prefix indicated in the FDT you can access the postings of the key, obtaining the Mfn of the record. The MFN of the first key posting is used to access the record, after which two formats are applied:
The display format is applied to the record obtained through the posting in order to determine how the format will be displayed in the field selection list being displayed to the user, while the extraction format is used to extract the field and transfer it to the record. The list is built with the element <select> from HTML language and the options of the selection menu are completed as shown below:
<option value="extraction format">display format</option>
Then, when the user clicks on a term, the link associated with the extraction format is transferred to the record.
The formats mentioned can have all the complexity of the format language for the construction of CDS/Isis. For very complicated formats, placing a previously built format as the extraction format (PFT) is recommended, using the form @xxxxxx.pft to incorporate the format where it is required. In this case the extraction format and the display format are included in the @xxxxxx.pft format, separated with $$$. The select statement from the formatting language should be used to apply the format accurately to the ID of the recovered field in the inverted list.
Example:
select e3
case 1: v1
case 100: v100^a,`$$$`v100^a
case 600: v600^a,`$$$`v600^a
case 700: v700^a,`$$$`v700^a
case 110: v110^a,`$$$`v110
case 111: v111^a,`$$$`v111
case 245: v245^a,`$$$`f(mfn,1,0)
case 260: v260^a," : "v260^b,`$$$`v260
case 270: v270
case 340: v340
...
...
endsel
The variable associated to the case, identifies the ID allocated to the field in the FST; then the format to be used for the display of the field in the selection list is specified and next, preceded by '$$$', the format used to display the field and to transfer it to the input form. If the extraction format is omitted, the display format is used as an extraction format.
The field ID is retrieved through the posting obtained by using the prefix. Therefore, it is possible to display a selection list that includes several fields, for example, all the personal authors of the Marc format (100,600,700).
In this case, all the fields will be indexed with the same prefix, but the ID should be the same as the field tag for correct extractions from the data base, when applying the corresponding extraction format.
For example, according to the extraction format (@xxxxx.pft) previously shown, to display all the authors in MARC format, the FST for the indexing will specify:
100 0 "AU_"v100^a/
600 0 (| AU_| v600^a|%|/)
700 0 (| AU_| v700^a|%|/)
Note the usage of the % in the case of repeatable fields to generate the number of occurrences, since the presentation of the lists uses the posting component to identify the number of occurrences used to extract the field correctly.