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What are the advanced functions that I can use in the Mandatory Fields of my link resolver?

The following functions can be used to manipulate when a link should appear. If any of them result in a value (not an empty string), then the link will appear:


Function Description
IfNotEmpty(expr1,expr2,expr3) If expr1 is not empty, it returns expr2. If expr1 is empty and expr3 is present it returns expr3. In all other cases it returns empty string.
CustomerLocalsLookup(expr1,epxr2) Searches for ISSN expr1 in the customer collection expr2
IfEqual(expr1,expr2,expr3) Returns expr3 if expr1 is equal to expr2. Returns empty string otherwise.
IfEqualIgnoreCase(expr1,expr2,expr3) The same as IfEqual, except the comparison is ignoring the case
UrlEncode(expr1) Returns URLEncoded expr1
CheckDate(Date,FromDate,ToDate,StringToReturn) Returns StringToReturn if Date is between ToDate and FromDate.
ToDate and FromDate can be empty.

Input field expected to be a Date field in the form of YYYY, YYYYMM, YYYYMMDD.
An empty FromDate is open ended (e.g. = 0)

An empty ToDate is open ended (e.g. treat as 99999999)
CheckEmbargo(Date,Embargo,StringToReturn) Returns StringToReturn if Date is not covered by Embargo.

Input field expected to be a Date field in the form of YYYY, YYYYMM, YYYYMMDD.

Embargo can be a number or a number following by a single letter d, m or y.

The number without a letter specifies number of days.

The number followed by m - number of month.

The number followed by y - number of years.
Example: 10, 10d, 12m, 1y



  • {IfNotEmpty({AUTHOR},AU={AUTHOR},{ISBN})} - returns AU= if author field exist, or empty string otherwise.

  • {IfNotEmpty({IfEqual({DBCODE},catXXXXXa,ok)},,ok)},{JOURNAL} - Show this link if the record IS a journal article AND if the database of the record is NOT my catalog. catxxxxxa is the name of your institution's catalog which can be found for your Discovery Service profile in the Databases sub-tab of EBSCOadmin.

  • {CustomerLocalsLookup({ISSN},webed)} - returns call number for the article using the custid.webed collection

    {IfEqual({DBCODE},afh)} - if this expression is entered in the Mandatory field list, the link will appear only for articles from afh

  • {CheckDate({DATE},2002,2004,OK)} - returns "OK" if the article was published between 2002 and 2004.

    {CheckEmbargo({DATE},2y,{ISSN})} - returns ISSN of the article if the article was published more then 2 years ago.


Related Terms: custom link, custom linking, custom links, customlinking, customlink, customlinks