External Data Source Validation
Index and Batch fields can be automatically validated against an external data source (SharePoint) by assigning a SharePoint field type to that field. If validation fails, the operator is required to select or provide a valid value.
Any external field type is validated against its data source at runtime. Validation against columns in data sources such as SharePoint requires access to the data source server. Consequently, the operator must be able to log into the server either before or during the validation or verification process. Integrated authentication will be attempted, but if this fails the operator will be presented with a web login form. The operator cannot validate the document without proper access rights.
Depending on the external field type settings in the
External Field Type
Properties window in the
Administration
module, fields linked to the external data source may be displayed in the
SharePoint Validation
window or in the field panel. The new window
only appears if the field fails validation and if the number of choices is
greater than the value specified in the
Administration
module. Managed Metadata and Enterprise Keywords fields may also include
the hierarchy path in brackets next to each term. This can assist the user in
resolving ambiguous terms and provide more information on the location of the
term in the store.
Caching
Caching is used to minimize round trips to SharePoint. This cache is stored in memory and is not persistent. You can specify individual limits for Managed Metadata term sets, Enterprise Keywords terms, and lookup results via a new section in the ACConfig.xml file in the <SharePoint> element. You can also specify expiration times (in minutes) for each individual value. Unused values will be removed from the cache when the expiration time has elapsed. Each time a value is used, the expiration timer is reset to zero. Sample:
<TermsetCache>
<MaxValues>100</MaxValues>
<Lifetime>60</Lifetime>
</TermsetCache>
<TermsCache>
<MaxValues>10000</MaxValues>
<Lifetime>60</Lifetime>
</TermsCache>
<LookupCache>
<MaxValues>1000</MaxValues>
<Lifetime>60</Lifetime>
</LookupCache>
Caching can be disabled by setting all the <MaxValues> to zero.
During validation the cache is always checked first. If a matching value is not found, the SharePoint server is queried. If the value is found on the server, it is stored in the cache. If the cache threshold is reached, the least recently used items are removed from the cache to make room for new values.