Hi Ben, Do you know if there is any scope or plan for supporting transactions in app-schema? I doubt if it's possible to do this at all. Here is an example: Let's say each Feature can have multiple multilingual Names. The database would look like this: Feature (Feature_id, Shape) Name (Name_id, Feature_id, Lang_id, Name) Lang (Lang_id, Language)
Let's say we don't expose Name_id and Lang_id (as they are auto-generated). Also, assume Lang table is pre-populated with all possible languages, and thus should not be editable. In this case, when a WFS addFeature request comes to Geoserver (with Shape, Language(s), Name(s)). In this case, we should not be creating a Lang entry. Instead, the Lang_id should be figured out using Language, used to create a new entry in Name table (of course, taking care that the generated Feature_id is added to it). Also, in some cases we need to respect unique constraints like there can be only 1 name per language for each feature. I doubt if XSLT can handle such use cases. I think an extension where these rules can be configured could solve this problem (but this configuration can get quite complex, mimicking a database itself). Please let me know your thoughts on this. Thanks, Sunil On Tuesday 21 February 2012 12:22:06 PM IST, Ben Caradoc-Davies wrote: > > On 21/02/12 10:40, Sunil Padda wrote: >> >> We want to be able to do both read& write to the underlying database. >> As app-schema gives a read-only view of the data, this doesn't suit our >> needs. Is there any work in progress for the future to enable >> app-schema to support writes? (As I understand, it's not possible. But, >> I would like to confirm). > > > Correct. app-schema does not yet support transactions (and in the > GeoServer world, it does not support WFS-T). > > One missing piece is the parsing of complex feature GML into GeoTools > objects. There is a third-party implementation based on GeoTools but it > has not yet been contributed. Some of my colleagues are currently in > communication with the authors. My colleagues aim to get GeoTools > consuming complex GML. This would likely be of *great* assistance to you. > >> >> I didn't look at the app-schema code yet, but is there any code in >> app-schema that we could potentially leverage when building a custom >> solution (maybe something like ComplexFeatureType, ComplexFeature, >> ComplexFeatureBuilder etc.). > > > Potentially. These are just FeatureTypeImpl and FeatureImpl. There is > not yet any builder (Andrea has justifiably complained about this); > building complex features is rather tricky as it refers to external > schemas and circular relationships between types. Please have a look at > the many app-schema unit tests. > >> >> One last question. Assuming we somehow build our own custom solution to >> create complex features, does GeoServer support reads and writes from >> it? If not, are there any other WFS servers that do? > > > Sorry, I don't know. > > Kind regards, > ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ GeoTools-GT2-Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
