Sam and Yaron,

I'm trying to implement the inverse of PartOf (ComposedOf) as discussed on this list a few days ago (also at end of this email). I'm using Cargo, PageSchemas, and PageForms. My understanding is that ComposedOf would not be part of the schema, but would be a manual edit to the automatically generated template for the Place category. Below is the template code with the manual edits in color. The first "_pageName" refers to data in Cargo tables. The second "_pageName" is the current page being displayed, which I don't know how to specify in this context. This code results in no error and no text after the "ComposedOf" label. When viewing the place "Sol System", the ComposedOf text should include links to Earth and Mars, since they are both currently in the Place table as PartOf the Sol System. In this context, the second _pageName should return "Sol System" (or "Sol_System" ?).

{{#template_params:Type|PartOf (label=Part Of)|ComposedOf}}
{{#cargo_declare:_table=Place|Type=Page (allowed values=SolarSystem,AsteroidBelt,Asteroid,Planet,WaterBody,Continent,GeographicEntity,Nation,SubNationalRegion,City,Neighborhood,Street,Building,Room)|PartOf=Page|ComposedOf={{#cargo_query:table=Place|fields=Place._pageName|where = PartOf HOLDS "_pageName"}}}}

I pushed on "Recreate Data" in the Template menu, which may explain how "ComposedOf" got added to the table. I did not add ComposedOf to the schema.
Here is the Place table:

Page Type PartOf ComposedOf
Earth Planet Sol System
Mars Planet Sol System
Sol System SolarSystem


On Mon, Aug 30, 2021 at 9:11 PM Sam Wilson <> wrote:

I think the normal way to do this in Cargo would be not to have the inverse property stored in a page's data, but rather to query the inverse wherever required. So, for example, an Idaho page would define part_of as USA, and then on the USA page you could have a template that displays all the composed_of pages: {{#cargo query: tables = places | where = part_of HOLDS 'USA' }}. This way, there's no double-entry of values and so nothing to get out of sync.

On 31/8/21 6:42 am, David Epstein wrote:
If a class has a composed_of property and a part_of property, can I define these somewhere as inverse relationships? I'd like to set Idaho as part_of the USA and then (automatically) see that assignment in USA's composed_of list?

Moreover, is it possible to specify that the properties have a more specific domain, not just any page but only pages from the category "Place"?

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