ohvbd uses a number of internal attributes to track data states within pipelines.
Generally these are not designed to be user-modified. They are, however, listed here for completeness (and curiosity).
It is typically not a good idea to manually modify these attributes directly unless a helper such as force_db() or ohvbd_db() is provided.
Even then, modifying these attributes may cause unexpected errors or data inconsistencies. These errors may not be signalled to the user by ohvbd, and they may not be obvious or even detectable.
Be sure when modifying the db attribute that the value you set it to is consistent with the origin of your data, and that the value is a db known to ohvbd.
Summary table of attributes
| Attribute | Description | Object/s | |
| db | The database from which the object has been retrieved. | ohvbd.ids, ohvbd.responses, ohvbd.data.frame, ohvbd.ad.matrix | |
| metric | The AD metric. | ohvbd.ad.matrix | |
| gid | The AD aggregation level. | ohvbd.ad.matrix | |
| cached | Whether the data was loaded from a cache. | Any | |
| writetime | The time at which a data file was originally cached. | Any | |
| query | The search query sent to the Hub. | ohvbd.hub.search | |
| searchparams | Any extra parameters sent to the Hub. | ohvbd.hub.search |
Note: (AD = AREAdata)
db
Type: string
The db attribute indicates to ohvbd where an object originated.
It is used to determine appropriate method dispatch (such as with fetch()) and to check that pipelines are sensible constructed.
metric
Type: string
metric signifies what AD metric the matrix contains. It is predominantly (but not exclusively) used for formatting and caching.
gid
Type: integer
gid represents the spatial scale of data from AD. It is used for a variety of spatial operations.
cached
Type: boolean
cached objects receive this flag at write-time. It sticks with the object when it is reloaded, and is mostly used for UI/UX purposes.
writetime
Type: POSIXct
writetime stores the time at which a cached object (that is likely to become stale) was written to the cache.
searchparams
Type: named list
A record of any other search parameters that were sent to the vbdhub search API (e.g. species IDs etc.).