WebApps 2

Error handling

An error object from the data storage API consists of the following:

{
   dataStore: "datastorekey",
   type: "An error type",
   message: "An error message"
}

The following error types exist

Type	What went wrong?
`validation_failed`	Input arguments failed to validate. See the error message for more information
`read_only`	It is not possible to perform mutating operations when a data store is set to read-only
`item_not_found`	A non-existing key was used to retrieve data
`item_property_count_exceeded`	Too many properties on the retrieved item. See restrictions
`illegal_method_call`	Most likely was next() called on an exhausted search result iterator
`unknown`	An unknown error occurred. See the error message for more information

Restrictions

The data storage API is available in WebApps and RESTApps.
Data stored in a data store must be be JSON serializable
A data store record is restricted to a maximum of 50 top level properties
- A record is the the value in a key-value data store or an item in a collection data store
- If property count is exceeded, record will be unavailable. Properties can be removed by setting it to null
Top level property keys are restricted to a maximum of 100 characters
Property values are restricted to a maximum of 5000 characters
- A value is the data stored on a top level property
Keys dsid and dstimestamp are populated by the API itself (i.e. never try to mutate/store data for such key since your data/value will be overwritten by the API).
- Keys dsid and dstimestamp are internal values and may change at any time.
- The values of dsid and dstimestamp should NOT be used as identifiers. They will change, for instance, if the website is exported and imported.
- If there is a need for persistant keys or timestamps, for instance to connect posts in 2 separate datastores, set up custom fields as unique keys for this purpose.