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


What went wrong?


Input arguments failed to validate. See the error message for more information


It is not possible to perform mutating operations when a data store is set to read-only


A non-existing key was used to retrieve data


Too many properties on the retrieved item. See restrictions


Most likely was next() called on an exhausted search result iterator


An unknown error occurred. See the error message for more information


  • 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.