OpenSlides Meta Repository

This shared repository holds all relevant (meta) data. Other services may include it as a sub-repository to have access to its data.

Collections

The datastructure of OpenSlides is defined by a list of collections. For each collection, there is a file in the collections directory. The file collection-meta.yml contains meta fields, that are used by more then one collection.

Each collection-file has the following format:

• Model level settings:
  • unique_together and unique_together_strict define groups of fields for which UNIQUE constraints will be generated in the database. Difference: for unique_together the uniqueness check is skipped if value in at least one of the fields is NULL.
• Length of names:
  • field name: Their length is limited to 25 characters. There are still some fields with longer names, that has to be shortened
• Types:
  • Nativ datatypes: text, string (text with maxLength=256), number, boolean, JSON
  • HTMLStrict: A string with HTML content.
  • HTMLPermissive: A string with HTML content (with video tags).
  • float: Numbers that are expected to be non-integer. Formatted as in rfc7159.
  • decimal(X): Decimal values represented as a string with X decimal places. At the moment we support only X == 6.
  • timestamp: Datetime as a utc datetime object.
  • timezone: Text field with the constraint that the content must be a valid timezone string as far as the postgres database is concerned. (i.e. the name values from postgres-inbuilt view pg_timezone_names)
  • []: This indicates and arbitrary array of the given type. At the moment we support only some types. You can add JSON Schema properties for items using the extra property items
  • color: string that must match ^#[0-9a-f]{6}$
• Relations:
  • We have the following types: relation, relation-list, generic-relation and generic-relation-list.
  • Non-generic relations: The simple syntax for such a field to: <collection>/<field>. This is a reference to a collection. The reverse relation field in this collection is . E. g. in a motion the field category_id links to one category where the field motion_ids contains the motion id. The simple notation for the field is motion_category/motion_ids. The reverse field has type relation-list and is related back to motion/category_id. The type indicates that there are many motion ids.
  • Generic relations: The difference to non-generic relations is that you have a list of possible fields, so to can either hold multiple collections (if the field name is the same): to: collections: - agenda_item - assignment - ... field: tag_ids Or to can be a list of collection fields: to: - motion/option_ids - user/option_$_ids
  • on_delete: This fields determines what should happen with the foreign model if this model gets deleted. Possible values are: - SET_NULL (default): delete the id from the foreign key - PROTECT: if the foreign key is not empty, throw an error instead of deleting the object - CASCADE: also delete all models in this foreign key
• JSON Schema Properties:
  • You can add JSON Schema properties to the fields like enum, description, items, maxLength, minimum and maximum.
• Additional properties:
  • The property read_only describes a field that can not be changed by an action.
  • The property default describes the default value that is used for new objects.
  • The property required describes that this field can not be null or an empty string. If this field is given it must have some content. On relation and generic-relation fields the value as to be an id of an existing object.
  • The property equal_fields describes fields that must have the same value in the instance and the related instance.
  • The property constant describes fields values in which can not be updated once set (protected by batabase constraint).
  • The property constant_legacy describes fields that should be protected from being changed inside of the regular external actions (logic should be defined in the services).
  • The property sql is used in read‑only relational fields to define a custom SQL query for calculating the field’s value. Must be used together with log_triggers.
  • The property log_triggers contains a list of rules describing when changes in the database should trigger log entries for this calculated relational field. For each select statement of sql define a rule with:
    • on_table: the table whose changes affect the calculated value.
    • on_columns (optional): columns in on_table that affect the calculated value. Omit this if all relevant fields have constant: true or if on_table is an intermediate table.
    • log_collection_id_column or log_collection_id_sql: how to get the id of the calculated field's collection for the log entry:
      • Use log_collection_id_column for direct access from the instance of on_table.
      • Use log_collection_id_sql when id must be fetched from another table.
    • log_value_column or log_value_sql: how to get the id added to the calculated field result or deleted from it (depending on the operation type):
      • Use log_value_column for direct access from the instance of on_table.
      • Use log_value_sql when the value must be retrieved from another table.
• Restriction Mode: The field restriction_mode is required for every field. It puts the field into a restriction group. See https://github.com/OpenSlides/OpenSlides/wiki/Restrictions-Overview