1   Basic field types

• String Field -- A string

• Password Field -- A password

  The difference from a string is that there could be restrictions on the way this field is read, because passwords may be stored hashed or nor readable at all.

• StringList Field -- A list of strings

• Int Field -- An integer

• Long Field -- A long

• Float Field -- A float

• DateTime Field -- A DateTime

• File Field -- A File object

• Image Field -- An Image object

2   Basic field properties

Fields are configured using the following properties.

• default_expr -- Default value expression

  The default value for this field at creation time. It is also used if the attribute is not found on an object when it is accessed, this can happen on an old instances if its schema is edited later. In the expression the following namespace is available:

  • datamodel: the datamodel
  • field: the current field
  • user: the current user
  • portal: the portal
  • DateTime: a DateTime constructor
  • nothing: None

• is_indexed -- Indexed in SearchableText

  If true the field is indexed in SearchableText. This only has meaning for String and String List fields.

• acl_read_permissions -- ACL: Read permissions

  A ';'-separated list of permissions. If not empty, the user must have at least one of the permissions on the object to have read access to the field.

• acl_read_roles -- ACL: Read roles

  A ';'-separated list of roles. If not empty, the user must have at least one of the roles on the object to have read access to the field.

  When dealing with member directory entries, the user is deemed to have the role 'Owner' if the entry in question is his.

• acl_read_expr -- ACL: Read expression

  A TALES expression which returns a boolean describing on what condition read access to the field is allowed. In the expression the following namespace is available:

  • datamodel: the datamodel
  • field: the current field
  • user: the current user
  • roles: the current user's roles
  • context: the context (the container in creation mode) (the directory for directory entries)
  • proxy: the proxy (None in creation mode)
  • dir: an alias for the context
  • nothing: None

• acl_write_permissions -- ACL: Write permissions

• acl_write_roles -- ACL: Write roles

• acl_write_expr -- ACL: Write expression

  Conditions to have write access to the field. See the read access description above.

• read_ignore_storage -- Read: ignore storage

  If true, nothing is actually read from the storage (object or directory entry). The default value or the 'read expression' will be used.

• read_process_expr -- Read: expression

  If not empty, the value read from the storage is further processed through this TALES expression. The expression's return value is what the rest of CPSSchemas will see. The following namespace is available:

  • value: the value that was really read from the storage
  • data: a mapping of the values read from the storage for this entry
  • field: the current field
  • user: the current user
  • portal: the portal
  • proxy: the potentially associated proxy
  • object: the context object
  • DateTime: a DateTime constructor
  • nothing: None
  • context: deprecated, use the "object" key instead

  Note that the context object is the object on which the read is being done, it is not the proxy (in the case of attribute storage).

• read_process_dependent_fields -- Read: expression dependent fields

  If the above expression uses some other fields, they must be specified here so that the back-end knows what to fetch when a re-computation is done.

• write_ignore_storage -- Write: ignore storage

  If true, nothing will actually be written to the storage.

• write_process_expr -- Write: expression

  If not empty, the written value will be processed though this TALES expression before being really written to the storage. The same namespace than for 'read_process_expr is available, except that 'value' and 'data' refer to the value as seen by the rest of CPSSchemas before writing.

3   Additional properties

Some specific fields have additional properties beyond the basic ones, to configure their specific behavior.

• File Field

  • suffix_text -- Suffix for field containing Text conversion

    Describes which String Field will hold the text conversion.

  • suffix_html -- Suffix for field containing HTML conversion

    Describes which File Field will hold the HTML conversion.

    These two properties, if not empty, define the id of another field of the schema (derived from the id of the current field by adding the specified suffix) that will store an automatically generated conversion to text or HTML.

    The conversion is currently done using the PortalTransforms framework.

• Disk File Field

  This field stores the file on the disk instead of in the ZODB.

  • disk_storage_path -- path relative to $INSTANCE_HOME for file storage.

    If this path is not set, it will check if portal_schemas has a disk_storage_path property. If neither is set then var/files will be used.