magpie.permissions

Module Contents

Classes

Permission	Applicable Permission values (names) under certain Service and Resource.
PermissionType	Applicable types of Permission according to context.
Access	Applicable access modifier of Permission values.
Scope	Applicable access modifier of Permission values.
PermissionSet	Explicit definition of a Permission with applicable Access and Scope to resolve it.

Functions

format_permissions(permissions: Optional[Collection[AnyPermissionType]], permission_type: Optional[PermissionType] = None, force_unique: bool = True) → Dict[(Str, Union[List[Str], PermissionObject, Str])]

Obtains the formatted permission representations after validation that each of their name is a known member of

magpie.permissions.PERMISSION_REASON_DEFAULT = no-permission

magpie.permissions.PERMISSION_REASON_MULTIPLE = multiple

magpie.permissions.PERMISSION_REASON_ADMIN = administrator

class magpie.permissions.Permission

Bases: magpie.utils.ExtendedEnum

Applicable Permission values (names) under certain Service and Resource.

READ = read

WRITE = write

ACCESS = access

BROWSE = browse

GET_CAPABILITIES = getcapabilities

GET_MAP = getmap

GET_FEATURE_INFO = getfeatureinfo

GET_LEGEND_GRAPHIC = getlegendgraphic

GET_METADATA = getmetadata

GET_FEATURE = getfeature

DESCRIBE_FEATURE_TYPE = describefeaturetype

DESCRIBE_PROCESS = describeprocess

EXECUTE = execute

LOCK_FEATURE = lockfeature

TRANSACTION = transaction

class magpie.permissions.PermissionType

Bases: magpie.utils.ExtendedEnum

Applicable types of Permission according to context.

ACCESS = access

ALLOWED = allowed

APPLIED = applied

DIRECT = direct

INHERITED = inherited

EFFECTIVE = effective

OWNED = owned

class magpie.permissions.Access

Bases: magpie.utils.ExtendedEnum

Applicable access modifier of Permission values.

ALLOW = allow

DENY = deny

class magpie.permissions.Scope

Bases: magpie.utils.ExtendedEnum

Applicable access modifier of Permission values.

MATCH = match

RECURSIVE = recursive

class magpie.permissions.PermissionSet(permission: magpie.typedefs.AnyPermissionType, access: Optional[Union[Access, Str]] = None, scope: Optional[Union[Scope, Str]] = None, typ: Optional[PermissionType] = None, reason: Optional[Str] = None)

Bases: object

Explicit definition of a Permission with applicable Access and Scope to resolve it.

The Permission is the name of the applicable permission on the magpie.models.Resource. The Scope defines how the Permission should impact the resolution of the perceived Effective Permissions over a magpie.models.Resource tree hierarchy. The Access defines how the Permission access should be interpreted (granted or denied).

Optionally, a PermissionType can be provided to specifically indicate which kind of permission this set represents. This type is only for informative purposes, and is not saved to database nor displayed by the explicit string representation. It is returned within JSON representation and can be employed by Effective Permissions resolution to be more verbose about returned results.

On missing Access or Scope specifications, they default to Access.ALLOW and Scope.RECURSIVE to handle backward compatible naming convention of plain permission_name.

Initializes the permission definition, possibly using required conversion from other implementations.

Parameters

• permission – Name of the permission, or any other implementation from which the name can be inferred.

• access – Effective behaviour of the permissions. Generally, grant or deny the specified permission.

• scope – Scope for which the permission affects hierarchical resources. Important for effective resolution.

• typ – Type of permission being represented. Informative only, does not impact behavior if omitted.

• reason – Slightly more indicative information on why the current permission-type has this value. Value should be either explicitly provided or will be inferred if converted from input PermissionTuple.

See also

PermissionSet._convert()

__slots__ = ['_name', '_access', '_scope', '_tuple', '_type', '_reason']

permission

__eq__(self: Any, other) → bool

Return self==value.

__ne__(self: Any, other) → bool

Return self!=value.

__lt__(self: Any, other) → bool

Ascending sort of permission according to their name, access and scope modifiers.

First sort by permission name alphabetically, followed by increasing restrictive access and increasing range of scoped resources.

Using this sorting methodology, similar permissions by name are grouped together first, and permissions of same name with modifiers are then ordered, the first having less priority when selecting a single item to display with conflicting possibilities. Respecting Access.DENY is more important than Access.ALLOW (to protect the Resource), and Scope.MATCH is closer to the actual Resource than Scope.RECURSIVE permission received from a farther parent in the hierarchy.

Explicitly, sorted explicit string representation becomes:

[name1]-[allow]-[match]
[name1]-[allow]-[recursive]
[name1]-[deny]-[match]
[name1]-[deny]-[recursive]
[name2]-[allow]-[match]
[name2]-[allow]-[recursive]
[name2]-[deny]-[match]
[name2]-[deny]-[recursive]
...

We then obtain two crucial ordering results:

1. We can easily pick the last sorted item with highest resolution priority to find the final result of corresponding permissions. (note: final result for same user or group, their direct/inherited resolution is not considered here).

2. Picking the first element with lowest priority also displays the permission that impacts the widest range of resources. For instance in Magpie UI, indicating that a permission as Scope.RECURSIVE is more verbose as it tell other resources under it are also receive the specified Access modifier rather than only the punctual resource.

Warning

Alphabetically sorting permissions by string representation (implicit/explicit) is not equivalent to sorting them according to Permission priority according to how modifiers are resolved. To obtain the prioritized sorting as strings, a list of PermissionSet (with the strings as input) should be used to convert and correctly interpreted the raw strings, and then be converted back after sorting.

# valid priority-sorted strings
[str(perm) for perm in sorted(PermissionSet(p) for p in permission_strings)]

# not equivalent to raw sorting
list(sorted(permission_strings))

__hash__(self) → int

Return hash(self).

__str__(self) → magpie.typedefs.Str

Obtains the compound literal representation of the PermissionSet.

Employed for database storage supporting ziggurat format.

__repr__(self) → magpie.typedefs.Str

Obtains the visual representation of the PermissionSet.

like(self, other)

Evaluates if one permission is similar to another permission definition regardless of modifiers.

This is different than == operator which will evaluate exactly equal permission definitions.

json(self) → magpie.typedefs.PermissionObject

Obtains the JSON representation of this PermissionSet.

ace(self: Optional[Union[models.User, models.Group]], user_or_group) → magpie.typedefs.AccessControlEntryType

Converts the PermissionSet into an ACE that pyramid can understand.

property reason(self) → Optional[Str]

Indicative reason of the returned value defined by type() or inferred by the PermissionTuple.

See also

combine()

Returns

Single string that describes the reason (source) of the permission, or multiple strings if updated by combination of multiple permissions.

classmethod resolve(cls, permission1: magpie.typedefs.ResolvablePermissionType, permission2: magpie.typedefs.ResolvablePermissionType, context: magpie.permissions.PermissionType = PermissionType.INHERITED, multiple_choice: Optional[ResolvablePermissionType] = None) → magpie.typedefs.ResolvablePermissionType

Resolves provided permissions into a single one considering various modifiers and groups for a resource.

Permissions MUST have the same Permission name.

By default (using same_resources), the associated Resource on which the two compared permissions are applied on should also be the same (especially during local Inherited Permissions resolution). This safeguard must be disabled for Effective Permissions that specifically handles multi-level Resource resolution.

The comparison considers both the Access and Scope of Inherited Permissions of the User, as well as its Group memberships sorted by their priority.

See also

• magpie.services.ServiceInterface.effective_permissions()

• magpie.api.management.users.user_utils.combine_user_group_permissions()

• PermissionSet.__lt__()

property group_priority(self) → Optional[GroupPriority]

Priority accessor in case of group inherited permission resolved by PermissionTuple.

property perm_tuple(self) → Optional[PermissionTuple]

Get the original PermissionTuple if available (PermissionSet must have been created by one).

property implicit_permission(self) → Optional[Str]

Obtain the implicit string representation of the PermissionSet as plain Permission name.

This representation is backward compatible with prior versions of Magpie where explicit representation of permission names in the database did not exist.

If the contained modifiers of the PermissionSet (notably the Access.DENY) result in a string representation that is not possible according to non existing permissions for older Magpie instances, the returned value will be None.

See also

• explicit_permission() for the new representation.

property explicit_permission(self) → magpie.typedefs.Str

Obtain the explicit string representation of the PermissionSet.

This format is always guaranteed to be completely defined contrary to implicit_permission().

See also

• __str__() (default string value).

• implicit_permission() for the old representation.

property name(self) → magpie.permissions.Permission

property access(self) → magpie.permissions.Access

property scope(self) → magpie.permissions.Scope

property type(self) → Optional[PermissionType]

classmethod _convert(cls: magpie.typedefs.AnyPermissionType, permission) → Optional[PermissionSet]

Converts any permission representation to the PermissionSet with applicable enum members.

Supports older Permission representation such that implicit conversion of permission name without access and scope values are padded with defaults. Also, pre-defined partial or full definition from literal string representation are parsed to generate the PermissionSet instance.

Parameters

permission – implicit or explicit permission name string, or any other known permission implementation

Raises

ValueError – when the permission name cannot be identified or parsed

magpie.permissions.format_permissions(permissions: Optional[Collection[AnyPermissionType]], permission_type: Optional[PermissionType] = None, force_unique: bool = True) → Dict[Str, Union[List[Str], PermissionObject, Str]]

Obtains the formatted permission representations after validation that each of their name is a known member of Permission enum, and optionally with modifiers as defined by PermissionSet.

The returned lists are sorted alphabetically by permission name, and then in order of resolution priority (from highest to lowest) for each subset or corresponding name.

The permissions are cleaned from any duplicate entries, unless force_unique is specified to allow it. If no or empty permissions is provided, empty lists are returned.

Note

Field permission_names provides both the older implicit permission names and the newer explicit name representation. For this reason, there will be semantically “duplicate” permissions in that list, but there will not be any literal string duplicates. Implicit names are immediately followed by their explicit name, unless implicit names do not apply for the given permission (e.g.: when Access.DENY did not exist). Only detailed and explicit JSON representations are provided in the permissions list.

When permission_type is equal to PermissionType.ALLOWED, the collection of every applicable PermissionSet is automatically generated by expanding all combinations of Access and Scope with every provided Permission name in permissions. This allows more concise definition of allowed permissions under magpie.services.Services and their children Resource by only defining Permission names without manually listing all variations of PermissionSet.

For other permission_type values, which represent Applied Permissions only explicitly provided permissions are returned, to effectively return the collection of active permissions.

Parameters

• permissions – multiple permissions of any implementation and type, to be rendered both as names and JSON.

• permission_type – indication of the represented permissions to be formatted, for informative indication.

• force_unique – whether to remove duplicate entries by association of name, access and scope or not.

Returns

JSON with the permissions listed as implicit+explicit names, as permission set objects, and their type.