Struct xmp_toolkit::XmpMeta

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pub struct XmpMeta { /* private fields */ }

Expand description

The XmpMeta struct allows access to the XMP Toolkit core services.

You can create XmpMeta structs from metadata that you construct, or that you obtain from files using the XmpFile struct.

Implementations

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impl XmpMeta

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pub fn new() -> XmpResult<XmpMeta>

Creates a new, empty metadata struct.

An error result from this function is unlikely but possible if, for example, the C++ XMP Toolkit fails to initialize or reports an out-of-memory condition.

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pub fn from_file<P: AsRef<Path>>(path: P) -> XmpResult<Self>

Reads the XMP from a file without keeping the file open.

This is a convenience function for read-only workflows.

Arguments

path: Path to the file to be read

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pub fn register_namespace(
namespace_uri: &str,
suggested_prefix: &str
) -> XmpResult<String>

Registers a namespace URI with a suggested prefix.

If the URI is not registered but the suggested prefix is in use, a unique prefix is created from the suggested one. The actual registered prefix is returned. It is not an error if the URI is already registered, regardless of the prefix.

Arguments

namespace_uri: The URI for the namespace. Must be a valid XML URI.
suggested_prefix: The suggested prefix to be used if the URI is not yet registered. Must be a valid XML name.

Returns the prefix actually registered for this URI.

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pub fn property(&self, schema_ns: &str, prop_name: &str) -> Option<String>

Gets a property value.

When specifying a namespace and path (in this and all other accessors):

If a namespace URI is specified, it must be for a registered namespace.
If the namespace is specified only by a prefix in the property name path, it must be a registered prefix.
If both a URI and path prefix are present, they must be corresponding parts of a registered namespace.

Arguments

schema_ns: The namespace URI for the property. The URI must be for a registered namespace. Must not be an empty string.
prop_name: The name of the property. Can be a general path expression. Must not be an empty string. The first component can be a namespace prefix; if present without a schema_ns value, the prefix specifies the namespace. The prefix must be for a registered namespace, and if a namespace URI is specified, must match the registered prefix for that namespace.

Error handling

Any errors (for instance, empty or invalid namespace or property name) are ignored; the function will return None in such cases.

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pub fn set_property(
 &mut self,
 schema_ns: &str,
 prop_name: &str,
 prop_value: &str
) -> XmpResult<()>

Creates or sets a property value.

This is the simplest property setter. Use it for top-level simple properties.

Arguments

schema_ns: The namespace URI; see XmpMeta::property().
prop_name: The name of the property. Can be a general path expression. Must not be an empty string. See XmpMeta::property() for namespace prefix usage.
prop_value: The new value.

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pub fn set_property_date(
 &mut self,
 schema_ns: &str,
 prop_name: &str,
 prop_value: &XmpDateTime
) -> XmpResult<()>

Creates or sets a property value using an XmpDateTime structure.

This is the simplest property setter. Use it for top-level simple properties.

Arguments

schema_ns: The namespace URI; see XmpMeta::property().
prop_name: The name of the property. Can be a general path expression. Must not be an empty string. See XmpMeta::property() for namespace prefix usage.
prop_value: The new value.

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pub fn does_property_exist(&self, schema_ns: &str, prop_name: &str) -> bool

Reports whether a property currently exists.

Arguments

schema_ns: The namespace URI; see XmpMeta::property().
prop_name: The name of the property. Can be a general path expression. Must not be an empty string. See XmpMeta::property() for namespace prefix usage.