Table of Contents

Class XmpData

Namespace
Egami.Metadata
Assembly
Egami.dll

A parsed XMP packet: its properties by namespace URI and local name, each a simple value, an XmpArray or an XmpStruct, with typed getters and setters for what apps ask for most (Dublin Core, XMP Basic, Photoshop and TIFF properties). An unedited packet writes back byte for byte; an edited one is written as canonical RDF/XML with padding, keeping every property it does not know, qualifiers included.

public sealed class XmpData : XmpStruct
Inheritance
XmpData
Inherited Members

Examples

XmpData xmp = new()
{
    Title = "Harbour at dawn",
    Creators = ["A. Photographer"],
    Keywords = ["harbour", "Bergen"],
    Rating = 4,
};

// Any property, by namespace URI and local name; structures and arrays nest.
XmpStruct contact = new();
contact.Set(new XmpName(XmpNamespaces.IptcCore, "CiEmailWork"), "photo@example.com");
xmp.Set(new XmpName(XmpNamespaces.IptcCore, "CreatorContactInfo"), contact);
if (xmp.TryGet(new XmpName(XmpNamespaces.DublinCore, "title"), out object? title) && title is XmpArray languages)
{
    languages.SetLanguage("nb-NO", "Havn ved daggry");
}

ReadOnlyMemory<byte> packet = xmp.ToBytes();   // canonical RDF/XML with padding

Constructors

XmpData()

Creates an empty packet, to fill with the setters.

public XmpData()

Properties

City

Gets or sets the city shown (photoshop:City). Setting null removes it.

public string? City { get; set; }

Property Value

string

Country

Gets or sets the country shown (photoshop:Country). Setting null removes it.

public string? Country { get; set; }

Property Value

string

CreateDate

Gets or sets when the content was created (xmp:CreateDate). Setting null removes it.

public DateTimeOffset? CreateDate { get; set; }

Property Value

DateTimeOffset?

CreatorTool

Gets or sets the software that made the file (xmp:CreatorTool). Setting null removes it.

public string? CreatorTool { get; set; }

Property Value

string

Creators

Gets or sets the creators (dc:creator), in order. Setting an empty list removes them.

public IReadOnlyList<string> Creators { get; set; }

Property Value

IReadOnlyList<string>

Credit

Gets or sets the provider credited (photoshop:Credit). Setting null removes it.

public string? Credit { get; set; }

Property Value

string

Description

Gets or sets the description or caption (dc:description), the x-default item. Setting null removes it.

public string? Description { get; set; }

Property Value

string

Headline

Gets or sets the headline (photoshop:Headline). Setting null removes it.

public string? Headline { get; set; }

Property Value

string

IsDamaged

Gets whether the packet could not be read: XML that is not well-formed, no rdf:RDF, or more data than allowed. It then has no properties, and its original bytes are written back unless properties are set.

public bool IsDamaged { get; }

Property Value

bool

Keywords

Gets or sets the keywords (dc:subject). Setting an empty list removes them.

public IReadOnlyList<string> Keywords { get; set; }

Property Value

IReadOnlyList<string>

Label

Gets or sets the color label (xmp:Label), such as "Red". Setting null removes it.

public string? Label { get; set; }

Property Value

string

ModifyDate

Gets or sets when the file was last changed (xmp:ModifyDate). Setting null removes it.

public DateTimeOffset? ModifyDate { get; set; }

Property Value

DateTimeOffset?

Orientation

Gets or sets the orientation (tiff:Orientation), the XMP copy of EXIF's; null when absent or not 1 to 8. Setting null removes it.

public ImageOrientation? Orientation { get; set; }

Property Value

ImageOrientation?

Rating

Gets or sets the rating (xmp:Rating): -1 for rejected, 0 for unrated, 1 to 5 stars. Setting null removes it.

public int? Rating { get; set; }

Property Value

int?

Exceptions

ArgumentOutOfRangeException

The value set is not -1 to 5.

Rights

Gets or sets the rights statement (dc:rights), the x-default item. Setting null removes it.

public string? Rights { get; set; }

Property Value

string

Source

Gets or sets the original owner (photoshop:Source). Setting null removes it.

public string? Source { get; set; }

Property Value

string

Title

Gets or sets the title (dc:title), the x-default item of its language alternatives. Setting null removes it.

public string? Title { get; set; }

Property Value

string

Warnings

Gets what was wrong with the packet when read, as sentences.

public IReadOnlyList<string> Warnings { get; }

Property Value

IReadOnlyList<string>

Methods

Copy()

Returns an independent copy.

public XmpData Copy()

Returns

XmpData

The copy.

Parse(ReadOnlySpan<byte>, SafetyLimits?)

Reads an XMP packet (RDF/XML, with or without its xpacket wrapper). Never throws: a packet that is not well-formed or is over MaxMetadataBytes is marked damaged and keeps its bytes. DTDs are refused and nothing is resolved, so external entities and entity expansion cannot run.

public static XmpData Parse(ReadOnlySpan<byte> packet, SafetyLimits? limits = null)

Parameters

packet ReadOnlySpan<byte>

The packet's bytes, UTF-8 or UTF-16.

limits SafetyLimits

The limits whose MaxMetadataBytes caps the packet. Defaults to Default.

Returns

XmpData

The parsed packet; IsDamaged says whether it was readable.

Examples

// An XMP packet from a sidecar file or a database; DTDs are refused and nothing outside it is read.
XmpData xmp = XmpData.Parse(packet.Span, SafetyLimits.Default with { MaxMetadataBytes = 1024 * 1024 });
Console.WriteLine(xmp.IsDamaged ? string.Join(" ", xmp.Warnings) : $"Label: {xmp.Label}");

ToBytes()

Returns the packet: the original bytes when unedited, otherwise written as canonical RDF/XML with padding.

public ReadOnlyMemory<byte> ToBytes()

Returns

ReadOnlyMemory<byte>

The bytes.

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