NowAttachmentMetadata structure - iOS

The NowAttachmentMetadata structure provides functions that enable you to encode and manage attachment metadata.

Table 1. Properties

Name	Type	Description
averageImageColor	String	Most dominant color in the associated image.
chunkSizeInBytes	Integer	Size of the chunk. Unit: Bytes
compressed​Size​InBytes	Integer	Compressed size of the attachment. Unit: Bytes
created	Date	Date on which the attachment was created.
createdBy	String	Entity that created the attachment.
download	URL	URL of the attachment on the ServiceNow instance.
fileName	String	Name of the attachment file.
hash	String	Expected SHA256 digest for the attachment. A downloaded attachment is validated by comparing its computed digest to this SHA256 digest.
imageHeight	Integer	Height of image. Unit: Pixels
imageWidth	Integer	Width of image. Unit: Pixels
isCompressed	Boolean	Flag that indicates whether the attachment file is compressed. Possible values: true: Attachment is compressed. false: Attachment in not compressed.
mimeType	String	Attachment MIME type.
modificationCount	Integer	Number of times that the attachment was modified.
sizeInBytes	Integer	Size of the attachment. Unit: Bytes
sourceSysId	String	Sys_id of the attachment file.
sourceTableName	String	Name of the source table in which the attachment resides.
state		Availability state, such as conditionally, unavailable, available, and pending.
sysId	String	Unique 32-character Globally Unique ID (GUID), that identifies each record in a ServiceNow instance.
tags	String	List of tags associated with the attachment.
updated	Date	Date on which the attachment was last modified.
updatedBy	String	Entity that updated the attachment.

NowAttachmentMetadata - encode(to encoder: Encoder)

Encodes the current object value into data using the specified encoder.

If the object fails to be encoded into data, the encoder encodes an empty keyed container in its place. This function also throws an error if any values are invalid for the specified encoder's format.

Table 2. Parameters

Name	Type	Description
to encoder	Encoder	Encoder that defines the structure of the encoded output.

Table 3. Returns

Type	Description
None

The following code example shows how to call this function.

let query = "active=true^short_descriptionLIKEbroken"
let filter = Filter(query: query)
metadataPublisher(filter: filter, limit: 1)
private func metadataPublisher(filter: Filter?, limit: Int?) {
  let publisher = attachmentService.attachmentMetadata(filter: filter, limit: limit)
  publisher
  .receive(on: DispatchQueue.main)
  .encode(encoder: JSONEncoder())
  .sink { [weak self] completion in
    if case let .failure(error) = completion {
      // attachment published failed, return NowDataError
    }
  } receiveValue: { [weak self] (data) in
    // Attachment published successful, return data
  }
  .store(in: &subscriptions)
}

NowAttachmentMetadata - init(from decoder: Decoder)

Creates a new NowAttachmentMetadata instance by decoding data into an object from the specified decoder.

This method throws an error if reading from the decoder fails or if the data read is corrupt or otherwise invalid.

Table 4. Parameters

Name	Type	Description
decoder	Decoder	Decoder to read data from.

Table 5. Returns

Type	Description
None

The following code example shows how to call this function.

guard 
  let metadataHeader = response.httpResponse?.value(forHTTPHeaderField: NowAttachment.attachmentMetadataHeaderKey),
  let metadataHeaderData = metadataHeader.data(using: .utf8) else {
    throw NowDataError.missingAttachmentMetadata
  }
            
let metadata = try coder.decode(NowAttachmentMetadata.self, from: metadataHeaderData)
let attachment = NowAttachment(metadata: metadata, data: response.data)