Struct DownloadBlobParams 

pub struct DownloadBlobParams<'a> {
    pub download_url_template: &'a JmapUrlTemplate,
    pub account_id: &'a str,
    pub blob_id: &'a str,
    pub name: &'a str,
    pub accept_type: Option<&'a str>,
    pub expected_sha256: Option<&'a Sha256>,
}

Parameters for JmapClient::download_blob.

Use a struct literal to avoid confusion between the string-typed fields:

client.download_blob(DownloadBlobParams {
    download_url_template: &session.download_url,
    account_id: "A13824",
    blob_id: "Gbc4c...",
    name: "attachment.pdf",
    accept_type: Some("application/pdf"),
    expected_sha256: None,
}).await?;

To request integrity verification, construct a typed jmap_cid_types::Sha256 and pass a borrow:

let expected = jmap_cid_types::Sha256::from_hex(
    "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad",
)?;
client.download_blob(DownloadBlobParams {
    // ... other fields ...
    expected_sha256: Some(&expected),
}).await?;

Fields

download_url_template: &'a JmapUrlTemplate

URL template from Session.download_url.

Typed as &JmapUrlTemplate (bd:JMAP-6r7c.40) so the compiler refuses an accidental &session.api_url (a plain JmapUrl).

account_id: &'a str

Account ID that owns the blob.

blob_id: &'a str

Server-assigned blob identifier.

name: &'a str

Human-readable filename for the {name} template variable.

accept_type: Option<&'a str>

Optional accept type for the {type} template variable (e.g. "image/png"). Pass None when no content-type preference is needed; {type} expands to an empty string.

expected_sha256: Option<&'a Sha256>

Optional expected SHA-256 digest for integrity verification. Pass None to skip the check.

The typed jmap_cid_types::Sha256 wrapper guarantees the value is exactly 64 characters of lowercase hex per draft-atwood-jmap-cid-00 §2 ABNF. Construction is the only validation point: callers build the Sha256 via from_hex or deserialize and propagate the Sha256DigestError; download_blob itself does not re-validate, so the &str-validation branch and its ClientError::InvalidArgument mapping no longer exist (bd:JMAP-6r7c.48, bd:JMAP-6r7c.53).

Trait Implementations

impl<'a> Clone for DownloadBlobParams<'a>

fn clone(&self) -> DownloadBlobParams<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Copy for DownloadBlobParams<'a>

impl<'a> Debug for DownloadBlobParams<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.