Enum theory::MetadataEntry

#[non_exhaustive]
pub enum MetadataEntry {
    Title(String),
    Author(String),
    Language(String),
    Date(u64),
    License(String),
    Keyword(String),
    User(String, String),
}

Metadata associated to a book or a page.

Adding Metadata Entries

Entries can be added with the add_metadata function of each type.

use theory::{Book, MetadataEntry::{Keyword, Title}};

let mut builder = Book::builder();
builder.add_metadata(Title("The Book".into()));

builder
    .new_page("Introduction")
    .add_metadata(Keyword("intro".into()));

Reading Metadata Entries

Both Book and Page provide a metadata function to get all entries associated with the item.

For example, to get the title of a book:

use std::io::{Read, Seek};
use theory::{Book, MetadataEntry::Title, errors::MetadataError};

fn book_title<T>(book: &mut Book<T>) -> Result<Option<String>, MetadataError>
where
    T: Read + Seek,
{
    for entry in book.metadata()? {
        if let Title(t) = entry? {
            return Ok(Some(t));
        }
    }

    Ok(None)
}

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Title(String)

Author(String)

Language(String)

Date(u64)

License(String)

Keyword(String)

User(String, String)

Trait Implementations

impl Clone for MetadataEntry

fn clone(&self) -> MetadataEntry

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MetadataEntry

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

Formats the value using the given formatter.

impl PartialEq<MetadataEntry> for MetadataEntry

fn eq(&self, other: &MetadataEntry) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for MetadataEntry

impl StructuralEq for MetadataEntry

impl StructuralPartialEq for MetadataEntry