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https://github.com/Serial-ATA/lofty-rs
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41 lines
1.3 KiB
Text
41 lines
1.3 KiB
Text
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# Downcast
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The following example shows how you can downcast a `Box<dyn AudioTag>` into its "backend" tag type. This allows you to set the uncommon metadata supported by the corresponding backend but not by **audiotags**.
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```rust
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use audiotags::*;
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fn main() {
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let mut innertag = metaflac::Tag::default();
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innertag
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.vorbis_comments_mut()
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.set_title(vec!["title from metaflac::Tag"]);
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let tag: FlacTag = innertag.into();
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let mut id3tag = tag.into_tag(TagType::Id3v2);
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id3tag
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.write_to_path("assets/a.mp3")
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.expect("Fail to write!");
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let id3tag_reload = Tag::default()
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.read_from_path("assets/a.mp3")
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.expect("Fail to read!");
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assert_eq!(id3tag_reload.title(), Some("title from metaflac::Tag"));
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let mut id3tag_inner: id3::Tag = downcast!(id3tag_reload, Id3v2Tag);
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let timestamp = id3::Timestamp {
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year: 2013,
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month: Some(2u8),
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day: Some(5u8),
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hour: Some(6u8),
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minute: None,
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second: None,
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};
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id3tag_inner.set_date_recorded(timestamp.clone());
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id3tag_inner
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.write_to_path("assets/a.mp3", id3::Version::Id3v24)
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.expect("Fail to write!");
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let id3tag_reload = id3::Tag::read_from_path("assets/a.mp3").expect("Fail to read!");
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assert_eq!(id3tag_reload.date_recorded(), Some(timestamp));
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}
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```
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