Struct WriterBuilder

pub struct WriterBuilder(/* private fields */);

JSON writer builder.

Implementations

impl WriterBuilder

pub fn new() -> WriterBuilder

Create a new builder for configuring JSON writing options.

Example

fn example() -> Writer<File, LineDelimited> {
    let file = File::create("target/out.json").unwrap();

    // create a builder that keeps keys with null values
    let builder = WriterBuilder::new().with_explicit_nulls(true);
    let writer = builder.build::<_, LineDelimited>(file);

    writer
}

pub fn explicit_nulls(&self) -> bool

Returns true if this writer is configured to keep keys with null values.

pub fn with_explicit_nulls(self, explicit_nulls: bool) -> WriterBuilder

Set whether to keep keys with null values, or to omit writing them.

For example, with LineDelimited format:

Skip nulls (set to false):

{"foo":1}
{"foo":1,"bar":2}
{}

Keep nulls (set to true):

{"foo":1,"bar":null}
{"foo":1,"bar":2}
{"foo":null,"bar":null}

Default is to skip nulls (set to false). If struct_mode == ListOnly, nulls will be written explicitly regardless of this setting.

pub fn struct_mode(&self) -> StructMode

Returns if this writer is configured to write structs as JSON Objects or Arrays.

pub fn with_struct_mode(self, struct_mode: StructMode) -> WriterBuilder

Set the StructMode for the writer, which determines whether structs are encoded to JSON as objects or lists. For more details refer to the enum documentation. Default is to use ObjectOnly. If this is set to ListOnly, nulls will be written explicitly regardless of the explicit_nulls setting.

pub fn build<W, F>(self, writer: W) -> Writer<W, F>

where W: Write, F: JsonFormat,

Create a new Writer with specified JsonFormat and builder options.

Trait Implementations

impl Clone for WriterBuilder

fn clone(&self) -> WriterBuilder

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for WriterBuilder

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

Formats the value using the given formatter.

impl Default for WriterBuilder

fn default() -> WriterBuilder

Returns the “default value” for a type.