Struct shapefile::reader::Reader

pub struct Reader<T: Read> { /* fields omitted */ }

struct that reads the content of a shapefile

Methods

impl<T: Read> Reader<T>

pub fn new(source: T) -> Result<Reader<T>, Error>

Creates a new Reader from a source that implements the Read trait

The Shapefile header is read upon creation (but no reading of the Shapes is done)

Errors

Will forward any std::io::Error

Will also return an error if the data is not a shapefile (Wrong file code)

Will also return an error if the shapetype read from the input source is invalid

Example

use std::fs::File;
let file = File::open("tests/data/line.shp").unwrap();
let reader = shapefile::Reader::new(file).unwrap();

pub fn header(&self) -> &Header

Returns a non-mutable reference to the header read

Examples

let reader = shapefile::Reader::from_path("tests/data/pointz.shp").unwrap();
let header = reader.header();
assert_eq!(header.shape_type, shapefile::ShapeType::PointZ);

pub fn read_as<S: ReadableShape>(self) -> Result<Vec<S>, Error>

Reads all the shape as shape of a certain type.

To be used if you know in advance which shape type the file contains.

Errors

The function has an additional error that is returned if the shape type you asked to be read does not match the actual shape type in the file.

Examples

use shapefile::Reader;
let mut reader = Reader::from_path("tests/data/linem.shp").unwrap();
let polylines_m = reader.read_as::<shapefile::PolylineM>().unwrap(); // we ask for the correct type

use shapefile::Reader;
let mut reader = Reader::from_path("tests/data/linem.shp").unwrap();
let polylines = reader.read_as::<shapefile::Polyline>(); // we ask for the wrong type
assert_eq!(polylines.is_err(), true);

pub fn read(self) -> Result<Vec<Shape>, Error>

Reads all the shapes and returns them

Examples

use shapefile::Reader;
let mut reader = Reader::from_path("tests/data/multipoint.shp").unwrap();
let shapes = reader.read().unwrap();
for shape in shapes {
    match shape {
        shapefile::Shape::Multipoint(pts) => println!(" Yay Multipoints: {}", pts),
        _ => panic!("ups, not multipoints"),
    }
}

pub fn read_records(self) -> Result<Vec<Record>, Error>

Read and return only the records contained in the .dbf file

Important traits for ShapeIterator<T, S>

impl<T: Read, S: ReadableShape> Iterator for ShapeIterator<T, S> type Item = Result<S, Error>;

pub fn iter_shapes_as<S: ReadableShape>(self) -> ShapeIterator<T, S>

Returns an iterator that tries to read the shapes as the specified type Will return an error of the type S does not match the actual type in the file

Examples

let reader = shapefile::Reader::from_path("tests/data/multipoint.shp").unwrap();
for multipoints in reader.iter_shapes_as::<shapefile::Multipoint>() {
    let points = multipoints.unwrap();
    println!("{}", points);
}

Important traits for ShapeIterator<T, S>

impl<T: Read, S: ReadableShape> Iterator for ShapeIterator<T, S> type Item = Result<S, Error>;

pub fn iter_shapes(self) -> ShapeIterator<T, Shape>

Returns an iterator that to reads the shapes wraps them in the enum Shape You do not need to call this method and can iterate over the Reader directly

Examples

let reader = shapefile::Reader::from_path("tests/data/multipoint.shp").unwrap();
for shape in reader.iter_shapes() {
    match shape.unwrap() {
        shapefile::Shape::Multipatch(shp) => println!("Multipoint!"),
        _ => println!("Other type of shape"),
    }
}

let reader = shapefile::Reader::from_path("tests/data/multipoint.shp").unwrap();
for shape in reader {
    match shape.unwrap() {
        shapefile::Shape::Multipatch(shp) => println!("Multipoint!"),
        _ => println!("Other type of shape"),
    }
}

pub fn iter_shapes_and_records_as<S: ReadableShape>(
    self
) -> Result<ShapeRecordIterator<T, S>, Error>

Returns an iterator over the Shapes and their Records

Errors

The Result will be an error if the .dbf wasn't found

Example

use shapefile::{Reader, Multipatch};
let reader = Reader::from_path("tests/data/multipatch.shp").unwrap();
for result in reader.iter_shapes_and_records_as::<Multipatch>().unwrap() {
    let (shape, record) = result.unwrap();
    // ...
}

pub fn iter_shapes_and_records(
    self
) -> Result<ShapeRecordIterator<T, Shape>, Error>

Returns an iterator over the Shapes and their Records

Errors

The Result will be an error if the .dbf wasn't found

Example

use shapefile::{Reader, Shape};
let reader = Reader::from_path("tests/data/multipatch.shp").unwrap();
for result in reader.iter_shapes_and_records().unwrap() {
    let (shape, record) = result.unwrap();
    match shape {
        Shape::Multipatch(multip) => {/*...*/ },
        //..
        _ => { /*...*/ }
    }
    // ...
}

pub fn add_index_source(&mut self, source: T) -> Result<(), Error>

Reads the index file from the source This allows to later read shapes by giving their index without reading the whole file

(see read_nth_shape())

pub fn add_dbf_source(&mut self, source: T) -> Result<(), Error>

Adds the source as the source where the dbf record will be read from

impl Reader<BufReader<File>>

pub fn from_path<P: AsRef<Path>>(path: P) -> Result<Self, Error>

Creates a reader from a path to a file

Will attempt to read both the .shx and .dbf associated with the file, if they do not exists the function will not fail, and you will get an error later if you try to use a function that requires the file to be present.

Examples

use std::path::Path;
assert_eq!(Path::new("tests/data/linem.dbf").exists(), false);
assert_eq!(Path::new("tests/data/linem.shx").exists(), false);

// both .shx and .dbf does not exists, but creation does not fail
let mut reader = shapefile::Reader::from_path("tests/data/linem.shp").unwrap();
let result = reader.iter_shapes_and_records();
assert_eq!(result.is_err(),  true);


assert_eq!(Path::new("tests/data/multipatch.dbf").exists(), true);

let mut reader = shapefile::Reader::from_path("tests/data/multipatch.shp").unwrap();
let result = reader.iter_shapes_and_records();
assert_eq!(result.is_err(),  false);

use shapefile::Reader;
let mut reader = Reader::from_path("tests/data/line.shp").unwrap();
let polylines = reader.read_as::<shapefile::Polyline>().unwrap();

impl<T: Read + Seek> Reader<T>

Sources that implements Seek have access to a few more methods that uses the index file(.shx)

pub fn read_nth_shape_as<S: ReadableShape>(
    &mut self,
    index: usize
) -> Option<Result<S, Error>>

Reads the nth shape of the shapefile

Returns

None if the index is out of range

Errors

This method will return an Error::MissingIndexFile if you use it but no .shx was found when opening the shapefile.

pub fn read_nth_shape(&mut self, index: usize) -> Option<Result<Shape, Error>>

Reads the nth shape of the shapefile

Trait Implementations

impl<T: Read> IntoIterator for Reader<T>

type Item = Result<Shape, Error>

The type of the elements being iterated over.

type IntoIter = ShapeIterator<T, Shape>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.