Struct e57::Extension

pub struct Extension {
    pub namespace: String,
    pub url: String,
}

Describes an E57 extension by name and URL.

The E57 specification includes an mechanism for extensions. Each extension has its own namespace in the XML section of the E57 file. Such extensions can for example specify custom point attributes or add additional metadata and custom binary blobs.

Every E57 parser must be able to ignore any unknown extensions. Some extensions are officially documented, others are proprietary and have no public documentation.

Since full extension support involves all kinds of XML operations, it can greatly increase the API of any E57 library. This library is using a more pragmatic approach and requires you to bring your own XML library. This allows the API of this library to stay small, focused and lightweight.

Extension features directly supported by this library are:

• reading and defining of XML namespaces for extensions
• reading and writing additional custom point attributes
• reading and writing of binary blobs

Extensions that require specific XML parsing are possible. You need to load your E57 file and then call E57Reader::xml() method to get the full original XML string. This will return an UTF8 string that can be feed into an XML parser. This library is using roxmltree for lightweight XML parsing.

Extensions that require XML manipulation when writing E57 files are also possible. You need to first finishing writing all point clouds, images and binary blobs. Then when you are ready to call E57Writer::finalize() to write the XML section and close the file, you need to call E57Writer::finalize_customized_xml() instead. This allows you to supply a transformer that will receive the generated XML string and can manipulate it before its written into the file. Your code is responsible for parsing, modifying and serializing th XML again in a non-destructive way!

Example Code

You can find a complete example for reading and writing E57 files with extensions in the automated tests of the library.

Fields

namespace: String

XML namespace name.

url: String

XML namespace URL.

Implementations

impl Extension

pub fn new(namespace: &str, url: &str) -> Self

Intialize and return a new Extension structure with the given values.

Trait Implementations

impl Clone for Extension

fn clone(&self) -> Extension

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Extension

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

Formats the value using the given formatter.