Export Decorator

The export decorator in dessia_common allows you to define custom export methods for your classes, enabling them to be exported in various formats.

Available Export Decorators

@export_html - Export as HTML (text format)
@export_json - Export as JSON (text format)
@export_step - Export as STEP (text format)
@export_stl - Export as STL (binary format)
@export_docx - Export as DOCX (text format)
@export_xlsx - Export as XLSX (binary format)

Basic Usage

Stream Export (Required)

from dessia_common.decorators import export_html, export_json
from dessia_common.core import DessiaObject
 
class MyClass(DessiaObject):
    @export_html("HTML Export")
    def to_html_stream(self, stream):
        """Export object as HTML to a stream."""
        stream.write("<html><body>Hello World</body></html>")
 
    @export_json("JSON Export")
    def to_json_stream(self, stream):
        """Export object as JSON to a stream."""
        stream.write('{"message": "Hello World"}')

File Export (Optional)

You can also add a file-based export method using the .file decorator:

class MyClass(DessiaObject):
    @export_html("HTML Export")
    def to_html_stream(self, stream):
        """Export object as HTML to a stream."""
        stream.write("<html><body>Hello World</body></html>")
 
    @to_html_stream.file
    def to_html_file(self, filepath):
        """Export object as HTML to a file."""
        with open(filepath, "w") as f:
            self.to_html_stream(f)

Key Points

Selector: Each export decorator requires a unique selector string (e.g., "HTML Export")
Stream Method: The decorated method must accept a stream parameter for writing data
File Method: Optional file-based export using @method_name.file decorator
Text vs Binary: Some formats are text-based (HTML, JSON, STEP) while others are binary (STL, XLSX)
Inheritance: Classes inheriting from DessiaObject or Model get automatic access to export functionality

Example

from dessia_common.decorators import export_json
from dessia_common.core import DessiaObject
 
class Product(DessiaObject):
    def __init__(self, name: str, price: float):
        super().__init__(name=name)
        self.price = price
 
    @export_json("Product Data")
    def export_product_data(self, stream):
        """Export product as JSON."""
        import json
        data = {"name": self.name, "price": self.price}
        stream.write(json.dumps(data, indent=2))

This enables the Product class to be exported as JSON format with the selector "Product Data".

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