Update v2 documentation

docs/v2.md

@@ -5,7 +5,33 @@ Docling v2 introduces several new features:
 - Produces a new, universal document representation which can encapsulate document hierarchy
 - Comes with a fresh new API and CLI
 
-## Migration from v1
+## Changes in Docling v2
+
+### CLI
+
+We updated the command line syntax of Docling v2 to support many formats. Examples are seen below.
+```shell
+# Convert a single file to Markdown (default)
+docling myfile.pdf
+
+# Convert a single file to Markdown and JSON, without OCR
+docling myfile.pdf --to json --to md --no-ocr
+
+# Convert PDF files in input directory to Markdown (default)
+docling ./input/dir --from pdf
+
+# Convert PDF and Word files in input directory to Markdown and JSON
+docling ./input/dir --from pdf --from docx --to md --to json --output ./scratch  
+
+# Convert all supported files in input directory to Markdown, but abort on first error
+docling ./input/dir --output ./scratch --abort-on-error
+
+```
+
+**Notable changes from Docling v1:**
+- The standalone switches for different export formats are removed, and replaced with `--from` and `--to` arguments, to define input and output formats respectively.
+- The new `--abort-on-error` will abort any batch conversion as soon an error is encountered
+- The `--backend` option for PDFs was removed
 
 ### Setting up a `DocumentConverter`
 
@@ -81,8 +107,9 @@ or `DocumentStream` objects, without constructing a `DocumentConversionInput` ob
 
 ```python
 ...
+from docling.datamodel.document import ConversionResult
 ## Convert a single file (from URL or local path)
-conv_result = doc_converter.convert("https://arxiv.org/pdf/2408.09869") # previously `convert_single`
+conv_result: ConversionResult = doc_converter.convert("https://arxiv.org/pdf/2408.09869") # previously `convert_single`
 
 ## Convert several files at once:
 
@@ -116,7 +143,7 @@ is now available in conversion results as a `DoclingDocument` object.
 `DoclingDocument` provides a neat set of APIs to construct, iterate and export content in the document, as shown below.
 
 ```python
-conv_result = doc_converter.convert("https://arxiv.org/pdf/2408.09869") # previously `convert_single`
+conv_result: ConversionResult = doc_converter.convert("https://arxiv.org/pdf/2408.09869") # previously `convert_single`
 
 ## Inspect the converted document:
 conv_result.document.print_element_tree()
@@ -132,6 +159,11 @@ for item, level in conv_result.document.iterate_items:
         #...
 ```
 
+**Note**: While it is deprecated, you can _still_ work with the Docling v1 document representation, it is available as:
+```shell
+conv_result.legacy_document # provides the representation in previous ExportedCCSDocument type
+```
+
 ## Export into JSON, Markdown, Doctags
 **Note**: All `render_...` methods in `ConversionResult` have been removed in Docling v2,
 and are now available on `DoclingDocument` as:
@@ -140,7 +172,7 @@ and are now available on `DoclingDocument` as:
 - `DoclingDocument.export_to_document_tokens`
 
 ```python
-conv_result = doc_converter.convert("https://arxiv.org/pdf/2408.09869") # previously `convert_single`
+conv_result: ConversionResult = doc_converter.convert("https://arxiv.org/pdf/2408.09869") # previously `convert_single`
 
 ## Export to desired format:
 print(json.dumps(conv_res.document.export_to_dict()))
@@ -148,28 +180,30 @@ print(conv_res.document.export_to_markdown())
 print(conv_res.document.export_to_document_tokens())
 ```
 
-### CLI
-
-We updated the command line syntax of Docling v2 to support many formats. Examples are seen below.
+**Note**: While it is deprecated, you can _still_ export Docling v1 JSON format. This is available through the same 
+methods as on the `DoclingDocument` type:
 ```shell
-# Convert a single file to Markdown (default)
-docling myfile.pdf
+## Export legacy document representation to desired format, for v1 compatibility:
+print(json.dumps(conv_res.legacy_document.export_to_dict()))
+print(conv_res.legacy_document.export_to_markdown())
+print(conv_res.legacy_document.export_to_document_tokens())
+```
 
-# Convert a single file to Markdown and JSON, without OCR
-docling myfile.pdf --to json --to md --no-ocr
+## Reload a `DoclingDocument` stored as JSON
 
-# Convert PDF files in input directory to Markdown (default)
-docling ./input/dir --from pdf
+You can save and reload a `DoclingDocument` to disk in JSON format using the following codes:
 
-# Convert PDF and Word files in input directory to Markdown and JSON
-docling ./input/dir --from pdf --from docx --to md --to json --output ./scratch  
+```python
+# Save to disk:
+doc: DoclingDocument = conv_res.document # produced from conversion result...
 
-# Convert all supported files in input directory to Markdown, but abort on first error
-docling ./input/dir --output ./scratch --abort-on-error
+with Path("./doc.json").open("w") as fp:
+    fp.write(json.dumps(doc.export_to_dict())) # use `export_to_dict` to ensure consistency
+
+# Load from disk:
+with Path("./doc.json").open("r") as fp:
+    doc_dict = json.loads(fp.read())
+    doc = DoclingDocument.model_validate(doc_dict) # use standard pydantic API to populate doc
 
 ```
 
-Notable changes from v1:
-- The standalone switches for different export formats are removed, and replaced with `--from` and `--to` arguments, to define input and output formats respectively.
-- The new `--abort-on-error` will abort any batch conversion as soon an error is encountered
-- The `--backend` option for PDFs was removed

tests/test_e2e_conversion.py

@@ -1,5 +1,8 @@
 from pathlib import Path
 
+import yaml
+from docling_core.types.doc import DoclingDocument
+
 from docling.backend.docling_parse_backend import DoclingParseDocumentBackend
 from docling.datamodel.base_models import InputFormat
 from docling.datamodel.document import ConversionResult
@@ -8,8 +11,8 @@ from docling.document_converter import DocumentConverter, PdfFormatOption
 
 from .verify_utils import verify_conversion_result_v1, verify_conversion_result_v2
 
-GENERATE_V1 = True
-GENERATE_V2 = True
+GENERATE_V1 = False
+GENERATE_V2 = False
 
 
 def get_pdf_paths():