## What's new

Docling v2 introduces several new features:
- Understands and converts PDF, MS Word, MS Powerpoint, HTML and several image formats 
- Produces a new, universal document representation which can encapsulate document hierarchy
- Comes with a fresh new API and CLI

## Migration from v1

### Setting up a `DocumentConverter`

To accomodate many input formats, we changed the way you need to set up your `DocumentConverter` object.
You can now define a list of allowed formats on the `DocumentConverter` initialization, and specify custom options 
per-format if desired. By default, all supported formats are allowed. If you don't provide `format_options`, defaults 
will be used for all `allowed_formats`.

Format options can include the pipeline class to use, the options to provide to the pipeline, and the document backend.
They are provided as format-specific types, such as `PdfFormatOption` or `WordFormatOption`, as seen below.

```python
from docling.document_converter import DocumentConverter
from docling.datamodel.base_models import InputFormat
from docling.document_converter import (
    DocumentConverter,
    PdfFormatOption,
    WordFormatOption,
)
from docling.pipeline.simple_pipeline import SimplePipeline
from docling.pipeline.standard_pdf_pipeline import StandardPdfPipeline
from docling.backend.pypdfium2_backend import PyPdfiumDocumentBackend

## Default initialization still works as before:
# doc_converter = DocumentConverter() 

## Custom options are now defined per format. 
doc_converter = (
    DocumentConverter(  # all of the below is optional, has internal defaults.
        allowed_formats=[
            InputFormat.PDF,
            InputFormat.IMAGE,
            InputFormat.DOCX,
            InputFormat.HTML,
            InputFormat.PPTX,
        ],  # whitelist formats, non-matching files are ignored.
        format_options={
            InputFormat.PDF: PdfFormatOption(
                pipeline_cls=StandardPdfPipeline, backend=PyPdfiumDocumentBackend
            ),
            InputFormat.DOCX: WordFormatOption(
                pipeline_cls=SimplePipeline  # , backend=MsWordDocumentBackend
            ),
        },
    )
)
```

Note: If you work only with defaults, all remains the same as in Docling v1.

### Converting documents

We have simplified the way you can feed input to the `DocumentConverter` and renamed the conversion methods for 
better semantics. You can now call the conversion directly with a single file, or a list of input files, 
or `DocumentStream` objects, without constructing a `DocumentConversionInput` object first.

* `DocumentConverter.convert` now converts a single file input (previously `DocumentConverter.convert_single`).
* `DocumentConverter.convert_all` now converts many files at once (previously `DocumentConverter.convert`).


```python
...
## Convert a single file (from URL or local path)
conv_result = doc_converter.convert("https://arxiv.org/pdf/2408.09869") # previously `convert_single`

## Convert several files at once:

input_files = [
    "tests/data/wiki_duck.html",
    "tests/data/word_sample.docx",
    "tests/data/lorem_ipsum.docx",
    "tests/data/powerpoint_sample.pptx",
    "tests/data/2305.03393v1-pg9-img.png",
    "tests/data/2206.01062.pdf",
]

conv_results_iter = doc_converter.convert_all(input_files) # previously `convert_batch`

```
Through the `raises_on_error` argument, you can also control if the conversion should raise exceptions when first 
encountering a problem, or resiliently convert all files first and reflect errors in each file's conversion status.
By default, any error is immediately raised and the conversion aborts (previously, exceptions were swallowed).

```python
...
conv_results_iter = doc_converter.convert_all(input_files, raises_on_error=False) # previously `convert_batch`

```

### Exporting documents into JSON, Markdown, Doctags

We have simplified how you can access and export the converted document data, too.

TBD.


### CLI

TBD.