# OVAPortableText - Implementation Step 3

## What is added in this step / 本步新增内容

This step upgrades the package from a text-only body builder into a richer report builder that can already express:
本步把包从“仅文本正文构造器”升级为一个更完整的报告构造器，已经能表达：

1. block objects in body content flow / 正文内容流中的块级对象
   - `image`
   - `chart`
   - `table`
   - `math_block`
   - `callout`

2. first typed top-level registries / 第一批强类型顶层 registry
   - `assets.images`
   - `datasets.tables`
   - `datasets.charts` (`pie` only for now)
   - `bibliography`
   - `footnotes`
   - `glossary`

3. more natural append-style APIs / 更自然的 append 风格 API
   - `report.add_image_asset(...)`
   - `report.add_table_dataset(...)`
   - `report.add_chart_dataset(...)`
   - `section.append_image(...)`
   - `section.append_table(...)`
   - `section.append_chart(...)`
   - `section.append_math(...)`
   - `section.append_figure_caption(...)`
   - `section.append_table_caption(...)`
   - `section.append_equation_caption(...)`

4. compatibility helper for your preferred pie-chart input style / 兼容你偏好的饼图输入方式
   - `pie_chart_from_parallel_arrays(...)`

## Main design decisions / 本步主要设计决策

### 1. `content.blocks[]` now supports both text and object blocks
### 1. `content.blocks[]` 现在同时支持文本块和对象块

This follows the protocol decision that body reading order should be a mixed flow.
这符合协议里“正文阅读顺序应为混合流”的设计。

### 2. Registry entries are typed where the protocol is already stable
### 2. 对协议已稳定的 registry 条目做强类型建模

Strong typing is added first for the structures that are already well-defined:
优先对已经定义较稳定的结构做强类型：
- image assets
- table datasets
- pie chart datasets

### 3. Pie chart internal canonical shape is object-array `slices[]`
### 3. 饼图内部正式结构采用对象数组 `slices[]`

But the package also provides a helper to accept your older parallel-array input.
但包同时提供 helper，兼容你以前常用的并行数组输入。

## Files added or changed / 新增或修改的主要文件

- `src/ova_portable_text/text.py`
- `src/ova_portable_text/block_objects.py`
- `src/ova_portable_text/registry.py`
- `src/ova_portable_text/content.py`
- `src/ova_portable_text/document.py`
- `src/ova_portable_text/section.py`
- `src/ova_portable_text/helpers.py`
- `src/ova_portable_text/__init__.py`
- `examples/registry_blocks_report.py`
- `tests/test_blocks_and_registry.py`
- `tests/test_table_dataset_validation.py`
- `tests/test_pie_chart_parallel_arrays.py`

## Suggested next step / 建议下一步

Step 4 should focus on validation and reference resolution:
第 4 步建议聚焦在校验器与引用解析器：

1. global ID indexing / 全局 ID 索引
2. `xref` target resolution / `xref` 目标解析
3. `citation_ref / footnote_ref / glossary_term` resolution / 引文与术语引用解析
4. cross-checking body blocks against registry entries / 正文对象与 registry 条目交叉校验
5. duplicate ID detection / 重复 ID 检测
