Document Merge Pattern¶
The Document Merge Pattern is a strategy for combining multiple individual files into a single composite document.^[001-TODO__code_copy.md] This approach is commonly utilized in reporting systems to aggregate related data sets, such as compiling separate data queries into one downloadable file.
Implementation Logic¶
The core of this pattern involves the programmatic concatenation of byte streams, while handling technical constraints like header duplication.
- Header Removal: When combining structured text files like CSVs, the merge process must strip the header row from subsequent documents to prevent duplicate titles in the middle of the output.^[001-TODO__code_copy.md]
- Data Concatenation: The algorithm retrieves the byte content of each source document and joins them sequentially.^[001-TODO__code_copy.md]
- Error Handling: The process includes validation to ensure data exists before merging; for instance, operations may fail if the source list is empty or if the external storage service returns no data.^[001-TODO__code_copy.md]
Technical Context¶
This pattern typically involves orchestrating between storage services and document converters. It relies on asynchronous event queues—such as a dedicated "combine file" queue—to trigger the merge job, separating the aggregation logic from the main request thread.^[001-TODO__code_copy.md]
Sources¶
001-TODO__code_copy.md