HTML parsing and structured outputs

Parsing turns an input representation into a structure you can work with. An HTML document, a JSON message, and a CSV export require different handling. Decide which fields you need and how you will represent missing values before building the extraction step.

Separate extraction from interpretation

First obtain the authorized source and inspect its structure. Next select the relevant values. Then normalize formats and validate the output against an explicit contract. Keeping these stages separate makes it easier to locate a failure when a page layout changes or an input contains unexpected characters.

A practical sequence

• Define field names, required values, and accepted types.
• Parse the source using a parser appropriate to its format.
• Normalize whitespace, dates, and units according to explicit rules.
• Keep validation failures and source context alongside accepted records.

Watch for this failure mode

Missing content is not automatically an empty value. A field may have moved, require a different page state, or be unavailable. Distinguish those cases so downstream systems do not treat extraction errors as genuine business data.

Make the handoff clear

Design a small fixture set with normal, empty, and malformed inputs. Keep examples that previously broke the parser. When the schema changes, document whether the change adds information, renames a field, or alters the meaning of an existing value.

Before expanding the workflow, write one representative success case and one useful failure case. Agree on the result shape and how a reviewer should decide whether the next step can proceed. Keep the example small enough that the assumptions remain visible.

Go deeper

Read the complete parsing guide for examples and design decisions. Connect this step to exports, or return to the workflow library to map the whole sequence.