fix: convert gps_location from Python extractor to SQL path extraction

[akkaouim]

The extract_gps_location() extractor forced the SQL query to load form_json for all ~48k visits into Python memory (~480MB), causing the Fargate container to OOM-crash during process_and_cache().

Replace with COALESCE path-based extraction:

• form.meta.location.#text (dict with #text key)
• form.meta.location (string fallback)

This runs entirely in PostgreSQL — zero Python memory for form_json. All 13 pipeline fields are now path-based; no extractors remain.

Summary by CodeRabbit

• Bug Fixes

  • Improved GPS extraction reliability in MBW monitoring so location is consistently read from form data across different formats, removing fragile extractor behavior.

• Documentation

  • Clarified pipeline docs to reflect the new path-based GPS extraction approach and noted memory/processing considerations for large form sets.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 14c2c15 and 5ae3447.

📒 Files selected for processing (1)

• commcare_connect/workflow/templates/mbw_monitoring/DOCUMENTATION.md

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📝 Walkthrough

Walkthrough

Consolidates GPS extraction in the MBW monitoring pipeline by removing the Python extractor and switching gps_location to a path-based FieldComputation that uses two paths with SQL COALESCE fallback to handle both dict and string location formats.

Changes

Cohort / File(s)	Summary
GPS Extraction Refactor commcare_connect/workflow/templates/mbw_monitoring/pipeline_config.py, commcare_connect/workflow/templates/mbw_monitoring/DOCUMENTATION.md	Removed extract_gps_location helper and updated gps_location FieldComputation to use paths=[ "form.meta.location.#text", "form.meta.location" ]. Documentation updated to describe path-based extraction and COALESCE fallback; all 13 Visit form fields now path-extracted (no extractor use).

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• Continued work on mbw v1 using updated pipeline work #25 — Related work converting visit field extraction to path-based FieldComputations and handling extractor support in the SQL backend.

Poem

🐰 Hopping through the pipeline bright,
Paths replace the tweaked old byte,
COALESCE finds the spot to roam,
GPS now finds its home,
Crunching data, carrot-sweet delight. 🥕

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly and accurately reflects the main change: converting gps_location extraction from a Python extractor function to SQL path-based extraction, addressing a critical memory issue.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@commcare_connect/workflow/templates/mbw_monitoring/DOCUMENTATION.md`:
- Line 558: Update the documentation so every occurrence of the gps_location
extractor is documented as a paths-based field (not extractor-based); find all
sections that currently describe gps_location as "extractor-based" and change
them to match the table row showing gps_location → paths with paths
`form.meta.location.#text`, `form.meta.location` and the COALESCE behavior (dict
`#text` key or string fallback); ensure any examples, headings, and migration
notes that mention gps_location/original extractor usage are rewritten to show
the paths-based extractor and consistent wording about COALESCE and path
resolution.

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ℹ️ Review info

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 84d802b and 14c2c15.

📒 Files selected for processing (2)

• commcare_connect/workflow/templates/mbw_monitoring/DOCUMENTATION.md
• commcare_connect/workflow/templates/mbw_monitoring/pipeline_config.py