Data Entry

GHG Emissions Calculator

When visiting the page at URL “/app/{profile}/track/energy-ghg-emissions/” (djaopsp.views.assess.TrackMetricsView), the server will populate the template “djaopsp/templates/app/track/energy-ghg-emissions.html” with a context that includes API endpoints dynamically generated by get_editable_filter_context(self, context, candidate_paths, title=None).

The first path in candidate_paths matching a Question and the slugified title are used to retrieve or create an EditableFilter for the profile with extra ~= {"path": path, "tags": [slugify(title)]}.

The name of the dynamic endpoint is created out of the slugify(title) or the last part of the path such that it is associated properly in the template. The value of the endpoint is reverse('survey_api_accounts_filter', args=(self.account, editable_filter.slug,).

In the browser, the Vue components scope1-stationary-combustion, scope1-mobile-combustion, scope1-refrigerants, scope2-purchased-electricity, scope3-transportation (all defined in “assess.js”; extending ghg-emissions-estimator, itself extending data-metric-tracker) will call their respective dynamic API endpoint “/api/{profile}/filters/accounts/{editable_filter}” ( survey.api.matrix.AccountsFilterDetailAPIView) to load the list of facilities/profiles in that category (scope1-stationary-combustion, scope1-mobile-combustion, etc.) to enter data for.

CRUD on list in a category

Adding, updating and deleting a row is done through the Adds a profile to a group, Updates a selector in a group, and Removes a selector from a group respectively.

When creating a new row in the calculator, both the facility and fuel type are required. The profile.full_name is set as the facility name, and the fuel type is saved in the extra field (ex: {"fuel_type":"natural-gas"}).

Recording energy use and GHG Emissions calculated

When a user clicks on the “Record” button, the Vue component will use the parent ‘ghg-emissions-estimator’ save method to calculated GHG Emissions and persist both the energy use and GHG Emissions calculated through the Records quantitative measurements API.

For example:

POST /api/supplier-1/filters/accounts/scope1-stationary-combustion/values HTTP/1.1

{
    "baseline_at":"2025-01-01",
    "created_at":"2025-12-31",
    "items":[{
        "slug": "office",
        "measured": 10,
        "unit": "btu"
    }, {
        "slug": "office",
        "measured": 0.0000010756,
        "unit": "t"
    }]
}

“Encoding answers in the database” in the djaodjin-survey documentation has details on how the quantitative values are stored in the database.

Using the calculator results

On the GHG Emissions calculated have been recorded in the database, it is possible to aggregate them to answer questions that require to a total GHG Emissions. The “Use calculator result” button in a questionnaire assess step does just that.

For example:

GET /api/supplier-1/metrics/aggregate/sustainability/environmental-reporting/ghg-emissions-reporting/ghg-emissions-scope1-measured/ghg-emissions-scope1?start_at=2025-01-01&ends_at=2025-12-31&unit=t HTTP/1.1

{
  "measured": 0.0000010756,
  "unit":"t"
}

“Aggregates” in the djaodjin-survey documentation has details on how aggregates of quantitative values are retrieved from the database.