CSV response format for graphql read API

[rufuspollock]

When I have selected the data I want in the Build Report I want to be able to download in CSV format so that I can use it easily in my tools e.g. a spreadsheet, database etc

Acceptance

• [x] I can make a query to build report API and indicate that I want results returned in CSV
• [x] The results are returned in CSV

Tasks

• [x] Design the API structure
• [x] Add format query string to "graphql" endpoint with default to JSON
• [x] Stream response instead of simple response.
• [x] Implement CSV format option with conversion to CSV from JSON response
  • [x] Implement different separation formats TSV, |, ;,
  • [x] Tests

Analysis

Current

/.../graphql

POST request

{  query MyQuery {
    build_report_capacityauction {
      MonthlyAuctionConRentDKK_DK1
      UtilizedExportCapacity_DK1
    }
  }
}

New

POST with existing type of body to:

.../graphql?format=json|csv|xlsx

Options

New format:

Option 1:

POST /.../

Nicest:

.../graphql?format=json|csv|xlsx

Option 2:

{
  "format": "json | csv | xlsx",
  "graphql": "query MyQuery {
    build_report_capacityauction {
      MonthlyAuctionConRentDKK_DK1
      UtilizedExportCapacity_DK1
    }
  }"
}

[leomrocha]

All formats supported by (js-xlsx)[https://github.com/SheetJS/sheetjs] will be easy to support with data-api after the current branch is tested and merged to the master. For accepted formats read Library Documentation

[rufuspollock]

@leomrocha 👏 👏

Can we add a comment when closing as per https://playbook.datopian.com/issues-tasks/#closing-issues

[leomrocha]

Functionality implemented and tested in the Merged code feature/downloads PR #20