Trawley
Building scrapers

Choosing fields

Pick the right fields and data types so your results are clean and searchable.

Fields are the pieces of data Trawley captures from each item. Choosing them well makes your results easier to read, search, and filter.

What makes a good field

  • One value per field. Keep price and bedrooms separate rather than a single "details" blob. Separate fields are searchable on their own.
  • Capture a stable identifier. A link or title that uniquely identifies each item lets Trawley track changes between runs and power diffs.
  • Only what you need. Every field is something to maintain. Skip data you will not use.

Data types

Each field has a type. The type controls how the value is stored and, crucially, how you can search it later.

TypeUse forLets you
TextTitles, descriptions, locationsSearch by meaning and keywords
NumberPrices, counts, sizesFilter by ranges (under £500k, 3+ beds)
DateListed dates, deadlinesFilter and sort by time
BooleanYes/no flags (has parking)Filter to true or false

Getting number and date types right matters most. Trawley uses them to build exact filters during search, so "under £500k" only works if price is a number, not text. The wizard suggests types for you, but it is worth a quick check.

Letting the wizard help

You do not assign types by hand from a blank slate. As you describe your fields in the setup wizard, it proposes a sensible type for each one based on the real values on the page. You confirm or correct.

What's next