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Lookup Fields

Create dropdown fields that fetch options from another MongoDB collection. Enable cascading lookups for dependent selections.

Configuration​

When configuring a lookup field, you need to specify:

  • Collection - The source collection to fetch options from
  • Display Field - Which field to show in the dropdown (e.g., "name")
  • Value Field - Which field to store as the value (e.g., "_id")
  • Searchable - Enable autocomplete search
  • Multiple - Allow selecting multiple values

Basic Lookup Example​

To create a lookup that references a customers collection:

  1. Add a Lookup field type to your form
  2. Set Collection to customers
  3. Set Display Field to name
  4. Set Value Field to _id
  5. Enable Searchable if the collection is large

The dropdown will show customer names, but store the customer _id in your document.

Cascading Lookups​

Create dependent dropdowns where the options in one field are filtered based on another field's selection.

Example: Country → State​

First, select a Country, then the State dropdown shows only states from that country.

Configuration Steps:

  1. Create a Country lookup field

    • Collection: countries
    • Display Field: name
    • Value Field: _id

  2. Create a State lookup field

    • Collection: states
    • Display Field: name
    • Value Field: _id
    • Filter Field: countryId
    • Filter Source: Point to the Country field

When a country is selected, the State lookup automatically filters to show only states where countryId matches the selected country.

Filter Options​

Static Filters​

Filter lookup options with a static query:

{
  "status": "active",
  "type": "customer"
}

Dynamic Filters​

Filter based on other form field values:

  • Reference current form values
  • Update options when dependencies change
  • Chain multiple cascading lookups

Advanced Options​

Searchable Lookups​

Enable search for large collections:

  • Users can type to filter options
  • Server-side search for performance
  • Debounced search requests

Multiple Selection​

Allow selecting multiple values:

  • Stores as array in MongoDB
  • Tag-style display
  • Min/max selection limits

Custom Display​

Customize how options appear:

  • Combine multiple fields for display
  • Format values (currency, dates)
  • Add icons or badges
tip

For large collections, enable "Searchable" to let users type and filter options instead of loading all values upfront.

Use Cases​

  • Customer Selection - Pick from existing customers
  • Category Assignment - Assign categories from a list
  • User Assignment - Assign tasks to team members
  • Product Selection - Select products for an order
  • Location Hierarchy - Country → State → City

Best Practices​

  1. Index lookup fields - Ensure MongoDB indexes on queried fields
  2. Limit results - Don't load thousands of options at once
  3. Enable search - For collections with many documents
  4. Use meaningful displays - Show names, not IDs
  5. Consider performance - Use pagination for large datasets

Next Steps​