parcels

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parcels Configuration

Parcels are the main interactive elements on the map in a Mapboard app - clicking on them triggers the app to identify which parcels have been clicked on, and geocode the results.

Most cities only have 1 parcel layer. Philadelphia has 2: water (PWD) parcels, and records (DOR) parcels. Eventually you won't have to use both, but right now the datafetching requires both, and requires this part of the config, which includes a lot of specific options for helping Mapboard use the 2 parcel sets well.

Because you can put in multiple parcel sets, each topic can say which parcel set it is using. So depending on which topic is open, a click on the map is prioritizing a certain parcel layer. If the current topic is 'Properties' a map click is a 'pwd parcel' query, and if the current topic is 'deeds', a map click is a 'dor parcel' query.

There is a very opaque set of options for parcels which come from this setup:

option	definition
multipleAllowed	DOR parcels can overlap each other, so clicking on multiple is possible, while it should never happen for PWD parcels
geocodeFailAttemptParcel	Allows you to set whether it should attempt to geocode the other kind of parcel if the geocode of the parcel fails
wipeOutOtherParcelOnReverseGeocodeOnly
geocodeField	The field of the parcel dataset to use for geocoding
parcelIdInGeocoder	The field of the geocoder results that corresponds to the geocodeField
getByLatLngIfIdFails

Example:

parcels: {
  pwd: {
    multipleAllowed: false,
    geocodeFailAttemptParcel: null,
    clearStateOnError: false,
    wipeOutOtherParcelsOnReverseGeocodeOnly: true,
    geocodeField: 'PARCELID',
    parcelIdInGeocoder: 'pwd_parcel_id',
    getByLatLngIfIdFails: false
  },
  dor: {
    multipleAllowed: true,
    geocodeFailAttemptParcel: 'pwd',
    clearStateOnError: true,
    wipeOutOtherParcelsOnReverseGeocodeOnly: false,
    geocodeField: 'MAPREG',
    parcelIdInGeocoder: 'dor_parcel_id',
    getByLatLngIfIdFails: true
  }
},

Further Research

Mapboard's handling of Philadelphia's multiple parcels is complicated:

Download that PowerPoint from here and print on a plotter.