address locators


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Address Locators

Geocoding can be thought of as a very complex table join. Rather than linking the address table to the streets table using a single field, there are many linking fields that need to be identified and many other aspects of the geocoding results that should be specified. Rather than doing this each time you geocode, ArcSDE lets you set up all of the parameters of this join with an address locator. Thus, the address locator is the cornerstone of the geocoding process in ArcGIS.

An address locator is an object that converts nonspatial descriptions of locations into feature representations of those locations.

Most commonly, address locators are used to convert address strings into point features that represent the locations of those addresses. In other words, an address locator is an entity that specifies the method to interpret a particular type of address input, relate it to the predefined reference data, and deliver a certain type of output back to the user interface. The reference data usually consists of a feature class along with the underlying database table.

Every address locator has a style which is the template on which it is built. Each template is designed to accommodate a specific format of address and reference data. A style can also be called the skeleton of the address locator. The choice of locator styles is based on the entities you will search as well as the type of data you have.

Advanced use of address locators

Some applications might require custom address locator behavior and interactive processing. For instance, instead of relying on automatic address matching, an application may allow the user to manually select the matching address after reviewing several of the match candidates returned by an address locator. This can be accomplished by switching the locator to candidate mode:

rc = SE_locatorinfo_set_single_property(locator, “CandidateMode”, “TRUE”);
check_error(Connection, NULL, rc, "SE_locatorinfo_set_single_property");
/* use the same code as in “Locating a single address” section */

In this case, unlike the automatic mode, the locator will return several records for each input address. Also, the output column set will also be different—it will have columns for all street segment components and street intersection components, as well as columns such as shape, score, match status, and result type (address or intersection).

Generally, the advanced use of locators involves modification of the locator’s properties. For detailed information on customizing address locators, see "Geocoding in ArcGIS" or the ArcGIS Desktop Help.