Field Dependency And Controlling

Field Dependency and Controlling

Activate when configuring dependent picklists — Salesforce's built-in mechanism for filtering a picklist's options based on another field's value. UI honors the matrix; the API does not enforce it the way users expect.

Before Starting

• Check controlling-field type. Only picklist or checkbox. Multi-select picklists cannot be controlling fields.
• Count values. Controlling picklist up to 300 values; dependent up to 300. Each controlling value can have up to 300 dependent values enabled.
• Decide per record type. Picklist dependencies are global for a field, but picklist values can be filtered further per Record Type.

Core Concepts

Controlling vs Dependent

A controlling field determines which values of a dependent picklist are available. The mapping is a matrix stored in the dependent picklist's valueSettings.

<fields>
    <fullName>Category__c</fullName>
    <type>Picklist</type>
    <valueSet>
        <controllingField>Parent_Category__c</controllingField>
        <valueSetDefinition>
            <value><fullName>Laptops</fullName></value>
            <value><fullName>Desktops</fullName></value>
        </valueSetDefinition>
        <valueSettings>
            <controllingFieldValue>Computers</controllingFieldValue>
            <valueName>Laptops</valueName>
        </valueSettings>
        <valueSettings>
            <controllingFieldValue>Computers</controllingFieldValue>
            <valueName>Desktops</valueName>
        </valueSettings>
    </valueSet>
</fields>

UI vs API enforcement

• UI (LEX, Aura, LWC standard components): Enforces the matrix. Users see only valid combinations.
• SOAP/REST API, Apex DML, Data Loader: Does NOT enforce the matrix by default. You can insert Parent=Computers, Category=Phones via API and it succeeds.
• To enforce on API writes: add a Validation Rule or a Before-Save flow/trigger.

Checkbox as controlling field

Checkbox has two "values": true and false. The matrix is a 2-column table.

Global Value Sets

If either field uses a Global Value Set, dependencies are still per-field — the dependency metadata lives on the dependent field, not the GVS.

Record Types add a second filter

RecordType → picklistValues further limits values. Order of filters: Record Type restricts first, then controlling field filters within that subset.

Common Patterns

Pattern: API validation rule for dependent picklist

AND(
  ISPICKVAL(Parent_Category__c, "Computers"),
  NOT(ISPICKVAL(Category__c, "Laptops")),
  NOT(ISPICKVAL(Category__c, "Desktops"))
)

Covers the case where API writes skip UI filtering.

Pattern: LWC dependent combobox

import { getPicklistValues } from 'lightning/uiObjectInfoApi';

@wire(getPicklistValues, {
    recordTypeId: '$recordTypeId',
    fieldApiName: PRODUCT_OBJECT.fieldApiName
})
picklistValues({ data }) {
    if (data) {
        this.controllerMap = data.controllerValues;
        this.valuesByController = data.values.reduce((acc, v) => {
            v.validFor.forEach(idx => {
                const key = Object.keys(this.controllerMap)[idx];
                (acc[key] = acc[key] ?? []).push({ label: v.label, value: v.value });
            });
            return acc;
        }, {});
    }
}

Pattern: Deploying the matrix

valueSettings blocks must include every (controllingValue, dependentValue) pair that should be enabled. Omitted pairs are disabled.

Decision Guidance

Recommended Workflow

1. Confirm controlling field is picklist or checkbox (not multi-select, text, or number).
2. Build the matrix in Setup → Field Dependencies, or author valueSettings in XML.
3. For every integration path (API, Data Loader, Apex), add a Validation Rule or Before-Save automation to enforce the matrix.
4. For custom LWC, use getPicklistValues not hardcoded arrays.
5. Write a test inserting an invalid combination via Apex — assert the Validation Rule fires.
6. Document the matrix in the field description (help text is limited to 255 chars; use description).
7. Deploy as a unit — dependent picklist XML must include all valueSettings.

Review Checklist

• Controlling field is picklist or checkbox
• valueSettings matrix covers all intended combinations
• Validation Rule OR Before-Save enforces matrix on API writes
• LWC custom components use getPicklistValues, not hardcoded values
• Record Type picklist assignment updated for new values
• Apex test covers invalid-combination insert via API

Salesforce-Specific Gotchas

1. API writes bypass dependency enforcement. Without a Validation Rule, a bad combination inserts cleanly, and later breaks UI views ("invalid picklist value").
2. Adding a new value to the controlling picklist does NOT automatically enable it — you must edit valueSettings to enable the dependent values.
3. Record Types filter first. A value disabled at the Record Type level is unreachable regardless of dependency matrix.
4. Multi-select picklist cannot be a controlling field. Use a workaround with a normal picklist that captures the primary selection.
5. Reporting filters don't respect dependencies — a stale invalid combination shows up unless you filter explicitly.
6. getPicklistValues wire adapter is recordType-aware — passing master record type (012000000000000AAA) returns all values regardless of RT restrictions.

Output Artifacts

Related Skills

• admin/record-types-and-page-layouts — RT-level picklist filtering layers on top
• admin/validation-rules — enforcing matrix via VR
• lwc/lwc-wire-refresh-patterns — getPicklistValues wire behavior