feat: add setFieldResult method to set external validation errors

build.gradle.kts

@@ -6,6 +6,6 @@ plugins {
 }
 
 allprojects {
-    version = "0.3.3"
+    version = "0.4.0"
     group = "de.thetadev.formconductor"
 }

compose-ui/src/main/java/de/thetadev/formconductor/composeui/scope/FormFieldScope.kt

@@ -9,7 +9,7 @@ import de.thetadev.formconductor.FieldResult
  *
  * @param V type of field value
  */
-interface FormFieldScope<V : Any?> {
+interface FormFieldScope<V> {
 
     /**
      * Observable State instance of field value
@@ -30,7 +30,19 @@ interface FormFieldScope<V : Any?> {
      *
      * You're encouraged to set the field value only using this function
      *
-     * @param input input value
+     * @param input Field value
+     * @param validate Validate the input on update
      */
     fun setField(input: V?, validate: Boolean = true)
+
+    /**
+     * A setter function for field value or error.
+     *
+     * Set the field value if the input is successful, fail validation if the input is an error.
+     *
+     * To be used for custom fields with built-in validation.
+     *
+     * @param input Field value or error
+     */
+    fun setFieldResult(input: Result<V?>)
 }

compose-ui/src/main/java/de/thetadev/formconductor/composeui/scope/FormFieldScopeImpl.kt

@@ -21,4 +21,8 @@ internal class FormFieldScopeImpl<V>(
     override fun setField(input: V?, validate: Boolean) {
         formField.setField(input, validate)
     }
+
+    override fun setFieldResult(input: Result<V?>) {
+        formField.setFieldResult(input)
+    }
 }

core/src/main/java/de/thetadev/formconductor/FormField.kt

@@ -50,10 +50,22 @@ interface FormField<V> {
      *
      * The function validates the field if the input is not **empty** or the field isn't **optional**
      *
-     * @param input
+     * @param input Field value
+     * @param validate Validate the input on update
      */
     fun setField(input: V?, validate: Boolean = true)
 
+    /**
+     * A setter function for field value or error.
+     *
+     * Set the field value if the input is successful, fail validation if the input is an error.
+     *
+     * To be used for custom fields with built-in validation.
+     *
+     * @param input Field value or error
+     */
+    fun setFieldResult(input: Result<V?>)
+
     /**
      * Validate the field without updating its value
      *

core/src/main/java/de/thetadev/formconductor/FormFieldImpl.kt

@@ -1,6 +1,7 @@
 package de.thetadev.formconductor
 
 import de.thetadev.formconductor.validation.optionalFlags.OptionalFlag
+import de.thetadev.formconductor.validation.rules.ExternalValidationErrorRule
 import de.thetadev.formconductor.validation.rules.OptionalRule
 import de.thetadev.formconductor.validation.validators.FieldValidator
 import de.thetadev.formconductor.validation.validators.StatelessFieldValidator
@@ -48,6 +49,7 @@ internal class FormFieldImpl<T : Any, V>(
         valueStream.value = input ?: defaultValue
 
         if (validate) {
+            if (hasExternalValidationError()) resultStream.value = FieldResult.NoInput
             validateField()
         } else if (input == null || input == "") {
             resultStream.value = FieldResult.NoInput
@@ -56,10 +58,23 @@ internal class FormFieldImpl<T : Any, V>(
         }
     }
 
+    override fun setFieldResult(input: Result<V?>) {
+        input.fold(
+            onSuccess = { setField(it) },
+            onFailure = {
+                resultStream.value =
+                    FieldResult.Error("Validation error", ExternalValidationErrorRule)
+            }
+        )
+    }
+
     /**
      * Validates the current input value and updates the field's result
      */
     override fun validateField(soft: Boolean) {
+        if (hasExternalValidationError()) {
+            return
+        }
         val input = valueStream.value
         // Null and empty strings are skipped for validation
         if (input != null && input != "") {
@@ -110,4 +125,9 @@ internal class FormFieldImpl<T : Any, V>(
             optionalStateEvaluators.all(OptionalFlag::evaluate)
         }
     }
+
+    private fun hasExternalValidationError(): Boolean {
+        val result = resultStream.value
+        return result is FieldResult.Error && result.failedRule is ExternalValidationErrorRule
+    }
 }

core/src/main/java/de/thetadev/formconductor/validation/rules/ExternalValidationErrorRule.kt

@@ -0,0 +1,3 @@
+package de.thetadev.formconductor.validation.rules
+
+object ExternalValidationErrorRule : ValidationRule

gradle/libs.versions.toml

@@ -1,5 +1,5 @@
 [versions]
-agp = "9.4.0"
+agp = "9.4.1"
 kotlinReflect = "1.7.10"
 kotlin = "2.4.10"
 kotlinxCoroutinesCore = "1.11.0"