Merge pull request #63 from mathielo/single_field_validation

Single field validation

README.md

@@ -108,6 +108,26 @@ func validationFailed(errors:[UITextField:ValidationError]) {
 
 ```
 
+### Single Field Validation
+
+You may use single field validation in some cases. This could be useful in situations such as controlling responders:
+
+```swift
+// Don't forget to use UITextFieldDelegate
+// and delegate yourTextField to self in viewDidLoad()
+func textFieldShouldReturn(textField: UITextField) -> Bool {
+    validator.validateField(textField){ error in
+        if error == nil {
+            // Field validation was successful
+        } else {
+            // Validation error occurred
+        }
+    }
+    return true
+}
+```
+
+
 ## Custom Validation 
 
 We will create a ```SSNRule``` class to show how to create your own Validation. A United States Social Security Number (or SSN) is a field that consists of XXX-XX-XXXX. 

SwiftValidator/Core/Validator.swift

@@ -47,6 +47,26 @@ public class Validator {
         }
     }
     
+    // MARK: Public functions
+    
+    public func validateField(textField: UITextField, callback: (error:ValidationError?) -> Void){
+        if let fieldRule = validations[textField] {
+            if let error = fieldRule.validateField() {
+                if let transform = self.errorStyleTransform {
+                    transform(validationError: error)
+                }
+                callback(error: error)
+            } else {
+                if let transform = self.successStyleTransform {
+                    transform(validationRule: fieldRule)
+                }
+                callback(error: nil)
+            }
+        } else {
+            callback(error: nil)
+        }
+    }
+    
     // MARK: Using Keys
     
     public func styleTransformers(success success:((validationRule:ValidationRule)->Void)?, error:((validationError:ValidationError)->Void)?) {

SwiftValidatorTests/SwiftValidatorTests.swift

@@ -211,6 +211,18 @@ class SwiftValidatorTests: XCTestCase {
         }
     }
     
+    func testValidateSingleField() {
+        REGISTER_VALIDATOR.registerField(REGISTER_TXT_FIELD, rules: [EmailRule()])
+        REGISTER_TXT_FIELD.text = VALID_EMAIL
+        REGISTER_VALIDATOR.validateField(REGISTER_TXT_FIELD) { error in
+            XCTAssert(error == nil, "Should not present error")
+        }
+        REGISTER_TXT_FIELD.text = INVALID_EMAIL
+        REGISTER_VALIDATOR.validateField(REGISTER_TXT_FIELD) { error in
+            XCTAssert(error?.errorMessage.characters.count > 0, "Should state 'invalid email'")
+        }
+    }
+    
     // MARK: Validate error field gets it's text set to the error, if supplied
     
     func testNoErrorMessageSet() {

Validator/ViewController.swift

@@ -78,4 +78,18 @@ class ViewController: UIViewController , ValidationDelegate, UITextFieldDelegate
     func hideKeyboard(){
         self.view.endEditing(true)
     }
+    
+    // MARK: Validate single field
+    // Don't forget to use UITextFieldDelegate
+    func textFieldShouldReturn(textField: UITextField) -> Bool {
+            validator.validateField(textField){ error in
+                if error == nil {
+                    // Field validation was successful
+                } else {
+                    // Validation error occurred
+                }
+            }
+        return true
+    }
+
 }