AndroidFormEnhancer

AndroidFormEnhancer is a library for implementing input forms easily in the Android application. You can use annotations to describe the definitions of the input form briefly, reduce codes that handle data of the screens in the Activities and Fragments.

Install

The 'library' folder is the main library. Please import it into the Eclipse or other IDEs.

Usage

1. Create POJO class of the input form, define public fields and add annotations to them.

   public class DefaultForm {
       @Widget(id = R.id.textfield_name)
       @Required
       public String name;
   
       @Widget(id = R.id.textfield_age, validateAfter = R.id.textfield_name)
       @IntType
       public String age;
   }
   

2. If you use types other than String, create an entity class which fields has the same names as the form class.

   public class DefaultEntity {
       public String name;
       public int age;
   }
   

3. Write the codes like following to the Activity or Fragment to extract data from the screen, validate them and convert types.

   ValidationResult result = new FormHelper(DefaultForm.class, this).validate();
   if (result.hasError()) {
       // Show error messages
       Toast.makeText(this, result.getAllSerializedErrors(), Toast.LENGTH_SHORT).show();
   } else {
       // This entity object has clean and converted data
       DefaultEntity entity = helper.create(DefaultEntity.class);
   }
   

4. If you want to validate as soon as the focus changed, just write these codes:

   new FormHelper(DefaultForm.class, this).setOnFocusOutValidation();
   

   Note that this method affects only for the text fields.

Get input values

To get input values from the layouts, create a Form class at first. Form class is just a POJO class, which has public fields. All the fields must be public and their types must be String or java.util.List<String>.

public class DefaultForm {
    public String name;
}

Each fields must be related to the widgets like android.widget.EditText. To create relationship with widgets, add special annotations to the fields.

EditText

If you use <EditText>, then just use @Widget for the related field of the Form class. For example, if the part of your res/layout/some_layout.xml is like this:

<EditText
    android:id="@+id/textfield_name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

then you should define your Form class like this:

public class DefaultForm {
    @Widget(id = R.id.textfield_name)
    public String name;
}

RadioGroup and RadioButton

If you use <RadioGroup> and <RadioButton>, and you want to validate whether the one of the radio buttons is checked or not, then use @Widget and @WidgetValue for the related field of the Form class. For example, if the part of your res/layout/some_layout.xml is like this:

<RadioGroup
    android:id="@+id/rg_gender"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    <RadioButton
        android:id="@+id/rb_male"
        android:text="Male"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <RadioButton
        android:id="@+id/rb_female"
        android:text="Female"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</RadioGroup>

then you should define your Form class like this:

public class DefaultForm {
    @Widget(id = R.id.rg_gender,
        values = {
            @WidgetValue(id = R.id.rb_male, value = "M"),
            @WidgetValue(id = R.id.rb_female, value = "F"),
        })
    public String gender;
}

If you choose radio button "Male", then the value of the DefaultForm#gender will be "M".

CheckBox

If you use <CheckBox> and you want to validate that at least one check box is checked, then use @Widget and @WidgetValue for the related field of the Form class. For example, if the part of your res/layout/some_layout.xml is like this:

<LinearLayout
    android:id="@+id/cbg_sns"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <CheckBox
        android:id="@+id/cb_facebook"
        android:text="Facebook"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <CheckBox
        android:id="@+id/cb_googleplus"
        android:text="Google+"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <CheckBox
        android:id="@+id/cb_twitter"
        android:text="Twitter"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

then you should define your Form class like this:

public class DefaultForm {
    @Required(atLeast = 1)
    @Widget(id = R.id.cbg_sns,
        values = {
            @WidgetValue(id = R.id.cb_facebook, value = "FB"),
            @WidgetValue(id = R.id.cb_googleplus, value = "GP"),
            @WidgetValue(id = R.id.cb_twitter, value = "TW")
        })
    public List<String> sns;
}

If you choose check boxes "Facebook" and "Google+", then the value of the DefaultForm#sns will be List<String> which has 2 items "FB" and "GP". Note that @Widget is used just for grouping same kind of CheckBoxes, so the other ViewGroup's subclasses than LinearLayout like RelativeLayout can be related to @Widget.

Spinner

If you use <Spinner>, then just use @Widget for the related field of the Form class. For example, if the part of your res/layout/some_layout.xml is like this:

<Spinner
    android:id="@+id/spn_credit_card_type"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

then you should define your Form class like this:

public class DefaultForm {
    @Widget(id = R.id.spn_credit_card_type)
    public String creditCardType;
}

If you want to use the head item as a dummy text like "Please select", then add @Required annotation and set Required#otherThanHead to true. Then you can check whether the user selected other than the head item or not.

Validations

Following validation classes are available:

1. RequiredValidator

   • Validates the EditText's value is not null nor empty string.
   • The target fields must have field in Form class with @Required.

   • If you need value with some conditions, use @When as follows:

     public class CustomRequiredWhenForm {
         @Widget(id = R.id.spn_reason, nameResId = R.string.form_custom_required_when_reason)
         public String reason;
     
         @Widget(id = R.id.textfield_reason_other, nameResId = R.string.form_custom_required_when_reason_other,
                 validateAfter = R.id.spn_reason)
         @Required(when = {
             @When(id = R.id.spn_reason, equalsTo = "2")
         })
         public String reasonOther;
     }
     

     If the user select the 3rd option from the spinner R.id.spn_reason and the user does not input text field R.id.textfield_reason_other, then this validator assume it is an error.

2. IntTypeValidator

   • Validates the EditText's value whether it is a valid integer format.
   • The target fields must have field in Form class with @IntType.

3. FloatTypeValidator

   • Validates the EditText's value whether it is a valid float format.
   • The target fields must have field in Form class with @FloatType.

4. MaxValueValidator

   • Validates the EditText's value whether it is less than or equals to the specified value.
   • The target fields must have field in Form class with @MaxValue.

5. MinValueValidator

   • Validates the EditText's value whether it is more than or equals to the specified value.
   • The target fields must have field in Form class with @MinValue.

6. IntRangeValidator

   • Validates the EditText's value whether it is in the specified range: the minimum value is IntRange#min() and the maximum value is IntRange#max().
   • The target fields must have field in Form class with @IntRange.

7. DigitsValidator

   • Validates the EditText's value whether it consists only of digits (which means 0 through 9).
   • The target fields must have field in Form class with @Digits.

8. AlphabetValidator

   • Validates the EditText's value whether it consists only of ASCII alphabet characters.
   • The target fields must have field in Form class with @Alphabet.
   • If you want to allow space character, set Alphabet#allowSpace() to true.

9. AlphaNumValidator

   • Validates the EditText's value whether it consists only of ASCII alphabet characters.
   • The target fields must have field in Form class with @AlphaNum.
   • If you want to allow space character, set AlphaNum#allowSpace() to true.

10. HiraganaValidator

    • Validates the EditText's value whether it consists only of Japanese Hiragana.
    • The target fields must have field in Form class with @Hiragana.

11. KatakanaValidator

    • Validates the EditText's value whether it consists only of Japanese Katakana.
    • The target fields must have field in Form class with @Katakana.

12. SinglebyteValidator

    • Validates the EditText's value whether it consists only of single-byte characters.
    • The target fields must have field in Form class with @Singlebyte.

13. MultibyteValidator

    • Validates the EditText's value whether it consists only of multi-byte characters.
    • The target fields must have field in Form class with @Multibyte.

14. LengthValidator

    • Validates the EditText's value whether it has the specified length.
    • The target fields must have field in Form class with @Length.

15. MaxLengthValidator

    • Validates the EditText's value whether its length is less than or equals to the specified length.
    • The target fields must have field in Form class with @MaxLength.

16. NumOfDigitsValidator

    • Validates the EditText's value whether its length is the specified length.
    • The target fields must have field in Form class with @NumOfDigits.
    • This validator resembles to the LengthValidator, but this validator does not treat as an error if the value includes non-digit character even though its length does not match NumOfDigits#value().

17. MaxNumOfDigitsValidator

    • Validates the EditText's value whether its length is less than or equals to the specified length.
    • The target fields must have field in Form class with @MaxNumOfDigits.
    • This validator resembles to the MaxLengthValidator, but this validator does not treat as an error if the value includes non-digit character even though its length exceeds MaxNumOfDigits#value().

18. DatePatternValidator

    • Validates the EditText's value with date format.
    • The target fields must have field in Form class with @DatePattern.
    • Date format used in validation is java.text.DateFormat.SHORT, which will change with locale.
    • If you want to use custom format, use DatePattern#value().

19. PastDateValidator

    • Validates the EditText's value is valid date format and past date.
    • The target fields must have field in Form class with @PastDate.
    • Date format used in validation is java.text.DateFormat.SHORT, which will change with locale.
    • If you want to use custom format, use PastDate#value().
    • If you do not want to assume today as an error, set PastDate#allowToday to true.

20. EmailValidator

    • Validates the EditText's value whether it is e-mail format.
    • The target fields must have field in Form class with @Email.
    • Pattern to be used in validation is this: ^[\\w-]+(\\.[\\w-]+)*@([\\w][\\w-]*\\.)+[\\w][\\w-]*$
    • If you want to use custom format, define your format in your style using afeValidatorDefinitions and afeCustomEmailPattern.

21. RegexValidator

    • Validates the EditText's value whether it matches the specified regular expression.
    • The target fields must have field in Form class with @Regex.
    • Regular expression must be specified by Regex#value().

Orders of the validation

Orders of the validation for each items are defined by Widget#validateAfter. For example, if you define form like following, the validators validate name at first, then validate age. Note that they are different from the orders in the screen.

public class DefaultForm {
    @Widget(id = R.id.textfield_name)
    @Required
    public String name;

    @Widget(id = R.id.textfield_age, validateAfter = R.id.textfield_name)
    @IntType
    public String age;
}

Customizations

You can customize the behaviours and messages like following:

1. Stop policy

   Stop policy controls the validators to continue or stop when they detected errors. For example, if you want to validate all the items and show all the errors, you should define your theme like this:

   <style name="YourTheme">
       <item name="afeValidatorDefinitions">@style/YourValidatorDefinitions</item>
   </style>
   
   <style name="YourValidatorDefinitions" parent="@style/AfeDefaultValidators">
       <item name="afeStopPolicy">continueAll</item>
   </style>
   

2. Available validations

   You can enable or disable the standard validators. You can also add your own validator. For example, if you want to use only the RequiredValidator, you should define your theme like this:

   <string-array name="your_standard_validators">
       <item>com.androidformenhancer.validator.RequiredValidator</item>
   </string>
   
   <style name="YourTheme">
       <item name="afeValidatorDefinitions">@style/YourValidatorDefinitions</item>
   </style>
   
   <style name="YourValidatorDefinitions" parent="@style/AfeDefaultValidators">
       <item name="afeStandardValidators">@array/your_standard_validators</item>
   </style>
   

3. Validation error messages

   You can override validation error messages. For example, if you want to override the error message for the RequiredValidator, You should define your theme like this:

   <string name="custom_msg_validation_required">You MUST fill in %1$s!</string>
   
   <style name="YourTheme">
       <item name="afeValidatorMessages">@style/YourValidatorMessages</item>
   </style>
   
   <style name="YourValidatorMessages">
       <item name="afeErrorRequired">@string/custom_msg_validation_required</item>
   </style>
   

   The name of the item used in the error message is the name of the field in Form class. If you want to change name, use annotation's nameResId attribute. For example, if you define field like:

   @Widget(id = R.id.textfield_name)
   @Required
   public String firstName;
   

   the error message will be "firstName is required". If you define Form like this:

   @Widget(id = R.id.textfield_name, nameResId = R.string.first_name)
   @Required
   public String firstName;
   

   or

   @Widget(id = R.id.textfield_name)
   @Required(nameResId = R.string.first_name)
   public String firstName;
   

   and define strings.xml like:

   <string name="first_name">First name</string>
   

   then the result will be "First name is required".

4. Error icons

   You can change validation error icons as follows:

   <style name="YourTheme">
       <item name="afeValidatorDefinitions">@style/YourValidatorDefinitions</item>
   </style>
   
   <style name="YourValidatorDefinitions" parent="@style/AfeDefaultValidators">
       <item name="afeValidationIconError">@drawable/your_icon_error</item>
       <item name="afeValidationIconOk">@drawable/your_icon_ok</item>
   </style>
   

ProGuard

If you want to use ProGuard, edit proguard-project.txt.

1. Keep class name of the Validators. This is always required.

   -keep class com.androidformenhancer.validator.* { <init>(...); }
   

2. Keep class members (public fields) of the Forms and Entities. If you use FormHelper#create() or @When, this is required.

   -keepclassmembers class com.androidformenhancer.sample.demos.DefaultForm {
     public *;
   }
   -keepclassmembers class com.androidformenhancer.sample.demos.DefaultEntity {
     public *;
   }
   

Samples

• Sample applications using this library are included in the samples folder.

Tests

• Test codes for JUnit test are included in the tests folder.

Developed By

• Soichiro Kashima - soichiro.kashima@gmail.com

License

Copyright 2012 Soichiro Kashima

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.