Android Form EditText

Android form edit text is an extension of EditText that brings data validation facilities to the edittext.

Example App

I built an example app that showcase some of the possibilities of the library.

You'll be able to find the app in the Play Store Here some screenshot of the Example app ( and the library )

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The app source code is located under this repo!

How to use

In your xml import an extra namespace on the root of your layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:whatever="http://schemas.android.com/apk/res/your.package.name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >
    ....
    <!-- Your actual layout -->
    ....
</LinearLayout>

Note: It's not mandatory to use it on the root element. Also remember to change the xmlns value with your package name

Whenever you need to use the FormEditText just do the following in your xml.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:whatever="http://schemas.android.com/apk/res/your.package.name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <!-- Some stuff -->

	<com.andreabaccega.widget.FormEditText
           whatever:testType="alpha"
           android:id="@+id/et_firstname"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           />    

    <!-- Some other stuff -->

</LinearLayout>

As you noticed there is a whatever:test attribute setted to alpha. This let the FormEditText know that the data inside it should be only Alpha characters.

There are several values you can set to the test attribute:

• regexp: for custom regexp
• numeric: for an only numeric field
• alpha: for an alpha only field
• alphaNumeric: guess what?
• email: checks that the field is a valid email
• creditCard: checks that the field contains a valid credit card using Luhn Algorithm
• phone: checks that the field contains a valid phone number
• domainName: checks that field contains a valid domain name ( always passes the test in API Level < 8 )
• ipAddress: checks that the field contains a valid ip address
• webUrl: checks that the field contains a valid url ( always passes the test in API Level < 8 )
• nocheck: It does not check anything except the emptyness of the field.

For most of the test type values this library comes with a couple of default strings. This means that error strings ( english only ) are already available for the following test types: numeric, alpha, alphanumeric

You can customize them using the attributes

• testErrorString used when the field does not pass the test
• emptyErrorString used when the field is empty

Example:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:whatever="http://schemas.android.com/apk/res/your.package.name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <!-- Some stuff -->

	<com.andreabaccega.widget.FormEditText
           whatever:testType="alpha"
           whatever:emptyErrorString="@string/your_name_cannot_be_empty"
           whatever:testErrorString="@string/your_name_is_ugly"
           android:id="@+id/et_firstname"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           />    

    <!-- Some other stuff -->

</LinearLayout>

Furthermore you can ask the FormEditText to allow the content to be optional. Just use the emptyAllowed attribute and set it to true. Note: If you don't specify the emptyAllowed attribute the default value is false.

If you want to use regexp as test attribute value you'll need to also use the customRegexp attribute. Take a look in the following example:

Example: (Email check)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:whatever="http://schemas.android.com/apk/res/your.package.name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <!-- Some stuff -->

	<com.andreabaccega.widget.FormEditText
           whatever:testType="regexp"
           whatever:customRegexp="^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$"
           whatever:testErrorString="@string/error_emailnotvalid"
           android:id="@+id/et_email"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:hint="@string/hint_email"
           android:inputType="textEmailAddress"
           />    

    <!-- Some other stuff -->

</LinearLayout>

Note: The library supports the email check natively using the email value as the test attribute.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:whatever="http://schemas.android.com/apk/res/your.package.name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <!-- Some stuff -->

	<com.andreabaccega.widget.FormEditText
           whatever:testType="email"
           android:id="@+id/et_email"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:hint="@string/hint_email"
           android:inputType="textEmailAddress"
           />    

    <!-- Some other stuff -->

</LinearLayout>

In your Java code you'll need to call a method when you want to know if the field validates.

	public void onClickNext(View v) {
		FormEditText[] allFields	= { etFirstname, etLastname, etAddress, etZipcode, etCity };
		
		
		boolean allValid = true;
		for (FormEditText field: allFields) {
			allValid = field.testValidity() && allValid;
		}
		
		if (allValid) {
			// YAY
		} else {
			// EditText are going to appear with an exclamation mark and an explicative message.
		}
	}

Calling testValidity() will cause the EditText to cycle through all the validators and call the isValid method. it will stop when one of them returns false or there are no validators left.

Furthermore testValidity() will also place an exclamation mark on the right of the EditText and will call the setError method.

Add your custom validators

You can add your custom validators runtime through the addValidator method. For example, let's suppouse we want to add a validator that checks that the text input is equal to the string "ciao":

public class CiaoValidator extends Validator {

	public CiaoValidator() {
		super("You should enter 'ciao' here");
	}

	public boolean isValid(EditText et) {
		return TextUtils.equals(et.getText(), "ciao");
	}
	
}

As you can see in the constructor you'll be required to set an Error Message that will be handled ( in this simple scenario ) by the super class. That piece of code will set the error message to: You should enter 'ciao' here.

This means that if the user will not enter "ciao" in the edit text it will get that error message in the popup.

Binary operators

You can use the following binary operators in order to perform checks on the field value:

• AND: will return true if every enqueued validator returns true
• OR: will return true if just one enqueued validator returns true
• NOT: will return the inverse of the passed Validator

With these binary operator validators you'll be able to perform as many different checks as you want. For example, lets say you want a field to be valid either if the user enters his email address or his credit card. Use 'nocheck' in the xml and programmatically do something like this:

  protected void onCreate(Bundle savedInstanceState) {
    // Blabla

    FormEditText fdt = (FormEditText) findViewById(R.id.et);
    fdt.addValidator(
        new OrValidator(
            "This is neither a creditcard or an email", 
            new CreditCardValidator(null), // we specify null as the message string cause the Or validator will use his own message  
            new EmailValidator(null) // same here for null
            )
        );
  }

Author

• Andrea Baccega [email protected] - Author/Ideator of the library