Android Input Validators

Not so long ago, I needed to add validators for input fields (EditText) to an android application, but nothing suitable was found on the network: I had to write my own. Now that everything is ready, you can distribute the results to everyone under the Apache license and tell you a little about how everything works. Those who are interested I ask under the cat.

Since everything was written from scratch, it was possible to make the architecture by itself, so the following scheme was chosen:

• One input field is assigned one validator (more is possible, but there is no point in it)
• Each validator is assigned several checkers for various conditions (text length, mask matching, etc.)
• Checkers perform checks in the order in which they were added, the first “failed” message shows.

For convenience, I made a couple of customizations:

• You can choose to check either by changing the text in the field, or manually
• You can show the message in a separate TextView, and the mechanism built into the android (red icon with a pop-up message).
• You can combine the validators into a group and initiate a check for the entire group, as well as show a separate message if at least one validator in the group detected an error.

The validators and checkers have base abstract classes, by implementing which you can get validators for your controls and your own special checks.

Now there are checks:

• On line emptiness
• For the length of the string
• Regexp matching
• Assign range (for integer input fields)
• Match text in another input field (useful for confirming passwords)

In the code, it all looks something like this:

//   ValidationSummary summaryValidator_ = new ValidationSummary(getString(R.string.common_error_message), headerErrorMessage); //      EditTextValidator firstnameValidator = new EditTextValidator(); //  EditText  ,     (  ,     ) firstnameValidator.setViewToValidate(firstnameEdit, ValidationMode.Manual); // TextView       ,       firstnameValidator.setExternalErrorView( (TextView) findViewById(R.id.firstname_error_text)); //     firstnameValidator.addConditionChecker(new NotEmptyChecker( getString(R.string.name_required_error_message) )); //   firstnameValidator.addConditionChecker(new LengthChecker(1, 50, getString(R.string.firstname_error_message) )); //    summaryValidator_.addValidator(firstnameValidator); ... //     EditTextValidator confirmPasswordValidator = new EditTextValidator(); confirmPasswordValidator.setViewToValidate(confirmPasswordEdit, ValidationMode.Manual); confirmPasswordValidator.setExternalErrorView( (TextView) findViewById(R.id.confirm_password_error_text)); //    ,    - passwordEdit confirmPasswordValidator.addConditionChecker(new TextMatchChecker(getString(R.string.confirm_password_error_message), passwordEdit)); summaryValidator_.addValidator(confirmPasswordValidator); 

')
You can initiate a check of all validators in a group by calling:

 summaryValidator_.performCheck(); 

All those who are interested in validators, I invite you to take a project from the GitHub of Rus Wizards , within which this code was written.
And, of course, any suggestions, suggestions, advice are welcome!