Tags for questions related to validating data.

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497
votes
1answer
62k views

Is the use of “utf8=✓” preferable to “utf8=true”?

I have recently seen a few URIs containing the query parameter "utf8=✓". My first impression (after thinking "mmm, looks cool") was that this could be used to detect a broken character encoding. So, ...
90
votes
25answers
20k views

How far should one take e-mail address validation?

I'm wondering how far people should take the validation of e-mail address. My field is primarily web-development, but this applies anywhere. I've seen a few approaches: simply checking if there is ...
41
votes
8answers
4k views

Should I throw an exception in case of a meaningful value outside of the range or handle it myself?

I have written a struct that represents latitude/longitude coordinates. Their values range from -180 to 180 for longtitudes and 90 to -90 for lattitudes. If a user of that struct gives me a value ...
31
votes
21answers
7k views

Is Software Testing Really Needed?

I'm a student working on my B.E(CS) and my question is the following: Is testing in the software field needed? If we create a software with great care, then why should we test? After testing can ...
29
votes
7answers
4k views

Should I validate a method call's return value even if I know that the method can't return bad input?

I'm wondering if I should defend against a method call's return value by validating that they meet my expectations even if I know that the method I'm calling will meet such expectations. GIVEN User ...
25
votes
3answers
8k views

Where we should put validation for domain model

I still looking best practice for domain model validation. Is that good to put the validation in constructor of domain model ? my domain model validation example as follows: public class Order { ...
23
votes
4answers
3k views

Is client-side validation really all that important, always? [duplicate]

Through the years I've worked in web development it's been ingrained in me that client-side validation is absolutely and completely necessary in all web applications. Seems to me like all the people ...
23
votes
10answers
16k views

Constructor parameter validation in C# - Best practices

What is the best practice for constructor parameter validation? Suppose a simple bit of C#: public class MyClass { public MyClass(string text) { if (String.IsNullOrEmpty(text)) ...
22
votes
10answers
10k views

Should a method validate its parameters? [duplicate]

Say you are designing a Square root method sqrt. Do you prefer to validate the parameter passed is not a negative number or do you leave it up to the caller to make sure the param passed is valid. How ...
20
votes
5answers
4k views

Data input validation - Where? How much? [closed]

Data input validation always was quite an internal struggle to me. On the verge of adding a real security framework and code to our legacy application rewrite project (which so far pretty much keeps ...
19
votes
9answers
2k views

Is an 'if password == XXXXXXX' enough for minimum security?

If I create a login for an app that has middle to low security risk (in other words, its not a banking app or anything), is it acceptable for me to verify a password entered by the user by just saying ...
18
votes
4answers
772 views

Is validating HTML a thing of the past? [duplicate]

With us moving continually closer to HTML5 in terms of adoption, is writing HTML for validity something the web is rejecting, allowing us to straddle standards as the web continues to be in a ...
14
votes
7answers
7k views

When should pointers be checked for NULL in C?

Summary: Should a function in C always check to make sure it is not dereferencing a NULL pointer? If not when is it appropriate to skip these checks? Details: I've been reading some books about ...
12
votes
5answers
1k views

For an ORM supporting data validation, should constraints be enforced in the database as well?

I have always applied constraints at the database level in addition to my (ActiveRecord) models. But I've been wondering if this is really required? A little background I recently had to unit test a ...
12
votes
5answers
914 views

Strengthening code with possibly useless exception handling

Is it a good practice to implement useless exception handling, just in case another part of the code is not coded correctly? Basic example A simple one, so I don't loose everybody :). Let's say I'm ...
10
votes
6answers
2k views

How should I handle invalid user input?

I have been thinking about this issue for a while and I would be curious to have opinions from other developers. I tend to have a very defensive style of programming. My typical block or method looks ...
10
votes
3answers
3k views

Validation and authorization in layered architecture

I know you are thinking (or maybe yelling), "not another question asking where validation belongs in a layered architecture?!?" Well, yes, but hopefully this will be a little bit of a different take ...
10
votes
2answers
4k views

Has anyone successfully used Windows Workflow for a Business Rules/Validation engine?

I was wondering if anyone has successfully used Windows Workflow Foundation for a BusinessRules/Validation engine, or if you know of some sample code or articles about this. If you have used it ...
9
votes
5answers
5k views

Do you use both Client-side and Server-side validation techniques?

Do you use both Client-side and Server-side validation techniques side by side when validating input from a user, e.g. via a contact form? If so, is it really necessary? Are you over engineering?
9
votes
4answers
786 views

How defensive should we be?

We've been running Pex over some code, and it has been showing some good things (well bad things, but showing them before it gets to production!). However, one of the nice things about Pex is that it ...
9
votes
3answers
3k views

IValidatableObject vs Single Responsibility

I like the extnesibility point of MVC, allowing view models to implement IValidatableObject, and add custom validation. I try to keep my Controllers lean, having this code be the only validation ...
9
votes
1answer
597 views

Better to use error monad with validation in your monadic functions, or implement your own monad with validation directly in your bind?

I'm wondering what's better design wise for usability/maintainability, and what's better as far as fitting with the community. Given the data model: type Name = String data Amount = Out | Some | ...
8
votes
5answers
9k views

What Special characters should one allow for a Phone Number?

So I am designing a webpage which will be used for global users, includes users from Canada, US, India, UK etc. I need to apply validations for this phone number field, but I'm not sure the best way ...
8
votes
3answers
754 views

How come verification does not include actual testing?

Having read a lot about this topic --- such as on this Software Testing Fundamentals site on verification and validation and Software Testing and Quality Assurance: Theory and Practice by Naik and ...
8
votes
2answers
2k views

Where to validate domain model rules that depend on database content?

I'm working on a system that allows Administrators to define Forms that contain Fields. The defined Forms are then used to enter data to the system. Sometimes the Forms are filled by a human via a GUI,...
8
votes
1answer
2k views

Duck typing, data validation and assertive programming in Python

About duck typing: Duck typing is aided by habitually not testing for the type of arguments in method and function bodies, relying on documentation, clear code and testing to ensure correct use. ...
8
votes
2answers
4k views

Command handlers and DDD

I have an ASP.NET MVC application, that uses a query service to get data and a command service to send commands. My question is about the command part. If a request comes in, the command service uses ...
7
votes
2answers
622 views

What is best practice to handle whitespaces when letting the user edit the configuration, the name=value pairs?

For instance, you let the user define the notorious path variable. How do you interpret apppath = C:\Program Files\App? This looks like a programming language adopted practice to ignore the white ...
7
votes
6answers
2k views

If the model is validating the data, shouldn't it throw exceptions on bad input?

Reading this SO question it seems that throwing exceptions for validating user input is frowned upon. But who should validate this data? In my applications, all validations are done in the business ...
7
votes
4answers
2k views

Managing client-side and server-side validations in one place

I'm 100% on board with the case that one should definitely use both client-side and server-side data validations. However, in the frameworks and environments I've worked in, the approaches I've seen ...
7
votes
2answers
2k views

How is the Trial Period for Softwares generally implemented?

I was always under the assumption that trial softwares write a registry value of the installation date and then the software makes a comparison of the current date of the system with the remaining ...
7
votes
3answers
376 views

How to measure external quality of software

For my thesis, I am doing research into the characteristics of Behavior Driven Development (BDD). One of the BDD claims is that by specifying the requirements in a ubiquitous language together with ...
7
votes
2answers
125 views

How to work with/around an API that does not return errors?

I am currently working on a project which requires data fetching from a 3rd party closed API (over SOAP). Currently I'm in a situation where I have to do argument and data validation inside our ...
6
votes
4answers
1k views

Validating User Stories: How much change is too much?

While the core of requirements development and acceptance criteria would ideally take place during the planning meeting in order to create a better estimate, Scrum encourages continuous interaction ...
6
votes
2answers
266 views

Data validation: separated class or not?

When I have a lot of data that needs to be validated, should I create a new class for the sole purpose of validation or should I stick with in-method validation? My particular example contemplates a ...
5
votes
2answers
1k views

Is server validation necessary with client-side validators?

I recently created a .net web app that used over 200 custom validators on one page. I wrote code for both ClientValidationFunction and OnServerValidate which results in a ton of repetitive code. My ...
5
votes
4answers
503 views

How far should I take email address validation when the cost of bad emails is high?

When it's more important to prevent typos than to cover 100% of all possible email addresses, what syntactic email validations do you do? Imagine this: You're with the local gas & electric ...
5
votes
8answers
475 views

Do objects with validation logic in their domain really represent their real world counterparts?

I asked a question about whether validation behavior should be treated the same as other types of behavior in regard to the concept of OOP being "data + behavior". I got some good answers back that ...
5
votes
3answers
191 views

Name for sanitizing at the right time?

Recently we had an issue on our site where someone attempted SQL injection via a cookie (we'll call it lastID). NOC was in a frenzy and angry about how the cookie as an attack vector could be ignored....
5
votes
5answers
847 views

Is realtime validation of username good or bad?

I have a simple form for the user to sign up to my site; with email, username and password fields. We are now trying to implement an ajax validation so the user doesn't have to post the form to find ...
5
votes
5answers
1k views

In a web application backed by a database, how often should I validate data? [duplicate]

Possible Duplicate: Data input validation - Where? How much? Given that I have a web application with a user facing form that will store information in a database (that will be used by other ...
5
votes
8answers
1k views

Data validation best practices: how can I better construct user feedback?

Data validation, whether it be domain object, form, or any other type of input validation, could theoretically be part of any development effort, no matter its size or complexity. I sometimes find ...
5
votes
4answers
464 views

Can data classes contain methods for validation?

OK, say I have a data class for a user: public class User { private String firstName; private String lastName; private long personCode; private Date birthDate; private Gender gender; private String ...
5
votes
2answers
242 views

Where should business logic go in a layered architecture?

First of all, i'm not talking about validation in the sense of the nullability or length of a field like in this and this questions where we can use isValid() methods in business classes or an ...
4
votes
4answers
497 views

Should validation messages contain punctuation? [closed]

When building an application should all validation messages have punctuation?
4
votes
6answers
4k views

Validation of the input parameter in caller: code duplication?

Where is the best place to validate input parameters of function: in caller or in function itself? As I would like to improve my coding style, I try to find the best practices or some rules for this ...
4
votes
2answers
439 views

What is the best way to validate the following data?

Lets say I receive an xml request that is sent to my web service and this request contains some data in it such as Hotel Room/Rate pairs (Room = Double Queen, Rate = 10%). The database has all of ...
4
votes
1answer
206 views

Writing a valid test case for validating XMLs

How would I write a unit test, say JUnit, for validating an XML file? I have an application that creates a document as an XML file. In order to validate this XML structure, do I need to create an XML ...
4
votes
3answers
858 views

Java & REST API: How do I check for duplicate before inserting record?

I am developing an application in Java to parse and upload records from a CSV to an online database, via a REST API. While I know for sure that there are no duplicate records in each CSV file, I ...
4
votes
4answers
6k views

Best way of validating Class properties

Background: I have a CSV file, which I need to ready and validate each element in each row and create a collection of a class, having valid data. i.e CSV File looks like: EmpID,FirstName,...