Re: Validation and Data storing in one step - C# Discussion Boards

28-Jan-14 17:47

I am reading file and after validation i am saving data in properties
Now i was hoping to use properties for validation and then save if validation succeed for e.g.

const string AN2Mandatory = @"[a-zA-Z@$^&#0-9\s\S]{2}";
const string AN70Optional = @"[a-zA-Z@$^&#0-9\s\S]{70}";

these are for validations
and these are properties

public string VersionNumber { get; set; }
public string ClientName { get; set; }

this is sample logic

Match m = Regex.Match(Line, AN70Optional);
VersionNumber = m.Value;

can i apply attributes or something so that while puting value in property my validation is evaluated first and then fill property. instead of validating separately and then storing it

Kornfeld Eliyahu Peter28-Jan-14 20:17

28-Jan-14 20:17

I can offer you two ways...
1 - Put the validation into the property setter (simple).
2 - Write (or find) an attribute that gets the regex as parameter and validates the property decorated with (much powerful).

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion28-Jan-14 20:27

28-Jan-14 20:27

i am also trying the 2 approach and for that i have to write a custom attribute.

Kornfeld Eliyahu Peter28-Jan-14 20:31

28-Jan-14 20:31

Great - when you ready made it into an article to share with all!!!

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion28-Jan-14 20:38

28-Jan-14 20:38

This is a win form application

i have created a class

public class ValidateProperty : Attribute
{
string _pattern;
bool _mandatory;
public ValidateProperty(string Pattern, bool Mandatory = false)
{
_pattern = Pattern;
_mandatory = Mandatory;
}

public override bool Match(object obj)
{
Match m = Regex.Match((string)obj, _pattern);
if (_mandatory == true)
{
if (string.IsNullOrWhiteSpace(m.Value)) return false;
else
{
return true;
}
}
else
return true;
}
}

and then applied on property

[ValidateProperty(@"[a-zA-Z@$^�-9\s\S]{70}",true)]
public string ClientName { get; set; }

but it is not validating when i put a string with less than 70 char. even in debug mode code is not going to match function

Kornfeld Eliyahu Peter28-Jan-14 20:41

28-Jan-14 20:41

{70} doesn't mean exactly 70, but up to 70!!!
The correct format of {} is {m,n} where m is from and n is to...
When you use only one number it interpreted as {0,n}.
For exactly 70 characters try {70,70}!!!

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion28-Jan-14 20:43

28-Jan-14 20:43

yeah that's fine but issue is that it is not fired even if i pass null or less than 70 char
less than 70 so it should return false or should not accept value in that property.

but currently it is not happenin

Kornfeld Eliyahu Peter28-Jan-14 20:45

28-Jan-14 20:45

You attribute's Match method got hit?

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion28-Jan-14 20:46

28-Jan-14 20:46

No it does not get hit.

ClientName="dd";

Kornfeld Eliyahu Peter28-Jan-14 20:50

28-Jan-14 20:50

Go and read this: http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.validationattribute(v=vs.110).aspx[^]

It may also bee of interest:
http://msdn.microsoft.com/en-us/library/ff649907.aspx[^]
http://msdn.microsoft.com/en-us/library/ee707335(v=vs.91).aspx[^]

And also read some regex - yours is a mess...

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion28-Jan-14 23:18

28-Jan-14 23:18

this is good thanks but data i will have is something like this
RA01XYZ 201401231445012345611012345678998765432101234DESTINATIONNAMESIZEIS70

RA is one field
01 is one field
XYZ is on and so on

so i will have to extract and then validate
any suggestions

Kornfeld Eliyahu Peter28-Jan-14 23:21

28-Jan-14 23:21

With regex you can validate without breaking it apart...

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion28-Jan-14 23:22

28-Jan-14 23:22

yeah but then we will have to validate through regex and store it in property separately
i guess this is what they call catch 22 Wink | ;)

Kornfeld Eliyahu Peter28-Jan-14 23:31

28-Jan-14 23:31

I think not.
You should pass the regex as a property to your new attribute...

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion28-Jan-14 23:37

28-Jan-14 23:37

that's what i am doing
but see
i need to first
extract
validate
store

[RegexValidator(@"[a-zA-Z@$^�-9\s\S]{2}", ErrorMessage = "ok")]
public string RecordType { get; set; }

[RegexValidator(@"[a-zA-Z@$^�-9\s\S]{2}",ErrorMessage="ok1")]
public string VersionNumber { get; set; }

[StringLengthValidator(1, 50, MessageTemplate = "Last Name must be between 1 and 70 characters")]
public string ClientName { get; set; }

-----------------
string Line="RA01XYZ 201401231445012345611012345678998765432101234DESTINATIONNAMESIZEIS70 SENDINGENTITYIDENTIFIER SENDERNAMESIZE70 ";
p.RecordType = Line;
p.VersionNumber = Line;

Now issue is that it will always start from 1 character it will not increment
RecordType will start from 1 to 2
so VersionNumber should start from 3 to 4
and ClientName from 5 to 50

i guess i'll try mentioning this using StringLength validator but then datatype validation will be a case

Kornfeld Eliyahu Peter29-Jan-14 0:16

29-Jan-14 0:16

I see.
For that you have to write an other class/method to split the string into fields...
You may use these:
http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.structlayoutattribute(v=vs.110).aspx[^]
http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.fieldoffsetattribute(v=vs.110).aspx[^]

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

nitin_ion29-Jan-14 21:09

29-Jan-14 21:09

thanks

now i guess i cant do evs in one step so i am extracting first using substring
and then validating and storing using attributes [EL]

[RegexValidator(@"[a-zA-Z@$^�-9\S]{2}", MessageTemplate = "RecordType Validation failed")]

Matt T Heffron29-Jan-14 10:24

Matt T Heffron

29-Jan-14 10:24

Just attaching a custom attribute to the property doesn't automatically cause some validation.
You must have something that looks for an "appropriate" attribute, using Reflection, typically, and causes the actual validation.

Kornfeld Eliyahu Peter29-Jan-14 21:49

29-Jan-14 21:49

See here...
http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.validationattribute(v=vs.110).aspx[^]

I'm not questioning your powers of observation; I'm merely remarking upon the paradox of asking a masked man who he is. (V)

Matt T Heffron30-Jan-14 6:38

Matt T Heffron

30-Jan-14 6:38

I see...
However, the OP didn't derive from ValidationAttribute, they derived directly from Attribute:

public class ValidateProperty : Attribute

and that's NOT going to work.

Kornfeld Eliyahu Peter30-Jan-14 6:42