Validate value in field - xpages

Question

Is there anyway to check when you type in to a field if there already are any document saved with that value in that field. Ex, if you type projectno i want to check if any other document already have that projectno. Any suggestion how i will validate that
Regards

Answer 1

You need a view in the database that is sorted in the first column by the field that you are using. I will assume it is a hidden view, called "(lookupUnique)". Build it and test it to make sure it is showing the field that you want in the first column, and that the values are sorted.
Now you need a way to do a lookup into this view. Ideally, you're wanting the lookup to fail -- because there is no document with the same value, in which case you allow the save to continue. But there's one other case where you might want to allow the save to continue. That's the case where the lookup succeeds because the lookup found the document that you are working on right now, which was previously saved and therefore is found in the view, and a user is now editing it again.
The #DbLookup function with the [RETURNDOCUMENTUNIQUEID] and [FAILSILENT] arguments is the IBM-recommended solution for this. I.e.,
foundId := #DbLookup("Notes":"NoCache";"":"";"(lookupUniqe)";theUniqueFieldNameGoesHereWithoutQuotes;1;[RETURNDOCUMENTUNIQUEID]);
If this formula returns "", then no match was found, therefore your code should return #Success to let the save continue. If it returns anything else, then compare the result with #DocumentUniqueId. If they match, then your code should return #Success to let the save continue. If they do not match, then you have found another document with the same value in the field, so your code should return #Failure with an appropriate error message.
Now here's the caveat: there have been known problems with [RETURNDOCUMENTUNIQUEID] in some versions of Domino, including a bug that caused Domino 6 servers to crash if an agent called ComputeWithForm on a document based on a form that used this feature. There's also a bug that causes it to return only the unid of the first match out of many matches, and so if you have duplicates this strategy in your code will allow users to re-save old documents that are already non-unique instead of forcing them to change them to make them unique, and that may or may not be what you want.
If either of those known issues might create a problem for you, then you would be better off not using [RETURNDOCUMENTUNIQUEID], and instead just do what Notes and Domino programmers did before IBM added the [RETURNDOCUMENTUNIQUEID] option in the first place: add another column to your (lookupUnique) view, and set the column value to #Text(#DocumentUniqueId). Change the 1 in the above #DbLookup formula to the number of the column that you added, and write your validation code to anticipate the possibility that you might get back an empty string, a single value, or a list of values.

Answer 2

If a type 45678 i return a value because there already are a document with that value. I don’t understan how i will validate it.
var dbname = session.getServerName() + "!!" + "proj\\webno.nsf";
getFieldValue = getComponent("oNo").getValue();
tmp = #DbLookup(dbname, "(webNo)", getFieldValue, ”obNo”);
if (tmp == getFieldValue)
{
Here i will do a validate. If value i return are the same as in the getFieldValue
and tmp or just getFieldValue is empty.
}
else
{
Here is it OK
}

Answer 3

Taking your code and modifying it. Assuming we're in the database we're creating the document in, just use #DbName() instead of trying to build the name from the session and some hard-coding. When using validation, the value of the control should be accessible simply with value. Then, just get all the values in the column and see if your value is in there.
I think the following should work.
<xp:inputText id="projectNumber" value="#{doc.ProjectNumber}">
<xp:this.validators>
<xp:validateExpression message="Value already in use">
<xp:this.expression><!CDATA[#{javascript:var usedValues = #DbColumn(#DbName(), "(webNo)", 1);
if ( #IsMember ( value, usedValues ) ) { return false };
return true;
</xp:this.expression>
</xp:validateExpression>
</xp:this.validators>
</xp:inputText>
Why don't you just generate a value for them? The simplest would be to use #Unique, but there are plenty of other ways besides having them have to create one.....