Validation Of One Field 'OR' Another Field

[iRadiate]

I have validation on a dropdown char field where the user must make a selection.

Now I need a case where I want to apply validation to 2 dropdown fields where the user must either select one field OR the other but not necessarily both.
Has anyone done this perhaps?

Thanks,
Stephen

[Jay Talbott]

Re: Validation Of One Field 'OR' Another Field

I haven't tried it, but could you make a field with a calculated value that is the concatenation of the two fields that need to be validated, and then require the calculated field to have a value?
Jay

[GGandhi]

Re: Validation Of One Field 'OR' Another Field

assuming you are using a dialog, do you want immediate validation?
this can be tested in the dialogValidate event, I am sure.

edit: actually you can do it in the field immediate validate definition area itself.
go to validation xbasic in the first field uncomment the if end if statement
and add the second field also in evaluation as below, replacing your field names. do the same in the second dropdown. except change the validate_field1 to field2

if e.data.field1 = "" .and. e.data.field2 = "" then
   validate_field1.hasError = .t.
   validate_field1.errorText = "field1 cannot be blank if field2 is also blank."
end if

[iRadiate]

Re: Validation Of One Field 'OR' Another Field

Thanks for the good suggestions guys. Your method seems to work Ghandi. The only odd thing is that only the first field gets highlighted in red.
I added the same code to the second field's xbasic validation and that seems to work highlighting both fields if they are empty.

So this code in the first field only:

function validate_field1 as p (e as p)

if e.data.field1 = "" .and. e.data.field2 = "" then
   validate_field1.hasError = .t. 
   validate_field1.errorText = "At least one Physics or Engineering personel is required."
end if	

end function

Will only highlight field1 in red when validation errors like this:

Multi-Validation.jpg

I also tried this but it doesn't seem to work.

function validate_field1 as p (e as p)

if e.data.field1 = "" .and. e.data.field2 = "" then
   validate_field1.hasError = .t. 
   validate_field2.hasError = .t.
   validate_field1.errorText = "At least one Physics or Engineering personel is required."
end if	

end function

Adding the same code in the second field like this seems to work:

function validate_field2 as p (e as p)

if e.data.field2 = "" .and. e.data.field1 = "" then
   validate_field2.hasError = .t. 
   validate_field2.errorText = "At least one Physics or Engineering personel is required."
end if	

end function

Highlights both fields in red:

Multi-Validation2.jpg

I'm not sure if this is the best way to do it but it seems to be working as expected and not causing any strange behaviour.

Stephen

[GGandhi]

Re: Validation Of One Field 'OR' Another Field

do the same in the second dropdown. except change the validate_field1 to field2

yes you need to do for both fields.
glad to hear it is working out for you, good.

[iRadiate]

Re: Validation Of One Field 'OR' Another Field

yes you need to do for both fields.
glad to hear it is working out for you, good.

Yes, you did say that didn't you. Sometimes I don't listen so well

Thanks

[Davidk]

Re: Validation Of One Field 'OR' Another Field

I feel that this isn't the best way to utilize the tools we've been given... and it kinda breaks the client-side / server-side philosophy.

This is like saying... I want to bake a cake... but I keep my recipe book at the grocery store. I think I may have what I need... but let me go check. So you grab an egg and head out the door passing a friend along the way. Your friend asks where you're going and you ignore them.

You get to the grocery store and check your recipe. It says you need at least one egg. You check your hands... and yup... you have an egg. All happy you head back home. If you continue this scenario... then when you get home you'll ask yourself if you need flour... and by the end of the day you're a very tired baker... and... you're friend is kinda ticked of for being ignored.

What you could have done is let your friend know where you're going. Your friend just happens to be a world renowned expert on cake baking. You'd say... I'm going to the grocery store to see what I need to bake a cake... I think I need at least one egg. Your friend says... yup... you need at least one egg... no need to walk all the way to the store. And... by the way... I can help with the rest of the cake. Everybody's happy.

So... why not let the client side check to see if you've got eggs. And... if not... let you know about it.

Plus... going server-side... if you do have an error... additions are being made the the DOM. So... there's a lot going on... but, in this case, it's not needed.

Here's a simple UX and video to illustrate the concept. The onChange events of the dropdowns need a bit more work so that each dropdown will test for both dropdowns... but this will get you started.

http://www.youtube.com/watch?v=QiJg8omzuS0

[iRadiate]

Re: Validation Of One Field 'OR' Another Field

David,

Wow, thank you so much for that excellent video and explanation. You know, there was something nagging me about the way I was implementing this, but it seemed to work and I didn't know any other way to accomplish the task. This is a great technique, I was unaware of setting class properties like that. It totally makes sense not to be making calls back to the server if you don't have to. I've implemented this method and it works great!

I had to change the css style name from iOS7 to GrBlue to match what I am using in my UX component. With iOS7 the validation worked, preventing a submit, but it didn't turn the field red unless I used GrBlue which is the style I'm using in my UX. I have it set in the onclick event of my submit button, so it ended up like this:

var dd1Ele = {dialog.object}.getPointer('Field1');
var dd2Ele = {dialog.object}.getPointer('Field2');

var dd1 = $gvs(dd1Ele);
var dd2 = $gvs(dd2Ele);

if ( (dd1 == "") && (dd2 == "") ) {

   $acn(dd1Ele,'GrBlueEditError');
   $acn(dd2Ele,'GrBlueEditError');
   $sa(dd1Ele,'title','At least one Field1 or Field2 selection is required.'); 
   $sa(dd2Ele,'title','At least one Field1 or Field2 selection is required.');

} else {

   $rcn(dd1Ele,'GrBlueEditError');
   $rcn(dd2Ele,'GrBlueEditError');
   $sa(dd1Ele,'title','');
   $sa(dd2Ele,'title','');
   
   {dialog.object}.submit();
   
   //Disable the 'SUBMIT' button.
   this.disabled=true;
   //Disable the 'UNDO' button.
   {dialog.object}.setDisabled('BUTTON_RESET');
}

Thank very much for taking the time to pass along this FANTASTIC method.

btw, I'm not a very good baker

Stephen

[Davidk]

Re: Validation Of One Field 'OR' Another Field

Good to hear... glad it worked out. This stuff gets really important when you start to look at mobile. You want to do as much as you can on the client side. Because it's client-side and javascript... it's immediate.

Utilizing the class functions is great... that's just a steal from how Alpha does it. You can go with a pop-up message... or setting text in a static control and then displaying that control. You have many options to get the message out to the user.

[iRadiate]

Re: Validation Of One Field 'OR' Another Field

Hi David,

Just curious, how did you unearth these class methods: $acn, $sa, $rcn ?
I can't seem to find any info on them, at least after searching documentation and wiki.

Thanks,
Stephen

[Davidk]

Re: Validation Of One Field 'OR' Another Field

In the documentation search for Javascript. In the list you'll see 2 entries that start "Alpha Five Javascript Libraries..." The 'core' entry has further links. Selwyn uses these often in his videos and the Javascript Libraries are mentioned throughout the release notes.

$acn and the others are very welcome functions. They are wrappers for existing javascript functionality.

E.g. to add a class using javascript...

var ele = document.getElementById('myDiv');
  if(ele) {
    ele.className += el.className ? ' myNewClass' : 'myNewClass';
  }

This grabs the div using .getElementById and assigns it to ele. If ele exists then... if the element already has a class it appends the new class... otherwise it just adds the class.

.className is the attribute of the ele that you're setting. Same way you'd set .innerHTML.

[iRadiate]

Re: Validation Of One Field 'OR' Another Field

Thank you.