@TataLili
DataCards in a form have a Default and an Update property. These are *highly* important to your form and are used to influence many of the features of a form.
The Default property is sort of the "input" to the datacard. It is usually set to ThisItem.yourFIeld So, essentially it is providing the value of the column for the record in the Item property of the form to the datacard. This should very rarely be changed.
The Update property of the datacard is the "output" of the datacard that is supplied to the underlying Updates record...which is what is ultimately written to the datasource during a SubmitForm.
The Unsaved property of the form relies on default and the update properties of all of the datacards in the form. If it senses any difference between the Default and the Update properties of datacards, then the form is considered Unsaved.
Controls all belong to parents. If you add a label to the screen, then the screen is the parent of the label.
If you add a form, the screen is the parent of the form. If you have a datacard in the form, then the form is the parent of the datacard. If you have a control in a datacard, then the datacard is the parent of the control.
SO...since the datacard has a Default and an Update property, then any control in the datacard can access those properties by referencing Parent.<property> In this case, Parent.Default.
So in context now...your Default property of your datacard will have the joined string value of your competitor brand and the Default property will be shown as ThisItem.'Competitor Brand'
The Combobox is in the datacard, so we can reference the Default with Parent.Default - we could have also referenced it with yourDataCardName.Default but, using Parent is much easier.
As a bonus...the keyword Self is also useful. It refers to the control itself. So, for example, the OnSuccess action of the form is where you do actions when a submit is successful. Many times you want to reference the record that was last submitted. Thus, the LastSubmit property is a property that represents the last record written successfully. So, to reference that, you could do yourForm.LastSubmit OR, since you are in the context of the form, Self.LastSubmit is more generic and doesn't stop your train of thought to recall what your form name is.
This goes for any control and any property...you can access it within the context of the control with self.
Like if you have a label and set it to look up a status in a record. Then you have a status, let's say "Open". And now you want the color to be Green if the status is "Open", and Red if it is "Closed". So, in the Color property of the Label, you can have this formula : Switch(Self.Text, "Open", Green, "Closed", Red, Black) This is much quicker that repeating the formula or even having to remember the name of the label.
NOW...the !IsBlank bit.
When you spilt a text string many times that string might have a trailing separator. Don't worry about trying to avoid putting it in because you can just filter it out...
If you have a trailing separator, then you will end up with a last record that is empty because there is nothing beyond the trailing separator. In your scenario with a combobox, this WILL cause the DSI to not work properly (i.e. having a blank record in the DSI table).
So, the purpose of the Filter on the !IsBlank(Result) is just to remove that (or other) empty records from the Split.
Hopefully that is all clear and helpful.
