Page Comparison

In this chapter, we 'll will update the app to have a more natural screen flow. This involves hiding buttons that are not needed when the user is doing certain things:

...

Go into App Mode and try the new button. You will see that it clears the values from all fields on the form. Therefore, this is a useful button to press before entering details for a new contact.

• Update the button label to New

Now we will hide a button that users do not need to see when they are entering details for a new contact. We will hide the Update button when the details on the screen are blank. To do this, we can test the value of UID. Remember that the UID field is configured on the edit screen, and hidden - but this means we can use the value of UID. We know that UID is always set for every record, so we can test whether this is null or not to work out whether the fields on the edit form are currently populated. Remember also that to access a value on the edit form in an expression we can use _form.

To hide the Update button:

• Click on the Update button to open the configuration details
• Go to the section Formatting Rules
• Add a formatting rule
• Set the Rule Expression to _form.UID==_NULL
• Since there is currently no hidden style, add one:
  • Next to Style, press Image Added - Add Style
  • Set Name to Hidden
  • Click the Hidden flag
  • Save the new style
• In the formatting rule, set the Style to Hidden
• Save the formatting rule

Now update the Add button so that it is not shown when the user is updating a record, that is, when the UID field is set:

• Open configuration details for the Add button
• Add a formatting rule
• Set the Rule Expression to _form.UID!=_NULL
• set the Style to Hidden
• Save the formatting rule

Go into App Mode, and check that when you press New, all fields are cleared and the Update button disappears, but the Add button is shown. Also check that when you select a record, the Add button disappears but the Update button is shown.