Скачать или смотреть PowerApps Power Cards - Card 13 - Displaying your Selection

We use Forms, to display a record. We a have a choice of a Display Form or Edit Form, we are going to use an Edit Form reason being is that you can use an Edit Form to View, Edit and New Data whilst with a Display Form you can only View.
When an Edit form control is in Edit mode, the user can update the record that's specified in the form's Item property. If inspected, the Mode property returns Edit.

When an Edit form control is in New mode, however, the Item property is ignored. The form doesn't show an existing record; instead, the values in each field match the default values of the data source with which you configured the form. The NewForm function causes a form to switch to this mode.

For example, you can set the Text property of a button to show New and its OnSelect property to a formula that includes the NewForm function. If the user selects that button, the form switches to New mode so that the user can create a record starting with known values.

A form switches back to Edit mode if either the ResetForm function runs or the SubmitForm function runs successfully.

You can set the Text property of a button to show Cancel and its OnSelect property to a formula that includes the ResetForm function. If the user selects that button, any changes in progress are discarded, and the values in the form, once again, match the default values of the data source.
You can set the Text property of a button to show Save changes and its OnSelect property to a formula that includes the SubmitForm function. If the user selects that button and the data source is updated, the values in the form are reset to the default values of the data source.
If you create a Save changes button as the previous section describes, the user can create or update a record and then select that button to save those changes to the data source. You could, instead, configure an Image control or some other control to perform the same task, as long as you configure that control with the SubmitForm function. In any case, the Error, ErrorKind, OnSuccess, and OnFailure properties provide feedback on the outcome.

When the SubmitForm function runs, it first validates the data that user wants to submit. If a required field doesn't contain a value or another value doesn't conform to some other constraint, the ErrorKind properties are set, and the OnFailure formula runs. You can configure the Save changes button or other control so that the user can select it only if the data is valid (that is, if the Valid property of the form is true). Note that the user must not only correct the problem but also select the Save changes button again (or discard the changes by selecting a Cancel button, as described earlier) to reset the Error and ErrorKind properties.

If the data passes validation, SubmitForm sends it to the data source, which can take some time depending on network latency.

If the submission succeeds, the Error property is cleared, the ErrorKind property is set to ErrorKind.None, and the OnSuccess formula runs. If the user created a record (that is, if the form was previously in New mode), the form is switched to Edit mode so that the user can edit the newly created record or a different one.
If the submission fails, the Error property contains a user-friendly error message from the data source, explaining the problem. The ErrorKind property is set appropriately, depending on the issue, and the OnFailure formula runs.
Some data sources can detect when two people try to update the same record at the same time In this case, ErrorKind is set to ErrorKind.Conflict, and the remedy is to refresh the data source with the other user's changes and reapply the change made by this user.