Scanning Field doesn't show existing value when editing

[wangl2]

Dear All,

I built an app using one spreadsheet (in OneDrive) as the data source. 

On this spreadsheet, there is a column called old computer and another column called new computer. Both columns are blank and the idea is to use scanner to bring the information in using the App Scanner. 

The problem I have is: When the information is already in the old computer or new computer label on the App, Edit the whole form will activate the Scanner and ready to scan information in. However, activating the scanner will remove the information already in the label and shows blank. I wanted to existing information remain in the label box even when the scanner is activated.

The scanner is configured to to produce ScanValue1. And the label box is configured to ScanValue1.

1. Scan filed already has value from previous scan

2. Choose Edit to change information for other text box on the form, but these two become blank, even there are data already

3. Scanner button is configured as follow

4. The new computer label is configured as below to receive the scan result

Thank you very much!

[v-siky-msft · Accepted solution]

@wangl2,

Do you use EditForm function or NewForm function to edit the form when activating the scanner?

What is the Items property of the form?  What is the OnSelect property of Edit button? Has the previous scan value been submitted to data source?

I have made a test, please refer to my test steps, edit the view form and replace the text box by scanner value.

1. Set the item property of form: Gallery1.Selected

2. Set the Default property of text box: If (Form1.Mode= FormMode.Edit && Not(IsBlank(scanvalue1)),scanvalue1,Parent.Default)

3. Set the OnScan property of Edit/Scan button: EditForm(Form1);Set(scanvalue1,BarcodeScanner1.Value)

Sik

[wangl2]

@v-siky-msft 

Hi Sik,

I just want to say "Thank you" and how amazing you are! You PowerApps skills is To The Moon! I didn't even expect people could understand my question because I couldn't elaborate well enough.

I have figured it out base on your suggestion! The only thing that confused me a little is that my form in the PowerApps is called "EditForm1" instead of "Form1". So I replaced that using your formula and it works like magic. 

Just to help others to understand the problem and hopefully benefit someone else here, I am listing two different Scan configuration, just to show you my mistake and the right way to configure the Scanner.

So in my form, there are two text labels and two scanner buttons. Each scanner button is configured to feed the scanned value directly to one of the text label.

The wrong way:

Text Label - Property Default: scanValue1

OnScan Value of this scanner button for this label: Set(scanValue1,BarcodeScanner1_1.Value)

Result: When activating the Scanner Button for the first time, it scans and return the value to the Text Label, no problem. The value gets saved and you can view it on the Details form. However, if you hit Edit button to scan again, on the next Edit Form that appears, the previous value in the Text Label disappears, even it is still in the data source. When scanning again, the new value will replace the existing value. I don't like the fact that the previous value is not visible.

The right way:

Text Label - Property Default: If (EditForm1.Mode= FormMode.Edit && Not(IsBlank(scanvalue2)),scanvalue2,Parent.Default)

OnScan Value of this scanner button for this label: EditForm(EditForm1);Set(scanvalue2,BarcodeScanner1.Value)

The Result: When there is already value in the text label, activating the scan button again will still display the existing value in the text label. When scanning again, the new value will just replace the existing value.

Please be sure the EditForm1 is the name of your form, replace as needed. scanvalue1 and scanvalue2 just a variable name, call it whatever you want.

@v-siky-msft Thanks again for your help. I don't exactly understand your formula but it works like a treat. I can see the your text label property is much more complicated than the wrong one I did. Could you please explain a bit more in details?

Thank you all and what a great start of the new year 2020!

Best Regards,

Leo

[wangl2]

Hi @v-siky-msft ,

My App is doing something funny again, but the opposite.

Now when I scan or typed something into the field, save it to the record, and when I open next blank record, the detail page looks fine (with no data in the filed), when I click on edit, the previous scanned data (from the previous record) appears in this new record automatically. If I don't save and leave the edit page, it shows blank again at the detail page. And I can confirm there is no data in this new record from the data source.

I can work around this by quitting the App every time I updated one record. It doesn't behave like this on the Windows Browser. It only does this in the iPad App. This started to happen after I added two more drop-downs to the page. Now the page has 4 drop-down menus.

Is that a bug?

I believe the Scan button has nothing to do with this. It is feeding the data okay. The detail page also seems fine, showing the truth of the data.

Here is how I configured the text field according to your guide.

If (EditForm1.Mode= FormMode.Edit && Not(IsBlank(scanvalue1)),scanvalue1,Parent.Default)

It does to my drop-down field as well. The drop-down value selected for the previous record will show up on the next record (not on Detail page) when you edit. I quit the App and that will disappear.

Please help!

[MasterJ]

Hi, @wangl2  and @v-siky-msft I ran into the same issue, seems like this could be a programming issue, perhaps there is a way to clear the variable after it is scanned which will resolve the problem. Seems to be that when you first use the scan it saves into the scanvalue1 which when scanning a second time passes in that value. Closing and restarting the app is correct since it clears the variable. Hoping for a solution. Please do share if you find out.