Unexpected boolean behaviour

[fnanfne]

Hi Power People

I have a Gallery displaying a SharePoint List and a TextInput control serving as a search box for this Gallery.

For privacy reasons, only a single item being searched for, should be displayed in the Gallery.

I have attempted to address this requirement by covering the Gallery with an opaque Rectangle. Only when the TextInput search box has more than 3 characters, will the Rectangle disappear, revealing the whole Gallery, which should now only contain a single item. Here is the code on the Rectangle's OnVisible property.

If(Len(TextInput.Text) < 3, true, false)

This works great! Until it unexpectedly doesn't, albeit only briefly. Infrequently, the Rectangle is invisible, even though the TextInput field is empty (<3 characters)

How is this possible?

===================================

A little more background (optional)

If you want, do reference an old post I made trying to find a solution to this requirement here, which I thought I resolved. The simple boolean above also has a Timer control which I omitted for brevity. This is another measure I employed, by delaying when the rectangle disappears.

If(Len(TextInput.Text) < 3, true, 
If(Timer.Value = 0, true, !varDelayOutputTimerUp))

As a final measure, I have added 10 dummy entries into the list, and am sorting this list by Title. So even if the Rectangle is invisible when it shouldn't be, only information that is not sensitive is shown. However, I have seen at least once so far, where I have entered two characters, and the rectangle disappears, again how is this possible?

Another idea I had was to use checks to see how many items is in the list when the search is complete, if more than one item is in the list, the the rectangle will remain visible. Here is the code I thought of using

If(Gallery.AllItemsCount > 1, true false)

I feel like I'm overcomplicating things again.

Any thoughts appreciated!

[Amik]

Hi @fnanfne ,

It might be worth taking a step back and talking about the requirement instead of the solution.

I understand there are privacy concerns and that users should only see a single item based on the entered code. But why use a search function like StartsWith? If users do not know what the unique code is and need to search for it, then logic would indicate that users would need to see different codes in order to identify the right one they need?

If users do know what the code they want to see is, then using a Filter function on the Gallery against the search box (rather than a  StartsWith function) should suffice?  

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[fnanfne]

Hi Amik

Thanks for the reply.

Without going into too much detail, a user might share their screen with external parties while using the app. These external parties should only be able to see their own data, no one else's. All users know the three letter code, if they don't or are unsure, I have placed a convenient button named "Email Items List", which when clicked, will send the user an email with the full list. They can then reference this list from their email client, hopefully on another screen, not seen by the external party, and look for the exact code they want to use. Then return to the App and enter that code.

Here is the code on the Items property of the Gallery

Sort(Filter([@'SharePoint List'], StartsWith(three_letter_code, Upper(TextInput.Text))), Title, SortOrder.Ascending)

Is there another way to address this requirement then? Instead of StartsWith, what can I use?

[developerAJ]

@fnanfne 

you can achieve your requirement by using queryparameter

for this you need to pass values in url ex: powerapplink?screen=screen1&guid=fa0f3d4e-95dc-4352-aab0-c0ed5d0882ae

goto app startscreen property:Switch(Lower( Param("screen")),"screen1",firstScreen,"screen2",SecondScreen);

similarly on respective screen you can use Param("guid") to get the unique value and get the required result for you

you can above reference powerapplink?screen=screen1&code=abc

using the above code Param("code")

Sort(Filter([@'SharePoint List'], StartsWith(three_letter_code, param("code"))), Title, SortOrder.Ascending)

or on screen start store code in a variable

Please click Accept as solution and Thumbs Up. if my post helped you solve your issue. This will help others find it more readily. It also closes the item. If the content was useful in other ways, please consider giving it Thumbs Up.

[Amik]

Thanks for clarifying @fnanfne.

Why does using a Filter function on the Items property of the Gallery not solve this requirement?

Filter(
    'Your Data',
    three_letter_code = TextInput1.Text
)

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[fnanfne]

Hi @developerAJ

This "queryparameter" is new to me, thanks for sharing. I'll play around with that and see if it works for my scenario.

Hey @Amik

I tested but that is not going to address my requirement. Here's some pics to illustrate the problem

This is the screen the user lands on (having navigated here from another screen) Note the amount of items in the Gallery.

I've added some labels (only visible to me) showing how many items are in the gallery, and the status of the variable responsible for initiating a timer control, making the rectangle disappear.

This is what happens when one character is entered into the search box. Note the amount of items now in the Gallery, and the fact that the Rectangle is still visible (covering the Gallery)

Now, a second character is entered in the search box. Again, note the number of items in the Gallery at this point, and also the Rectangle is still visible.

Now, the final character is entered, collapsing the entire List/Gallery into a single item, and also, after a 500ms delay, making the Rectangle invisible, finally exposing the Gallery with the single item shown, ready to be selected.

This all works great, as per the pictures above, however, sometimes, the Rectangle is not visible, when it should be, as per the pic below.

As you can see, this is not the expected behaviour. The search box has zero characters, and so the rectangle should be visible, but it ain't!

How is it possible, that the boolean on the Rectangle is seemingly ignored, albeit only very briefly, and only very sporadically?

Are there some "order of operations" that I am unaware of? Do Booleans load last?

This is what happens when I use your code in the Items property of the Gallery. It shows ALL items in the gallery after one character is entered, not what I want.

I was thinking of changing the Visible property of the Rectangle to include yet another check, like this...

If(Len(TextInput.Text) < 3, true, 
If(Timer.Value = 0, true, 
If(Gallery.AllItemsCount > 1, true, !varDelayOutputTimerUp)))

This again works, but I'm still perplexed as to why I'm seeing this unexpected boolean behaviour.

This should work with only the first check in place (If(Len(TextInput.Text) < 3), true, false) but it doesn't, again, only sometimes.

[developerAJ]

@fnanfne 

Thats strange 

There is a property for textinput control delayoutput but it does not delay by long may be a second it its true.

Anyway if it does not get fixed may be you can use the same formula you are using in gallery.Items. so that your gallery and rectangle will be in sync

just do the countrows(). if its not equal to1 make rectangle visible. so if gallery has more than one item rectangle will appear 

or remove startswith and use =

Sort(Filter([@'SharePoint Items List'], item_code=Upper(TextInput1.Text)), Title, SortOrder.Ascending)

Please click Accept as solution and Thumbs Up. if my post helped you solve your issue. This will help others find it more readily. It also closes the item. If the content was useful in other ways, please consider giving it Thumbs Up.

[fnanfne]

Thank you both!

Although this problem is still up in the air, kind of, I am happy with your suggestions.

I removed the StartsWith, and the code still works as expected, pending further use of course, but this might have caused the issue, let's see.

Further, I have now added the same code to the Items property of the Gallery.

I'll see how this behaves over the next few days and report back.

[Amik · Accepted solution]

Thanks for explanation @fnanfne but I am still not "getting it".

The basic Filter expression I provided above will only display records in the Gallery as long as an absolute match is returned. With this simple solution, there is no need for masking the Gallery with rectangles or anything else.

However, I appreciate there is more to this than I understand, and I hope you find a solution.

Visual example below:

[fnanfne]

I don't know what I did before, but when I tried your code again just now, it works like above!

I have turned the rectangle off and only one result is shown which is just what I want. Looks like this is the best way to scratch the cat, and most efficient. No more boolean checks, and I can also delete the redundant dummy entries. Thanks again to you both, appreciated!