Gallery when loading shows old items before new items show up

[Anonymous]

Hi All,

I have setup a power app connected to sharepoint.

I have 2 button - Screen 1

One gallery - Screen 2

Button has a variable when clicked, that variable is used in the Filter query to populate gallery. Clicking on the button 1 takes me to screen2 and populates the gallery based on button 1 variable.

Issue is, when i come back to screen 1 and click on button 2, it takes me to screen 2 and shows the gallery items for button 1 for few seconds before populating the gallery with Button 2  variable data.

Is there a way i can stop showing old data in gallery when new data is being loaded. Basically looking like resetting the gallery. There is a reset option but i did not find any change when using it.

any help is appreciated

[CNT]

@Anonymous What is ThisItem referring to?

[Anonymous]

Its referring the current item ID. ID column from sharepoint

[CNT]

@Anonymous Are these buttons inside a Gallery?

[Anonymous]

@CNT  yes

[CNT]

@Anonymous If so, Button 1 & Button 2 are doing exactly the same thing. Not quite sure what you are trying to achieve. Please share a screen shot.

[Anonymous]

@CNT 

I have 2 items in the Gallery. Clicking on Edit takes me to another screen which has the gallery. Edit has the set variable which is 32 .

The gallery in screen 2 filters record for 32.

When i come back to this screen and edit 33 it takes me to screen 2 but briefly shows 32 items before gallery refreshes to show 33 items

Hope this helps

[RandyHayes · Accepted solution]

@Anonymous 

Your going to see this type of action with a lot of controls as they have to gather any data needed when they render.

My suggestion would be to avoid doing the Filter in the Gallery...do the filter in the button.

Example: 

   Button1 OnSelect

    Set(glbGalleryList, Filter(yourDataSource, <criteria>));

    Navigate(Screen2)

   Button2 OnSelect

    Set(glbGalleryList, Filter(yourDataSource, <othercriteria>));

    Navigate(Screen2)

Next, set the Items property of the Gallery on screen 2 to glbGalleryList

Make sure you are NOT switching datasources on the gallery...it needs a consistent schema.

PowerApps will "wait" at the set line of your formula for the variable to be populated...so, your Gallery will have its data already in the variable when you arrive at screen2 rather than, when you arrive at screen2, that the Gallery begins to get the data.

I hope this is helpful for you.

[Anonymous]

wow @RandyHayes , never though i could use filter within set. Is there any limitations of doing this

[RandyHayes]

@Anonymous 

Not at all - no limitations except available memory.  Variables are any type you want them to be.  They can be simple or complex.

In contrast, many people use collections just like this.  But, unless you need the ability to add, remove, or update records in an in-memory database, the collection is overkill.

Essentially, you are creating a snapshot of a table (just like a collection does).  Your Gallery wants a table for Items...that variable can be it.

This is also a method to keep in mind for bringing in any static datasource into your app.  For example, if you had a list of countries in a datasource and you wanted to use it in your app without going to the datasource (cloud session) over and over, you could do a Set(glbCountries, yourCountryDataList) in the OnStart of the app and then you will have that list in your app available throughout.  I used countries as an example, because it would be a relatively static/unchanging data list.

[Anonymous]

@RandyHayes , this is so helpful. Thanks you so much for all the information and your solution works as i wanted. Thanks for your support