Saving Data from a Gallery to SharePoint Using Patch(ForAll()) vs. ForAll(Patch())

When working with Power Apps and SharePoint, you may need to save data from a gallery control to a SharePoint list, often involving both creating new entries and updating existing ones. The way you use the Patch() and ForAll() functions can significantly impact the performance and efficiency of your application. In this article, we will explore why you should prefer using Patch(ForAll()) over ForAll(Patch()), illustrated with examples related to fishing and camping.

Understanding the Functions

Patch()

The Patch() function is used to create or modify records in a data source. It can create new items or update existing ones based on a unique identifier.

ForAll()

The ForAll() function performs a specified action for each item in a collection or table, allowing you to iterate through a list of items to apply changes or save data.

The Difference

• ForAll(Patch()): This approach will iterate through the collection and call Patch() for each item individually, resulting in multiple requests to the SharePoint list, which can slow down performance.
• Patch(ForAll()): This method utilizes ForAll() to gather all items in a single operation. Patch() then applies changes to all items at once, enhancing efficiency.

Example Scenario: Updating and Creating Fishing Trip Data

Let’s consider a scenario where you have a gallery that displays various fishing trip data, including the location, date, the number of fish caught, and a unique identifier for existing trips. You want to update existing records and create new records in a SharePoint list called “FishingTrips.”

Example 1: Using ForAll(Patch()) for Update and Create

ForAll(
    GalleryFishingTrips.AllItems,
    Patch(
        FishingTrips,
        If(
            ThisRecord.ID <> Blank(),
            LookUp(FishingTrips, ID = ThisRecord.ID),  // Update existing record
            Defaults(FishingTrips)  // Create new record
        ),
        {
            Title: ThisRecord.Location,
            Date: ThisRecord.Date,
            FishCaught: ThisRecord.FishCaught
        }
    )
)

In this example, ForAll() iterates over each item in the GalleryFishingTrips. If the ID is present (indicating that it’s an existing trip), it uses LookUp() to find the existing record to update. If the ID is blank, it uses Defaults(FishingTrips) to create a new record. This method leads to multiple requests to SharePoint, which can be inefficient for larger datasets.

Example 2: Using Patch(ForAll()) for Update and Create

Patch(
    FishingTrips,
    ForAll(
        GalleryFishingTrips.AllItems,
        {
            ID: ThisRecord.ID,  // Include ID for updates
            Title: ThisRecord.Location,
            Date: ThisRecord.Date,
            FishCaught: ThisRecord.FishCaught
        }
    )
)

In this improved example, we are using ForAll() to create a collection of records from the GalleryFishingTrips. Each record includes the ID, which indicates whether it’s an update or a new entry. The Patch() function is then used to handle both the creation of new records and the updating of existing ones in a single operation, significantly improving performance.

Why Use Patch(ForAll())?

1. Performance: Reduces the number of requests sent to SharePoint, leading to faster response times.
2. Efficiency: Minimizes server load by consolidating requests, which is essential when dealing with large datasets.
3. Simplified Code: Creates cleaner and easier-to-read code, separating data collection from data saving logic.

Conclusion

When updating and creating data from a gallery to a SharePoint list, using Patch(ForAll()) is the better choice over ForAll(Patch()). This approach not only improves performance and efficiency but also leads to cleaner code. As you develop your applications, consider how data is handled to optimize performance, especially in scenarios with significant data volume, like tracking fishing trips or camping adventures.

Happy coding, and may your apps be as successful as your fishing trips!