Clear and ClearCollect Functions in PowerApps: A Comprehensive Guide
1. Introduction to Clear and ClearCollect Functions in PowerApps
In PowerApps, collections are powerful tools used to temporarily store data. However, managing this data efficiently requires more than just collecting it. This is where Clear and ClearCollect functions in PowerApps come into play. These two functions are essential for creating, resetting, and managing collections during the lifecycle of an app.
In this article, we’ll explore how Clear and ClearCollect functions in PowerApps can help you structure data dynamically, enhance performance, and build intuitive user interfaces.
Table of Contents – Clear and ClearCollect Functions in PowerApps
- Introduction to Clear and ClearCollect Functions in PowerApps
- Understanding Collections in PowerApps
- What is the Clear Function in PowerApps?
- What is the ClearCollect Function in PowerApps?
- Syntax and Parameters
- Key Differences Between Clear and ClearCollect
- Creating and Initializing Collections
- Using Clear Function to Remove All Records
- Using ClearCollect to Refresh Collections
- Collect vs ClearCollect vs Clear
- Using Clear and ClearCollect with Galleries
- Form Reset and Temporary Data Storage
- Dynamic Filtering with ClearCollect
- ClearCollect with SharePoint, Excel, and Dataverse
- Delegation Considerations with ClearCollect
- Common Use Cases of Clear and ClearCollect Functions
- Common Mistakes and How to Avoid Them
- Best Practices for Using Clear and ClearCollect Functions in PowerApps
- Performance Considerations
- Conclusion: Mastering Clear and ClearCollect in PowerApps
2. Understanding Collections in PowerApps
Before diving into the Clear and ClearCollect functions, it’s crucial to understand what a collection is. A collection in PowerApps is a local, temporary in-memory table used to store data while the app is running.
Collections are often used to:
- Store user inputs before submitting
- Build shopping carts or dashboards
- Manage offline data
- Work with filtered or transformed datasets
Collections are not saved permanently unless explicitly stored using SaveData().
3. What is the Clear Function in PowerApps?
The Clear() function is used to remove all records from a collection or data source, essentially resetting it. It does not delete the collection structure, only its contents.
Syntax
Clear(CollectionName)
Example
Clear(colTasks)
This command clears all tasks from the colTasks collection.
4. What is the ClearCollect Function in PowerApps?
The ClearCollect() function is a combination of two actions:
- Clears the existing records
- Collects new data into the same collection
This function is highly efficient when you want to refresh a collection with new data.
Syntax
ClearCollect(CollectionName, DataSource)
Example
ClearCollect(colEmployees, Employees)
This refreshes the colEmployees collection with the latest records from the Employees data source.
5. Syntax and Parameters
Clear
Clear(Collection)
- Collection: The name of the collection to clear
ClearCollect
ClearCollect(Collection, Data)
- Collection: The collection to clear and repopulate
- Data: New data to insert
These concise syntaxes make Clear and ClearCollect functions in PowerApps simple yet powerful.
6. Key Differences Between Clear and ClearCollect
| Feature | Clear() |
ClearCollect() |
|---|---|---|
| Clears data | ✅ | ✅ |
| Adds new data | ❌ | ✅ |
| Common usage | Resetting collections | Refreshing collections |
| Delegable | ✅ (for collections) | ✅ (partially, based on data source) |
Understanding when to use each is vital in mastering Clear and ClearCollect functions in PowerApps.
7. Creating and Initializing Collections
To create and initialize collections, use ClearCollect() inside the App.OnStart property or screen OnVisible.
Example
ClearCollect(colProjects, Projects)
This will create and fill the colProjects collection with data from the Projects data source.
8. Using Clear Function to Remove All Records
When a form is submitted or reset, you may want to remove all previous entries.
Example
Clear(colFormInputs)
This is especially useful for resetting forms, clearing shopping carts, or initializing screen loads with empty states using Clear and ClearCollect functions in PowerApps.
9. Using ClearCollect to Refresh Collections
Instead of first clearing a collection and then using Collect(), you can use ClearCollect() to do both in one step.
Example
ClearCollect(colFilteredTasks, Filter(Tasks, Priority = "High"))
Here, the colFilteredTasks collection is updated with only high-priority tasks.
10. Collect vs ClearCollect vs Clear
| Function | Use Case |
|---|---|
Collect() |
Add new records without removing existing ones |
Clear() |
Remove all records |
ClearCollect() |
Replace existing records with new data |
These three work best when used together in structured workflows, especially in apps relying on Clear and ClearCollect functions in PowerApps.
11. Using Clear and ClearCollect with Galleries
Gallery Items Example
Gallery.Items = colTasks
Update Data with Button
ClearCollect(colTasks, Filter(Tasks, AssignedTo = User().FullName))
This refreshes the gallery each time the button is clicked, improving interactivity using Clear and ClearCollect functions in PowerApps.
12. Form Reset and Temporary Data Storage
Forms often use local collections for multi-step input or data caching. Reset them using Clear().
Example
Clear(colFormCache)
ResetForm(frmCustomer)
Clear out temporary form data and reset UI elements simultaneously.
13. Dynamic Filtering with ClearCollect
Use ClearCollect() to dynamically filter and cache data based on user selections.
Example
ClearCollect(colFilteredOrders, Filter(Orders, Status = ddStatus.Selected.Value))
Dynamic interfaces benefit greatly from Clear and ClearCollect functions in PowerApps for real-time updates.
14. ClearCollect with SharePoint, Excel, and Dataverse
SharePoint
ClearCollect(colLeaveRequests, Filter(LeaveRequests, Status = "Pending"))
Excel
ClearCollect(colInventory, ExcelTable)
Dataverse
ClearCollect(colAccounts, Filter(Accounts, 'Revenue' > 100000))
Clear and ClearCollect allow fast, flexible data binding with these connectors.
15. Delegation Considerations with ClearCollect
Clear and ClearCollect are delegable only to the extent of the data retrieval, not for client-side operations.
If your filtered dataset exceeds the delegation limit (500 or 2000 rows), you will need pagination or data virtualization.
Delegation Tip
ClearCollect(colEmployees, Filter(Employees, StartsWith(Name, "A")))
Ensure filters are delegable when using Clear and ClearCollect functions in PowerApps to avoid performance issues.
16. Common Use Cases of Clear and ClearCollect Functions
- Shopping carts: Reset and refresh items
- Dashboards: Update KPIs or visual data dynamically
- Surveys: Clear previous answers before starting
- Reports: Filtered result sets displayed in galleries
- Multi-step forms: Clear previous entries on navigation
These real-world use cases illustrate the value of Clear and ClearCollect functions in PowerApps.
17. Common Mistakes and How to Avoid Them
| Mistake | Solution |
|---|---|
Using Clear() on non-existent collections |
Always initialize the collection first |
Expecting Clear() to delete structure |
It only removes records |
Overwriting data unintentionally with ClearCollect() |
Validate user filters before refresh |
| Hitting delegation limits | Use delegable filters with data sources |
18. Best Practices for Using Clear and ClearCollect Functions in PowerApps
✅ Use ClearCollect() when refreshing data
✅ Use Clear() before collecting from forms
✅ Always validate inputs before calling ClearCollect()
✅ Initialize collections in App.OnStart
✅ Name collections consistently (e.g., colOrders, colTempData)
✅ Keep collection size manageable for performance
These best practices ensure your app remains maintainable, responsive, and scalable.
19. Performance Considerations
- Collections are stored in memory — use them efficiently.
- Prefer server-side filtering before
ClearCollect(). - Avoid large, unnecessary
Clear()calls. - Minimize repeated
ClearCollect()on static data.
20. Conclusion: Mastering Clear and ClearCollect in PowerApps
In summary, Clear and ClearCollect functions in PowerApps are foundational tools that every app maker should master. They enable dynamic data handling, refreshing views, resetting forms, and filtering datasets—all while keeping the app fast and responsive.
Key Takeaways:
Clear()removes all records from a collectionClearCollect()refreshes collections with new data- Use both functions to manage temporary storage effectively
- Combine with galleries, forms, and filters for powerful experiences
- Understand delegation to prevent unexpected results
Here’s a comprehensive overview of PowerApps functions, organized for easy understanding and reference. You can also check the reference here