Recipe 5: In-Game Save/Load Browser UI

This recipe demonstrates how to build a complete, professional Save and Load Game Menu in UMG. It shows how to query save slot metadata in sub-milliseconds without decompressing world data, format timestamps and playtimes, and handle slot creation, loading, and deletion.

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1. Fast Slot Metadata Reads

A common performance pitfall in Unreal save menus is loading every save file into memory just to display the slot names and timestamps in a UI list. With 20 slots of 10 MB each, this causes a multi-second freeze.

How Aegis Solves This

Aegis Save stores all slot metadata in an uncompressed Metadata Section at the very beginning of the .aegis container:

• Get All Slot Info and Get Slot Info read only the first few hundred bytes of each file.
• It never decompresses record bundles.
• A menu with 100 save slots loads in less than 10 milliseconds!

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2. Inspecting FAegisSlotInfo

When querying slots, Aegis returns an array of FAegisSlotInfo:

Field	Type	Description
SlotName	FString	Internal disk identifier (e.g. "SaveSlot_01")
DisplayName	FString	Player-visible name (e.g. "Chapter 3: The Whispering Woods")
TimestampUtc	FDateTime	Real-world date and time when the save was written
PlaytimeSeconds	int32	Total accumulated game time in seconds
RecordCount	int32	Total number of persistent entities in the save
GameSchemaVersion	int32	Developer-defined game patch version
bIsLoadable	bool	Critical: True if this save can be loaded by the current build

Always Check bIsLoadable

If a player tries to load a save written by a future format version or incompatible schema, bIsLoadable will be false. In your UI, gray out the "Load" button or display a compatibility badge!

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3. Blueprint Implementation: Populating the Menu

Step 1: Querying All Slots

In your Save Menu Widget (WBP_SaveGameMenu), bind to Construct or OnMenuOpened:

[Event OnMenuOpened]
       │
       ▼
[Get All Slot Info (Aegis)]
       │
       ▼
[For Each Loop (Array of FAegisSlotInfo)]
       │
       ▼
[Create Widget: WBP_SaveSlotEntry]
  ├── Pass In: FAegisSlotInfo Struct
  └── Add Child to: (ScrollBox_SlotList)

Step 2: Formatting the Entry Widget (WBP_SaveSlotEntry)

Inside the slot entry row widget, bind the text elements:

1. Title: Set to SlotInfo.DisplayName.
2. Date / Time: Convert SlotInfo.TimestampUtc to local time and format as YYYY-MM-DD HH:MM.
3. Playtime: Convert SlotInfo.PlaytimeSeconds into hours, minutes, and seconds:

PlaytimeHours   = Floor(PlaytimeSeconds / 3600)
PlaytimeMinutes = Floor((PlaytimeSeconds % 3600) / 60)
PlaytimeSecs    = PlaytimeSeconds % 60
FormattedText   = Format: "{0}h {1}m {2}s"

4. Load Button: Set Button.SetIsEnabled(SlotInfo.bIsLoadable).

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4. Save, Load, and Delete Actions

Loading a Slot

When the player clicks the "Load Game" button on an entry:

[OnClicked: Button_Load]
       │
       ▼
[Show Loading Screen / Fade Out (0.5s)]
       │
       ▼
[Load Game from Slot (Aegis)]
  ├── Slot Name: SelectedSlotInfo.SlotName
  ├── OnSuccess ──► [Hide Loading Screen / Resume Game]
  └── OnFailed  ──► [Show Dialog: "Failed to load save! " + Status.Context]

Deleting a Slot

When the player clicks the trash icon to delete an old save:

[OnClicked: Button_Delete]
       │
       ▼
[Delete Slot (Aegis)]
  ├── Slot Name: SelectedSlotInfo.SlotName
  └── OnSuccess ──► [Remove Entry Widget from ScrollBox]

Clean Backup Cleanup

Calling Delete Slot cleanly deletes both the .aegis container file and its companion .bak backup file from the player's save directory.

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5. C++ Implementation: Slot Browser Service

For C++ projects, here is a clean helper function to fetch and sort slots:

#include "Core/AegisSubsystem.h"

void UMySaveService::GetSortedSaveSlots(TArray<FAegisSlotInfo>& OutSortedSlots)
{
    OutSortedSlots.Empty();

    UAegisSubsystem* Aegis = UAegisSubsystem::Get(this);
    if (!Aegis)
    {
        return;
    }

    TArray<FAegisSlotInfo> Slots;
    const FAegisStatus Status = Aegis->GetAllSlotInfo(Slots);

    if (Status.IsSuccess())
    {
        // Sort by most recent save timestamp first
        Slots.Sort([](const FAegisSlotInfo& A, const FAegisSlotInfo& B)
        {
            return A.TimestampUtc > B.TimestampUtc;
        });

        OutSortedSlots = MoveTemp(Slots);
    }
}

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Next Steps

• Learn how to optimize saves in massive games in Making Saves Cheap.
• Explore all Blueprint nodes in the Blueprint Node Reference.