Migrating from v3.x to v4.0

Update your mods from Geode v3.x to v4.0

Migrating from Geode v3.x to v4.0

Changes to Result

Link to the full docs

Result type has been rewritten from scratch, and it is now shared with many parts of the Geode codebase (Geode itself, TulipHook and matjson).

Method changes

• value() → unwrap()
• expect(str, fmt args...) → Use mapErr along with fmt::format
• Snake case methods renamed to camel case

Universal unwrap macros

GEODE_UNWRAP(res) and GEODE_UNWRAP_INTO(value, res) macros can help a lot when dealing with results:

Result<std::string> addValues(matjson::Value json) {
   // Value::asInt() returns a Result<int>
   GEODE_UNWRAP_INTO(int a, json["a"].asInt());
   GEODE_UNWRAP_INTO(int b, json["b"].asInt());
   // must wrap return value with Ok
   return Ok(fmt::format("sum is {}", a + b));
}

If you only ever expect to build your code with clang, you can use the GEODE_UNWRAP macro like so, for convenience:

Result<int> getInt();

Result<int> foo(int extra) {
    // This will not compile on MSVC
    int value = GEODE_UNWRAP(getInt()) + extra;
    return Ok(value);
}

Changes to the Geode Settings API

Settings v2 has been removed, V3 suffix from classes are now aliased.

Most SettingV3 code should work fine, with the exception of some Result usages:

static Result<std::shared_ptr<MyCustomSettingV3>> parse(std::string const&, std::string const&, matjson::Value const& json) {
   auto res = std::make_shared<MyCustomSettingV3>();
   auto root = checkJson(json, "MyCustomSettingV3");
   // ... some code here ...
   return root.ok(res);
}
// should now be:
//                            ↓ here
static Result<std::shared_ptr<SettingV3>> parse(std::string const&, std::string const&, matjson::Value const& json) {
   auto res = std::make_shared<MyCustomSettingV3>();
   auto root = checkJson(json, "MyCustomSettingV3");
   // ... some code here ...
   //             ↓ here
   return root.ok(std::static_pointer_cast<SettingV3>(res));
}

Changes to utils::MiniFunction

Removed, use std::function now.

Changes to geode::Layout

No longer in cocos2d namespace. Can now be found in Geode/ui/Layout.hpp.

Changes to getChildOfType

Deprecated in 3.9.0, and now removed. Use CCNode::getChildByType<T>(int index) instead:

• getChildOfType<CCLayer>(node, 1) → node->getChildByType<CCLayer>(1)

You can use this regex pattern to quickly find and replace:

• Pattern: getChildOfType<(.+?)>\((.+?),\s*(.+?)\)
• Replace with: $2->getChildByType<$1>($3)

Changes to matjson

Link to the full docs

Result integration

Entire library rewritten to use geode::Result. See result section for tips on how to use Geode’s Result class.

Method naming

Methods are now camel case to fit with rest of Geode’s codebase:

• is_string → isString
• as_string → asString
• etc.

Iteration

matjson::Object has been removed, now you can just iterate directly off a Value (same for arrays!):

matjson::Value someObject = ...;
for (auto& [key, value] : someObject) {
    log::debug("{}: {}", key, value);
}

matjson::Value someArray = ...;
for (auto& value : someArray) {
    log::debug("{}", value);
}

Object creation

Use matjson::makeObject for making objects inline now:

matjson::Value obj = matjson::makeObject({
    { "key", 123 },
    { "another-key": "another value!" }
});

Missing properties

Accessing missing properties with Value::operator[] will now return a null value instead of throwing an exception.

Serialization

Serialization methods have been changed:

• T from_json(matjson::Value const&) → Result<T> fromJson(matjson::Value const&)
  • Make sure to return a Result! Much of the code relies on fromJson returning a Result.
• matjson::Value to_json(T const& value) → matjson::Value toJson(T const& value)
• is_json is no longer used, instead just return an error in fromJson

Other changes

• bool Value::is<T>() removed
• #include <matjson/stl_serialize.hpp> → #include <matjson/std.hpp>
• Added new experimental <matjson/reflect.hpp> header, uses qlibs/reflect to (de)serialize aggregate structs
  • Behavior might change in the future, so use with caution

Changes to JsonChecker / JsonExpectedValue

The JsonChecker class was previously marked deprecated, and is now removed. Now you should move to using JsonExpectedValue instead:

auto checker = JsonChecker(json);
auto root = checker.root("[file.json]").obj();

// ... code

if (checker.isError()) {
    return Err(checker.getError());
}

is now:

auto root = checkJson(json, "[file.json]")

// ... code

GEODE_UNWRAP(root.ok());

JsonChecker::has has different behavior to JsonExpectedValue::has, use JsonExpectedValue::hasNullable to keep old behavior with null values.