--- /dev/null
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2017 Realm Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////
+
+#ifndef REALM_OS_OBJECT_ACCESSOR_IMPL_HPP
+#define REALM_OS_OBJECT_ACCESSOR_IMPL_HPP
+
+#include "object_accessor.hpp"
+
+#include <realm/util/any.hpp>
+
+namespace realm {
+using AnyDict = std::map<std::string, util::Any>;
+using AnyVector = std::vector<util::Any>;
+
+// An object accessor context which can be used to create and access objects
+// using util::Any as the type-erased value type. In addition, this serves as
+// the reference implementation of an accessor context that must be implemented
+// by each binding.
+class CppContext {
+public:
+ // This constructor is the only one used by the object accessor code, and is
+ // used when recurring into a link or array property during object creation
+ // (i.e. prop.type will always be Object or Array).
+ CppContext(CppContext& c, Property const& prop)
+ : realm(c.realm)
+ , object_schema(prop.type == PropertyType::Object ? &*realm->schema().find(prop.object_type) : c.object_schema)
+ { }
+
+ CppContext() = default;
+ CppContext(std::shared_ptr<Realm> realm, const ObjectSchema* os=nullptr)
+ : realm(std::move(realm)), object_schema(os) { }
+
+ // The use of util::Optional for the following two functions is not a hard
+ // requirement; only that it be some type which can be evaluated in a
+ // boolean context to determine if it contains a value, and if it does
+ // contain a value it must be dereferencable to obtain that value.
+
+ // Get the value for a property in an input object, or `util::none` if no
+ // value present. The property is identified both by the name of the
+ // property and its index within the ObjectScehma's persisted_properties
+ // array.
+ util::Optional<util::Any> value_for_property(util::Any& dict,
+ std::string const& prop_name,
+ size_t /* property_index */) const
+ {
+ auto const& v = any_cast<AnyDict&>(dict);
+ auto it = v.find(prop_name);
+ return it == v.end() ? util::none : util::make_optional(it->second);
+ }
+
+ // Get the default value for the given property in the given object schema,
+ // or `util::none` if there is none (which is distinct from the default
+ // being `null`).
+ //
+ // This implementation does not support default values; see the default
+ // value tests for an example of one which does.
+ util::Optional<util::Any>
+ default_value_for_property(ObjectSchema const&, std::string const&) const
+ {
+ return util::none;
+ }
+
+ // Invoke `fn` with each of the values from an enumerable type
+ template<typename Func>
+ void enumerate_list(util::Any& value, Func&& fn) {
+ for (auto&& v : any_cast<AnyVector&>(value))
+ fn(v);
+ }
+
+ // Determine if `value` boxes the same List as `list`
+ bool is_same_list(List const& list, util::Any const& value)
+ {
+ if (auto list2 = any_cast<List>(&value))
+ return list == *list2;
+ return false;
+ }
+
+ // Convert from core types to the boxed type
+ util::Any box(BinaryData v) const { return std::string(v); }
+ util::Any box(List v) const { return v; }
+ util::Any box(Object v) const { return v; }
+ util::Any box(Results v) const { return v; }
+ util::Any box(StringData v) const { return std::string(v); }
+ util::Any box(Timestamp v) const { return v; }
+ util::Any box(bool v) const { return v; }
+ util::Any box(double v) const { return v; }
+ util::Any box(float v) const { return v; }
+ util::Any box(int64_t v) const { return v; }
+ util::Any box(util::Optional<bool> v) const { return v; }
+ util::Any box(util::Optional<double> v) const { return v; }
+ util::Any box(util::Optional<float> v) const { return v; }
+ util::Any box(util::Optional<int64_t> v) const { return v; }
+ util::Any box(RowExpr) const;
+
+ // Any properties are only supported by the Cocoa binding to enable reading
+ // old Realm files that may have used them. Other bindings can safely not
+ // implement this.
+ util::Any box(Mixed) const { REALM_TERMINATE("not supported"); }
+
+ // Convert from the boxed type to core types. This needs to be implemented
+ // for all of the types which `box()` can take, plus `RowExpr` and optional
+ // versions of the numeric types, minus `List` and `Results`.
+ //
+ // `create` and `update` are only applicable to `unbox<RowExpr>`. If
+ // `create` is false then when given something which is not a managed Realm
+ // object `unbox()` should simply return a detached row expr, while if it's
+ // true then `unbox()` should create a new object in the context's Realm
+ // using the provided value. If `update` is true then upsert semantics
+ // should be used for this.
+ template<typename T>
+ T unbox(util::Any& v, bool /*create*/= false, bool /*update*/= false) const { return any_cast<T>(v); }
+
+ bool is_null(util::Any const& v) const noexcept { return !v.has_value(); }
+ util::Any null_value() const noexcept { return {}; }
+ util::Optional<util::Any> no_value() const noexcept { return {}; }
+
+ // KVO hooks which will be called before and after modying a property from
+ // within Object::create().
+ void will_change(Object const&, Property const&) {}
+ void did_change() {}
+
+ // Get a string representation of the given value for use in error messages.
+ std::string print(util::Any const&) const { return "not implemented"; }
+
+ // Cocoa allows supplying fewer values than there are properties when
+ // creating objects using an array of values. Other bindings should not
+ // mimick this behavior so just return false here.
+ bool allow_missing(util::Any const&) const { return false; }
+
+private:
+ std::shared_ptr<Realm> realm;
+ const ObjectSchema* object_schema = nullptr;
+
+};
+
+inline util::Any CppContext::box(RowExpr row) const
+{
+ REALM_ASSERT(object_schema);
+ return Object(realm, *object_schema, row);
+}
+
+template<>
+inline StringData CppContext::unbox(util::Any& v, bool, bool) const
+{
+ if (!v.has_value())
+ return StringData();
+ auto& value = any_cast<std::string&>(v);
+ return StringData(value.c_str(), value.size());
+}
+
+template<>
+inline BinaryData CppContext::unbox(util::Any& v, bool, bool) const
+{
+ if (!v.has_value())
+ return BinaryData();
+ auto& value = any_cast<std::string&>(v);
+ return BinaryData(value.c_str(), value.size());
+}
+
+template<>
+inline RowExpr CppContext::unbox(util::Any& v, bool create, bool update) const
+{
+ if (auto object = any_cast<Object>(&v))
+ return object->row();
+ if (auto row = any_cast<RowExpr>(&v))
+ return *row;
+ if (!create)
+ return RowExpr();
+
+ REALM_ASSERT(object_schema);
+ return Object::create(const_cast<CppContext&>(*this), realm, *object_schema, v, update).row();
+}
+
+template<>
+inline util::Optional<bool> CppContext::unbox(util::Any& v, bool, bool) const
+{
+ return v.has_value() ? util::make_optional(unbox<bool>(v)) : util::none;
+}
+
+template<>
+inline util::Optional<int64_t> CppContext::unbox(util::Any& v, bool, bool) const
+{
+ return v.has_value() ? util::make_optional(unbox<int64_t>(v)) : util::none;
+}
+
+template<>
+inline util::Optional<double> CppContext::unbox(util::Any& v, bool, bool) const
+{
+ return v.has_value() ? util::make_optional(unbox<double>(v)) : util::none;
+}
+
+template<>
+inline util::Optional<float> CppContext::unbox(util::Any& v, bool, bool) const
+{
+ return v.has_value() ? util::make_optional(unbox<float>(v)) : util::none;
+}
+
+template<>
+inline Mixed CppContext::unbox(util::Any&, bool, bool) const
+{
+ throw std::logic_error("'Any' type is unsupported");
+}
+}
+
+#endif // REALM_OS_OBJECT_ACCESSOR_IMPL_HPP
fnp / wl-app.git / blobdiff