1 files changed, 42 insertions, 0 deletions
diff --git a/src/mbgl/style/conversion/color_ramp_property_value.cpp b/src/mbgl/style/conversion/color_ramp_property_value.cpp
new file mode 100644
index 0000000000..e792cf3fe4
--- /dev/null
+++ b/src/mbgl/style/conversion/color_ramp_property_value.cpp
@@ -0,0 +1,42 @@
+#include <mbgl/style/conversion/color_ramp_property_value.hpp>
+#include <mbgl/style/conversion.hpp>
+#include <mbgl/style/conversion/constant.hpp>
+#include <mbgl/style/expression/value.hpp>
+#include <mbgl/style/expression/is_constant.hpp>
+#include <mbgl/style/expression/is_expression.hpp>
+#include <mbgl/style/expression/parsing_context.hpp>
+
+namespace mbgl {
+namespace style {
+namespace conversion {
+
+optional<ColorRampPropertyValue> Converter<ColorRampPropertyValue>::operator()(const Convertible& value, Error& error, bool) const {
+    using namespace mbgl::style::expression;
+    if (isUndefined(value)) {
+        return ColorRampPropertyValue();
+    } else if (isExpression(value)) {
+        ParsingContext ctx(type::Color);
+        ParseResult expression = ctx.parseLayerPropertyExpression(value);
+        if (!expression) {
+            error.message = ctx.getCombinedErrors();
+            return nullopt;
+        }
+        assert(*expression);
+        if (!isFeatureConstant(**expression)) {
+            error.message = "data expressions not supported";
+            return nullopt;
+        }
+        if (!isZoomConstant(**expression)) {
+            error.message = "zoom expressions not supported";
+            return nullopt;
+        }
+        return ColorRampPropertyValue(std::move(*expression));
+    } else {
+        error.message = "color ramp must be an expression";
+        return nullopt;
+    }
+}
+
+} // namespace conversion
+} // namespace style
+} // namespace mbgl