From 3ffdcc9639764f41d0a87a0f1fd6810feb05ba46 Mon Sep 17 00:00:00 2001
From: orangemug <info@orangemug.co.uk>
Date: Mon, 17 Feb 2020 11:52:40 +0000
Subject: [PATCH] Added the ability to convert from data/zoom function to
 expression

---
 src/components/fields/FunctionSpecField.jsx | 13 ++++++++++++-
 src/components/fields/_DataProperty.jsx     |  6 ++++++
 src/components/fields/_ZoomProperty.jsx     |  6 ++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/components/fields/FunctionSpecField.jsx b/src/components/fields/FunctionSpecField.jsx
index fb12a45b..e5a45375 100644
--- a/src/components/fields/FunctionSpecField.jsx
+++ b/src/components/fields/FunctionSpecField.jsx
@@ -5,6 +5,7 @@ import SpecProperty from './_SpecProperty'
 import DataProperty from './_DataProperty'
 import ZoomProperty from './_ZoomProperty'
 import ExpressionProperty from './_ExpressionProperty'
+import {function as styleFunction} from '@mapbox/mapbox-gl-style-spec';
 
 
 function isLiteralExpression (value) {
@@ -218,7 +219,15 @@ export default class FunctionSpecProperty  extends React.Component {
   }
 
   makeExpression = () => {
-    const expression = ["literal", this.props.value || this.props.fieldSpec.default];
+    const {value, fieldSpec} = this.props;
+    let expression;
+
+    if (typeof(value) === "object" && 'stops' in value) {
+      expression = styleFunction.convertFunction(value, fieldSpec);
+    }
+    else {
+      expression = ["literal", value || this.props.fieldSpec.default];
+    }
     this.props.onChange(this.props.fieldName, expression);
   }
 
@@ -277,6 +286,7 @@ export default class FunctionSpecProperty  extends React.Component {
           value={this.props.value}
           onDeleteStop={this.deleteStop}
           onAddStop={this.addStop}
+          onExpressionClick={this.makeExpression} 
         />
       )
     }
@@ -291,6 +301,7 @@ export default class FunctionSpecProperty  extends React.Component {
           value={this.props.value}
           onDeleteStop={this.deleteStop}
           onAddStop={this.addStop}
+          onExpressionClick={this.makeExpression} 
         />
       )
     }
diff --git a/src/components/fields/_DataProperty.jsx b/src/components/fields/_DataProperty.jsx
index f3cef010..7503d62c 100644
--- a/src/components/fields/_DataProperty.jsx
+++ b/src/components/fields/_DataProperty.jsx
@@ -269,6 +269,12 @@ export default class DataProperty extends React.Component {
       >
         Add stop
       </Button>
+      <Button
+        className="maputnik-add-stop"
+        onClick={this.props.onExpressionClick.bind(this)}
+      >
+        Convert to expression
+      </Button>
     </div>
   }
 }
diff --git a/src/components/fields/_ZoomProperty.jsx b/src/components/fields/_ZoomProperty.jsx
index 21bb7f7b..3db421f2 100644
--- a/src/components/fields/_ZoomProperty.jsx
+++ b/src/components/fields/_ZoomProperty.jsx
@@ -177,6 +177,12 @@ export default class ZoomProperty extends React.Component {
       >
         Add stop
       </Button>
+      <Button
+        className="maputnik-add-stop"
+        onClick={this.props.onExpressionClick.bind(this)}
+      >
+        Convert to expression
+      </Button>
     </div>
   }
 }