From d57006dd976315aa0222fb3f36e0c857baeb5842 Mon Sep 17 00:00:00 2001
From: Tom MacWright <tom@macwright.org>
Date: Wed, 27 Jun 2012 14:58:56 -0400
Subject: [PATCH] Add advanced field test, fixes for combining fields with
 colors that otherwise go back to mapnik

---
 lib/carto/tree/dimension.js          |  2 +-
 lib/carto/tree/literal.js            |  3 +++
 lib/carto/tree/operation.js          | 16 +++++++++++++++-
 test/rendering/field_advanced.mml    | 23 +++++++++++++++++++++++
 test/rendering/field_advanced.mss    |  6 ++++++
 test/rendering/field_advanced.result | 23 +++++++++++++++++++++++
 6 files changed, 71 insertions(+), 2 deletions(-)
 create mode 100644 test/rendering/field_advanced.mml
 create mode 100644 test/rendering/field_advanced.mss
 create mode 100644 test/rendering/field_advanced.result

diff --git a/lib/carto/tree/dimension.js b/lib/carto/tree/dimension.js
index dfa7de2..0fe8458 100644
--- a/lib/carto/tree/dimension.js
+++ b/lib/carto/tree/dimension.js
@@ -25,7 +25,7 @@ tree.Dimension.prototype = {
         return new tree.Color([this.value, this.value, this.value]);
     },
     toString: function() {
-        return this.value;
+        return this.value.toString();
     },
 
     // In an operation between two Dimensions,
diff --git a/lib/carto/tree/literal.js b/lib/carto/tree/literal.js
index 5281608..135be6c 100644
--- a/lib/carto/tree/literal.js
+++ b/lib/carto/tree/literal.js
@@ -1,3 +1,6 @@
+// A literal is a literal string for Mapnik - the
+// result of the combination of a `tree.Field` with any
+// other type.
 (function(tree) {
 
 tree.Literal = function Field(content) {
diff --git a/lib/carto/tree/operation.js b/lib/carto/tree/operation.js
index 000971e..627063a 100644
--- a/lib/carto/tree/operation.js
+++ b/lib/carto/tree/operation.js
@@ -46,9 +46,23 @@ tree.Operation.prototype.eval = function(env) {
         };
     }
 
+    // Fields, literals, dimensions, and quoted strings can be combined.
     if (a instanceof tree.Field || b instanceof tree.Field ||
         a instanceof tree.Literal || b instanceof tree.Literal) {
-        return new tree.Literal(a.eval(env).toString(true) + this.op + b.eval(env).toString(true));
+        if (a.is === 'color' || b.is === 'color') {
+            env.error({
+               message: "Can't subtract, divide, or multiply colors in expressions.",
+               index: this.index,
+               type: 'runtime',
+               filename: this.filename
+            });
+            return {
+                is: 'undefined',
+                value: 'undefined'
+            };
+        } else {
+            return new tree.Literal(a.eval(env).toString(true) + this.op + b.eval(env).toString(true));
+        }
     }
 
     return a.operate(this.op, b);
diff --git a/test/rendering/field_advanced.mml b/test/rendering/field_advanced.mml
new file mode 100644
index 0000000..12153a4
--- /dev/null
+++ b/test/rendering/field_advanced.mml
@@ -0,0 +1,23 @@
+{
+    "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+    "Stylesheet": [
+        "field_advanced.mss"
+    ],
+    "Layer": [{
+        "name": "world",
+        "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+        "Datasource": {
+            "file": "http://tilemill-data.s3.amazonaws.com/test_data/shape_demo.zip",
+            "type": "shape"
+        }
+    },
+    {
+        "class": "new",
+        "name": "countries",
+        "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+        "Datasource": {
+            "file": "http://tilemill-data.s3.amazonaws.com/test_data/shape_demo.zip",
+            "type": "shape"
+        }
+    }]
+}
diff --git a/test/rendering/field_advanced.mss b/test/rendering/field_advanced.mss
new file mode 100644
index 0000000..68f41e8
--- /dev/null
+++ b/test/rendering/field_advanced.mss
@@ -0,0 +1,6 @@
+#world {
+  text-name: "hello " + [NAME] + " hello" + 2;
+  text-size: 11;
+  text-face-name: "Georgia Regular", "Arial Italic";
+}
+
diff --git a/test/rendering/field_advanced.result b/test/rendering/field_advanced.result
new file mode 100644
index 0000000..cf47ac3
--- /dev/null
+++ b/test/rendering/field_advanced.result
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE Map[]>
+<Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over" maximum-extent="-20037508.34,-20037508.34,20037508.34,20037508.34">
+
+<FontSet name="fontset-0">
+  <Font face-name="Georgia Regular"/>
+  <Font face-name="Arial Italic"/>
+</FontSet>
+<Style name="world" filter-mode="first" >
+  <Rule>
+    <TextSymbolizer size="11" fontset-name="fontset-0" ><![CDATA['hello '+[NAME]+' hello'+2]]></TextSymbolizer>
+  </Rule>
+</Style>
+<Layer name="world"
+  srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
+    <StyleName>world</StyleName>
+    <Datasource>
+       <Parameter name="file"><![CDATA[[absolute path]]]></Parameter>
+       <Parameter name="type"><![CDATA[shape]]></Parameter>
+    </Datasource>
+  </Layer>
+
+</Map>