Initial commit

lib/assets/javascripts/deep-insights/widgets/auto-style/style-utils.js

@@ -0,0 +1,91 @@
+var _ = require('underscore');
+var postcss = require('postcss');
+var stripInlineComments = require('postcss-strip-inline-comments');
+var SCSSsyntax = require('postcss-scss');
+
+var OUTLINE_ATTRS = ['line-color', 'line-opacity'];
+
+function generateCSSTreeFromCartoCSS (cartocss) {
+  return postcss()
+    .use(stripInlineComments)
+    .process(cartocss, { syntax: SCSSsyntax });
+}
+
+function isPropertyIncluded (cartocss, attr) {
+  var cssTree = generateCSSTreeFromCartoCSS(cartocss);
+  var root = cssTree.result.root;
+  var propertyIncluded = false;
+
+  if (root) {
+    root.walkDecls(attr, function (node) {
+      var parentNode = node.parent;
+
+      if (!isSelectorRule(parentNode) || isMapnikGeometrySelectorRule(parentNode)) {
+        propertyIncluded = true;
+      }
+    });
+  }
+
+  return propertyIncluded;
+}
+
+function isSelectorRule (node) {
+  return node.type === 'rule' && node.selector.search(/\[(.)+\]/g) !== -1;
+}
+
+function isMapnikGeometrySelectorRule (node) {
+  return isSelectorRule(node) && node.selector.search('mapnik::geometry_type') !== -1;
+}
+
+function isOutlineRule (node) {
+  return node.type === 'rule' && node.selector.search('::outline') !== -1;
+}
+
+function replaceWrongSpaceChar (cartocss) {
+  return cartocss.replace(new RegExp(String.fromCharCode(160), 'g'), ' ');
+}
+
+/**
+ * Change attr style and remove all the duplicates
+ * @param  {String} cartocss cartocss original String
+ * @param  {String} attr     CSS Attribute ex, polygon-fill
+ * @param  {String} newStyle New style value ex, red;
+ * @return {String}          Cartocss modified String
+ */
+function changeStyle (cartocss, attr, newStyle) {
+  if (_.isUndefined(newStyle)) return cartocss;
+
+  var cssTree = generateCSSTreeFromCartoCSS(cartocss);
+  var root = cssTree.result.root;
+  var attributeAlreadyChanged = false;
+
+  if (root) {
+    root.walkDecls(attr, function (node) {
+      var parentNode = node.parent;
+
+      if (!(isOutlineRule(parentNode) && _.contains(OUTLINE_ATTRS, attr))) {
+        if (isSelectorRule(parentNode) || attributeAlreadyChanged) {
+          // If the attribute is inside a conditional selection, it has to be removed
+          node.remove();
+        } else {
+          // If the attribute is inside a regular root (or symbolizer), it just
+          // changes the value
+          node.value = newStyle;
+          attributeAlreadyChanged = true;
+        }
+      }
+    });
+
+    return cssTree.css;
+  }
+
+  return cartocss;
+}
+
+module.exports = {
+  changeStyle: _.memoize(changeStyle, function (css, attr, style) {
+    return css + attr + style;
+  }),
+  isPropertyIncluded: isPropertyIncluded,
+  replaceWrongSpaceChar: replaceWrongSpaceChar
+};