1 files changed, 210 insertions, 0 deletions
diff --git a/lib/handlebars/compiler/whitespace-control.js b/lib/handlebars/compiler/whitespace-control.js
new file mode 100644
index 0000000..e10eb15
--- /dev/null
+++ b/lib/handlebars/compiler/whitespace-control.js
@@ -0,0 +1,210 @@
+import Visitor from "./visitor";
+
+function WhitespaceControl() {
+}
+WhitespaceControl.prototype = new Visitor();
+
+WhitespaceControl.prototype.Program = function(program) {
+  var isRoot = !this.isRootSeen;
+  this.isRootSeen = true;
+
+  var body = program.body;
+  for (var i = 0, l = body.length; i < l; i++) {
+    var current = body[i],
+        strip = this.accept(current);
+
+    if (!strip) {
+      continue;
+    }
+
+    var _isPrevWhitespace = isPrevWhitespace(body, i, isRoot),
+        _isNextWhitespace = isNextWhitespace(body, i, isRoot),
+
+        openStandalone = strip.openStandalone && _isPrevWhitespace,
+        closeStandalone = strip.closeStandalone && _isNextWhitespace,
+        inlineStandalone = strip.inlineStandalone && _isPrevWhitespace && _isNextWhitespace;
+
+    if (strip.close) {
+      omitRight(body, i, true);
+    }
+    if (strip.open) {
+      omitLeft(body, i, true);
+    }
+
+    if (inlineStandalone) {
+      omitRight(body, i);
+
+      if (omitLeft(body, i)) {
+        // If we are on a standalone node, save the indent info for partials
+        if (current.type === 'PartialStatement') {
+          // Pull out the whitespace from the final line
+          current.indent = (/([ \t]+$)/).exec(body[i-1].original)[1];
+        }
+      }
+    }
+    if (openStandalone) {
+      omitRight((current.program || current.inverse).body);
+
+      // Strip out the previous content node if it's whitespace only
+      omitLeft(body, i);
+    }
+    if (closeStandalone) {
+      // Always strip the next node
+      omitRight(body, i);
+
+      omitLeft((current.inverse || current.program).body);
+    }
+  }
+
+  return program;
+};
+WhitespaceControl.prototype.BlockStatement = function(block) {
+  this.accept(block.program);
+  this.accept(block.inverse);
+
+  // Find the inverse program that is involed with whitespace stripping.
+  var program = block.program || block.inverse,
+      inverse = block.program && block.inverse,
+      firstInverse = inverse,
+      lastInverse = inverse;
+
+  if (inverse && inverse.chained) {
+    firstInverse = inverse.body[0].program;
+
+    // Walk the inverse chain to find the last inverse that is actually in the chain.
+    while (lastInverse.chained) {
+      lastInverse = lastInverse.body[lastInverse.body.length-1].program;
+    }
+  }
+
+  var strip = {
+    open: block.openStrip.open,
+    close: block.closeStrip.close,
+
+    // Determine the standalone candiacy. Basically flag our content as being possibly standalone
+    // so our parent can determine if we actually are standalone
+    openStandalone: isNextWhitespace(program.body),
+    closeStandalone: isPrevWhitespace((firstInverse || program).body)
+  };
+
+  if (block.openStrip.close) {
+    omitRight(program.body, null, true);
+  }
+
+  if (inverse) {
+    var inverseStrip = block.inverseStrip;
+
+    if (inverseStrip.open) {
+      omitLeft(program.body, null, true);
+    }
+
+    if (inverseStrip.close) {
+      omitRight(firstInverse.body, null, true);
+    }
+    if (block.closeStrip.open) {
+      omitLeft(lastInverse.body, null, true);
+    }
+
+    // Find standalone else statments
+    if (isPrevWhitespace(program.body)
+        && isNextWhitespace(firstInverse.body)) {
+
+      omitLeft(program.body);
+      omitRight(firstInverse.body);
+    }
+  } else {
+    if (block.closeStrip.open) {
+      omitLeft(program.body, null, true);
+    }
+  }
+
+  return strip;
+};
+
+WhitespaceControl.prototype.MustacheStatement = function(mustache) {
+  return mustache.strip;
+};
+
+WhitespaceControl.prototype.PartialStatement = 
+    WhitespaceControl.prototype.CommentStatement = function(node) {
+  var strip = node.strip || {};
+  return {
+    inlineStandalone: true,
+    open: strip.open,
+    close: strip.close
+  };
+};
+
+
+function isPrevWhitespace(body, i, isRoot) {
+  if (i === undefined) {
+    i = body.length;
+  }
+
+  // Nodes that end with newlines are considered whitespace (but are special
+  // cased for strip operations)
+  var prev = body[i-1],
+      sibling = body[i-2];
+  if (!prev) {
+    return isRoot;
+  }
+
+  if (prev.type === 'ContentStatement') {
+    return (sibling || !isRoot ? (/\r?\n\s*?$/) : (/(^|\r?\n)\s*?$/)).test(prev.original);
+  }
+}
+function isNextWhitespace(body, i, isRoot) {
+  if (i === undefined) {
+    i = -1;
+  }
+
+  var next = body[i+1],
+      sibling = body[i+2];
+  if (!next) {
+    return isRoot;
+  }
+
+  if (next.type === 'ContentStatement') {
+    return (sibling || !isRoot ? (/^\s*?\r?\n/) : (/^\s*?(\r?\n|$)/)).test(next.original);
+  }
+}
+
+// Marks the node to the right of the position as omitted.
+// I.e. {{foo}}' ' will mark the ' ' node as omitted.
+//
+// If i is undefined, then the first child will be marked as such.
+//
+// If mulitple is truthy then all whitespace will be stripped out until non-whitespace
+// content is met.
+function omitRight(body, i, multiple) {
+  var current = body[i == null ? 0 : i + 1];
+  if (!current || current.type !== 'ContentStatement' || (!multiple && current.rightStripped)) {
+    return;
+  }
+
+  var original = current.value;
+  current.value = current.value.replace(multiple ? (/^\s+/) : (/^[ \t]*\r?\n?/), '');
+  current.rightStripped = current.value !== original;
+}
+
+// Marks the node to the left of the position as omitted.
+// I.e. ' '{{foo}} will mark the ' ' node as omitted.
+//
+// If i is undefined then the last child will be marked as such.
+//
+// If mulitple is truthy then all whitespace will be stripped out until non-whitespace
+// content is met.
+function omitLeft(body, i, multiple) {
+  var current = body[i == null ? body.length - 1 : i - 1];
+  if (!current || current.type !== 'ContentStatement' || (!multiple && current.leftStripped)) {
+    return;
+  }
+
+  // We omit the last node if it's whitespace only and not preceeded by a non-content node.
+  var original = current.value;
+  current.value = current.value.replace(multiple ? (/\s+$/) : (/[ \t]+$/), '');
+  current.leftStripped = current.value !== original;
+  return current.leftStripped;
+}
+
+export default WhitespaceControl;