1 files changed, 83 insertions, 0 deletions
diff --git a/bin/lib/less/tree/import.js b/bin/lib/less/tree/import.js
new file mode 100644
index 00000000..7a977def
--- /dev/null
+++ b/bin/lib/less/tree/import.js
@@ -0,0 +1,83 @@
+(function (tree) {
+//
+// CSS @import node
+//
+// The general strategy here is that we don't want to wait
+// for the parsing to be completed, before we start importing
+// the file. That's because in the context of a browser,
+// most of the time will be spent waiting for the server to respond.
+//
+// On creation, we push the import path to our import queue, though
+// `import,push`, we also pass it a callback, which it'll call once
+// the file has been fetched, and parsed.
+//
+tree.Import = function (path, imports, features, once, index) {
+    var that = this;
+
+    this.once = once;
+    this.index = index;
+    this._path = path;
+    this.features = features && new(tree.Value)(features);
+
+    // The '.less' extension is optional
+    if (path instanceof tree.Quoted) {
+        this.path = /\.(le?|c)ss(\?.*)?$/.test(path.value) ? path.value : path.value + '.less';
+    } else {
+        this.path = path.value.value || path.value;
+    }
+
+    this.css = /css(\?.*)?$/.test(this.path);
+
+    // Only pre-compile .less files
+    if (! this.css) {
+        imports.push(this.path, function (e, root, imported) {
+            if (e) { e.index = index }
+            if (imported && that.once) that.skip = imported;
+            that.root = root || new(tree.Ruleset)([], []);
+        });
+    }
+};
+
+//
+// The actual import node doesn't return anything, when converted to CSS.
+// The reason is that it's used at the evaluation stage, so that the rules
+// it imports can be treated like any other rules.
+//
+// In `eval`, we make sure all Import nodes get evaluated, recursively, so
+// we end up with a flat structure, which can easily be imported in the parent
+// ruleset.
+//
+tree.Import.prototype = {
+    toCSS: function (env) {
+        var features = this.features ? ' ' + this.features.toCSS(env) : '';
+
+        if (this.css) {
+            return "@import " + this._path.toCSS() + features + ';\n';
+        } else {
+            return "";
+        }
+    },
+    eval: function (env) {
+        var ruleset, features = this.features && this.features.eval(env);
+
+        if (this.skip) return [];
+
+        if (this.css) {
+            return this;
+        } else {
+            ruleset = new(tree.Ruleset)([], this.root.rules.slice(0));
+
+            for (var i = 0; i < ruleset.rules.length; i++) {
+                if (ruleset.rules[i] instanceof tree.Import) {
+                    Array.prototype
+                         .splice
+                         .apply(ruleset.rules,
+                                [i, 1].concat(ruleset.rules[i].eval(env)));
+                }
+            }
+            return this.features ? new(tree.Media)(ruleset.rules, this.features.value) : ruleset.rules;
+        }
+    }
+};
+
+})(require('../tree'));