tag:capture

README.md

@@ -34,7 +34,7 @@ Documentation: <https://shopify.github.io/liquid/basics/introduction/#tags>
 - [ ] tablerow [Document](https://shopify.github.io/liquid/tags/iteration/) [Source](https://github.com/harttle/shopify-liquid/blob/master/tags/.js) [Test][tt]
 - [ ] tablerow [Document: cols,limit,offset,range](https://shopify.github.io/liquid/tags/iteration/) [Source](https://github.com/harttle/shopify-liquid/blob/master/tags/.js) [Test][tt]
 - [x] assign [Document](https://shopify.github.io/liquid/tags/variable/) [Source](https://github.com/harttle/shopify-liquid/blob/master/tags/assign.js) [Test][tt]
-- [ ] capture [Document](https://shopify.github.io/liquid/tags/variable/) [Source](https://github.com/harttle/shopify-liquid/blob/master/tags/.js) [Test][tt]
+- [x] capture [Document](https://shopify.github.io/liquid/tags/variable/) [Source](https://github.com/harttle/shopify-liquid/blob/master/tags/.js) [Test][tt]
 - [ ] increment [Document](https://shopify.github.io/liquid/tags/variable/) [Source](https://github.com/harttle/shopify-liquid/blob/master/tags/.js) [Test][tt]
 - [ ] decrement [Document](https://shopify.github.io/liquid/tags/variable/) [Source](https://github.com/harttle/shopify-liquid/blob/master/tags/.js) [Test][tt]
 

tags/capture.js

@@ -0,0 +1,18 @@
+var Liquid = require('..');
+var lexical = Liquid.lexical;
+var re = new RegExp(`(${lexical.identifier.source})`);
+
+module.exports = function(liquid) {
+
+    liquid.registerTag('capture', {
+        needClose: true,
+        render: function(tokens, scope, token, hash) {
+            var html = liquid.renderTokens(tokens, scope);
+            var match = token.args.match(re);
+            if (!match) throw new Error(`${token.args} not valid identifier`);
+
+            scope.set(match[1], html);
+        }
+    });
+
+};

test/tags.js

@@ -44,5 +44,12 @@ describe('tags', function() {
         expect(liquid.render('{% unless 1 %}yes{%else%}no{%endunless%}', ctx)).to.equal('no');
         expect(liquid.render('{% unless 1>2 %}yes{%endunless%}', ctx)).to.equal('yes');
     });
+
+    it('should support capture', function(){
+        expect(liquid.render('{% capture f %}{{"a" | capitalize}}{%endcapture%}{{f}}', ctx)).to.equal('A');
+        expect(function(){
+            liquid.render('{% capture = %}{%endcapture%}', ctx);
+        }).to.throw(/= not valid identifier/);
+    });
 });