liquid instance

filter.js

@@ -1,46 +1,48 @@
 const lexical = require('./lexical.js');
 const _ = require('lodash');
 
-var filters = {};
-
 var _filterInstance = {
     render: function(output, ctx) {
         var args = this.args.map(arg => ctx.get(arg));
         args.unshift(output);
         return this.filter.apply(null, args);
     }
-}
+};
 
-function parse(str) {
-    var match = lexical.patterns.filterLine.exec(str.trim());
-    if (!match) {
-        throw new Error('illegal filter: ' + str);
+module.exports = function() {
+    var filters = {};
+
+    function parse(str) {
+        var match = lexical.patterns.filterLine.exec(str.trim());
+        if (!match) {
+            throw new Error('illegal filter: ' + str);
+        }
+        var k = match[1],
+            v = match[2];
+
+        return factory(k, [v]);
     }
-    var k = match[1],
-        v = match[2];
 
-    return factory(k, [v]);
-}
+    function factory(name, args) {
+        var filter = filters[name];
+        if (typeof filter !== 'function')
+            throw new Error(`filter ${name} not found`);
 
-function factory(name, args) {
-    var filter = filters[name];
-    if (typeof filter !== 'function') 
-        throw new Error(`filter ${name} not found`);
+        var instance = Object.create(_filterInstance);
+        instance.args = args;
+        instance.filter = filter;
+        return instance;
+    }
 
-    var instance = Object.create(_filterInstance);
-    instance.args = args;
-    instance.filter = filter;
-    return instance;
-}
+    function register(name, filter) {
+        filters[name] = filter;
+    }
 
-function register(name, filter) {
-    filters[name] = filter;
-}
+    function clear() {
+        filters = {};
+    }
 
-function clear() {
-    filters = {};
-}
-
-exports.parse = parse;
-exports.register = register;
-exports.clear = clear;
+    return {
+        parse, register, clear
+    };
+};

filters/abs.js

@@ -0,0 +1 @@
+module.exports =  v => Math.abs(v);

index.js

@@ -2,9 +2,45 @@ const context = require('./context');
 const tokenizer = require('./tokenizer.js');
 const render = require('./render.js');
 const lexical = require('./lexical.js');
+const path = require("path");
+const fs = require('fs');
+const Tag = require('./tag.js');
+const Filter = require('./filter.js');
 
-exports.render = function(html, ctx){
-    return render(tokenizer(html), context.factory(ctx));
+const tagsPath = path.join(__dirname, "tags");
+const filtersPath = path.join(__dirname, "filters");
+
+var _engine = {
+    render: function(html, ctx) {
+        return this.doRender(tokenizer.parse(html), context.factory(ctx));
+    },
+    lexical,
+    registerFilter : function(name, filter){
+        return this.filter.register(name, filter);
+    },
+    registerTag : function(name, tag){
+        return this.filter.register(name, tag);
+    } 
 };
 
-exports.lexical = lexical;
+function factory(){
+    var engine = Object.create(_engine);
+    engine.tag = Tag();
+    engine.filter = Filter();
+    engine.doRender = render(engine.filter, engine.tag);
+
+    fs.readdirSync(tagsPath).map(function(f){
+        var match = /^(\w+)\.js$/.exec(f);
+        if(!match) return;
+        engine.tag.register(match[1], require("./tags/" + f));
+    });
+
+    fs.readdirSync(filtersPath).map(function(f){
+        var match = /^(\w+)\.js$/.exec(f);
+        if(!match) return;
+        engine.filter.register(match[1], require("./filters/" + f));
+    });
+    return engine;
+}
+
+module.exports = factory;

lexical.js

@@ -3,7 +3,7 @@ const _ = require('lodash');
 var singleQuoted = /'[^']*'/;
 var doubleQuoted = /"[^"]*"/;
 
-var number = /\d+\.?\d*|\.?\d+/;
+var number = /-?\d+\.?\d*|\.?\d+/;
 var bool = /true|false/i;
 var range = /\((\d+)\.\.(\d+)\)/;
 var identifier = /[a-zA-Z_$][a-zA-Z_$0-9]*/;

render.js

@@ -1,46 +1,44 @@
-const Filter = require('./filter');
-const Tag = require('./tag');
-
-module.exports = function render(tokens, ctx) {
-    var html = '';
-    for (var i = 0; i < tokens.length; i++) {
-        var token = tokens.shift();
-        switch (token.type) {
-            case 'html':
-                html += token.value;
-                break;
-            case 'output':
-                html += renderOutput(token);
-                break;
-            case 'tag':
-                html += renderTag(token);
-                break;
-            default:
-                throw new Error(`unexpected type: ${token.type}`);
-        }
-    }
-    return html;
-
-    function renderOutput(token) {
-        var filters = token.value.split('|');
-        var val = ctx.get(filters.shift());
-        return filters
-            .map(str => Filter.parse(str))
-            .reduce((v, filter) => filter.render(v, ctx), val);
-    }
-
-    function renderTag(token) {
-        var tag = Tag.parse(token.value), subTokens = [];
-        if(tag.needClose){
-            var curToken, endToken = 'end' + tag.name;
-            while((curToken = tokens.shift()).value !== endToken){
-                subTokens.push(curToken);
-            }
-            if(curToken.value !== endToken){
-                throw new Error(`${token.value} not closed`);
+module.exports = (Filter, Tag) =>
+    function render(tokens, ctx) {
+        var html = '';
+        for (var i = 0; i < tokens.length; i++) {
+            var token = tokens.shift();
+            switch (token.type) {
+                case 'html':
+                    html += token.value;
+                    break;
+                case 'output':
+                    html += renderOutput(token);
+                    break;
+                case 'tag':
+                    html += renderTag(token);
+                    break;
+                default:
+                    throw new Error(`unexpected type: ${token.type}`);
             }
         }
-        return tag.render(subTokens, ctx);
-    }
-};
+        return html;
 
+        function renderOutput(token) {
+            var filters = token.value.split('|');
+            var val = ctx.get(filters.shift());
+            return filters
+                .map(str => Filter.parse(str))
+                .reduce((v, filter) => filter.render(v, ctx), val);
+        }
+
+        function renderTag(token) {
+            var tag = Tag.parse(token.value),
+                subTokens = [];
+            if (tag.needClose) {
+                var curToken, endToken = 'end' + tag.name;
+                while ((curToken = tokens.shift()).value !== endToken) {
+                    subTokens.push(curToken);
+                }
+                if (curToken.value !== endToken) {
+                    throw new Error(`${token.value} not closed`);
+                }
+            }
+            return tag.render(subTokens, ctx);
+        }
+    };

tag.js

@@ -1,57 +1,58 @@
 const lexical = require('./lexical.js');
-const context = require('./context.js');
-
-var tags = {};
 
 var _tagInstance = {
-    render: function(tokens, ctx){
+    render: function(tokens, ctx) {
         var obj = hash(this.markup, ctx);
         return this.tag.render(tokens, ctx, this.markup, obj);
     }
 };
 
-function register(name, tag){
-    if(typeof tag.render !== 'function'){
-        throw new Error(`expect ${name}.render to be a function`);
-    }
-    tags[name] = tag;
-}
-
-function parse(str){
-    var match = lexical.patterns.identifier.exec(str.trim());
-    if(!match) throw new Error('illegal tag: '+ str);
-
-    var tagInstance = factory(match[0], str);
-    return tagInstance;
-}
-
-function hash(markup, ctx){
+function hash(markup, ctx) {
     var obj = {};
     lexical.patterns.hash.lastIndex = 0;
-    while(match = lexical.patterns.hash.exec(markup)){
-        var k = match[1], v = match[2];
-        if(!k) continue;
+    while (match = lexical.patterns.hash.exec(markup)) {
+        var k = match[1],
+            v = match[2];
+        if (!k) continue;
         obj[k] = ctx.get(v);
     }
     return obj;
 }
 
-function factory(name, markup){
-    var tag = tags[name];
-    if(!tag) throw new Error(`tag ${name} not found`);
-    
-    var instance = Object.create(_tagInstance);
-    instance.name = name;
-    instance.markup = markup;
-    instance.tag = tag;
-    return instance;
-}
+module.exports = function() {
+    var tags = {};
 
-function clear(){
-    tags = {};
-}
+    function register(name, tag) {
+        if (typeof tag.render !== 'function') {
+            throw new Error(`expect ${name}.render to be a function`);
+        }
+        tags[name] = tag;
+    }
 
-exports.parse = parse;
-exports.register = register;
-exports.hash = hash;
-exports.clear = clear;
+    function parse(str) {
+        var match = lexical.patterns.identifier.exec(str.trim());
+        if (!match) throw new Error('illegal tag: ' + str);
+
+        var tagInstance = factory(match[0], str);
+        return tagInstance;
+    }
+
+    function factory(name, markup) {
+        var tag = tags[name];
+        if (!tag) throw new Error(`tag ${name} not found`);
+
+        var instance = Object.create(_tagInstance);
+        instance.name = name;
+        instance.markup = markup;
+        instance.tag = tag;
+        return instance;
+    }
+
+    function clear() {
+        tags = {};
+    }
+
+    return {
+        parse, register, hash, clear
+    };
+};

test/filter.js

@@ -5,7 +5,7 @@ const expect = chai.expect;
 
 chai.use(sinonChai);
 
-var filter = require('../filter.js');
+var filter = require('../filter.js')();
 var context = require('../context.js');
 
 describe('filter', function() {

test/filters.js

@@ -0,0 +1,16 @@
+const chai = require("chai");
+const expect = chai.expect;
+
+var liquid = require('..')();
+
+describe('filters', function() {
+    var ctx = {
+        foo: 'bar',
+        arr: [-2, 'a']
+    };
+
+    it('should support abs', function() {
+        expect(liquid.render('{{ -3 | abs }}', ctx)).to.equal('3');
+        expect(liquid.render('{{ arr[0] | abs }}', ctx)).to.equal('2');
+    });
+});

test/lexical.js

@@ -14,7 +14,7 @@ describe('identifier', function() {
     it('should test number literal', function() {
         identifier.isLiteral('2.3').should.equal(true);
         identifier.isLiteral('.3').should.equal(true);
-        identifier.isLiteral('3.').should.equal(true);
+        identifier.isLiteral('-3.').should.equal(true);
         identifier.isLiteral('23').should.equal(true);
     });
 
@@ -58,7 +58,7 @@ describe('identifier', function() {
     it('should parse number literal', function() {
         identifier.parseLiteral('2.3').should.equal(2.3);
         identifier.parseLiteral('.32').should.equal(0.32);
-        identifier.parseLiteral('23.').should.equal(23);
+        identifier.parseLiteral('-23.').should.equal(-23);
         identifier.parseLiteral('23').should.equal(23);
     });
 

test/render.js

@@ -5,10 +5,10 @@ const expect = chai.expect;
 
 chai.use(sinonChai);
 
-var tag = require('../tag.js');
+var tag = require('../tag.js')();
 var context = require('../context.js');
-var filter = require('../filter');
-var render = require('../render.js');
+var filter = require('../filter')();
+var render = require('../render.js')(filter, tag);
 
 describe('render', function() {
     var ctx, htmlToken, tagToken, filterToken;

test/tag.js

@@ -4,7 +4,7 @@ var sinon = require("sinon");
 var expect = chai.expect;
 chai.use(sinonChai);
 
-var tag = require('../tag.js');
+var tag = require('../tag.js')();
 var context = require('../context.js');
 
 describe('tag', function() {