1 files changed, 264 insertions, 0 deletions
diff --git a/lib/models/templateBlock.js b/lib/models/templateBlock.js
new file mode 100644
index 0000000..ec7dc7c
--- /dev/null
+++ b/lib/models/templateBlock.js
@@ -0,0 +1,264 @@
+var is = require('is');
+var Immutable = require('immutable');
+
+var Promise = require('../utils/promise');
+var genKey = require('../utils/genKey');
+
+var NODE_ENDARGS = '%%endargs%%';
+
+var blockBodies = {};
+
+var TemplateBlock = Immutable.Record({
+    name:           String(),
+    end:            String(),
+    process:        Function(),
+    blocks:         Immutable.List(),
+    shortcuts:      Immutable.List(),
+    post:           null,
+    parse:          true
+});
+
+TemplateBlock.prototype.getName = function() {
+    return this.get('name');
+};
+
+TemplateBlock.prototype.getPost = function() {
+    return this.get('post');
+};
+
+TemplateBlock.prototype.getParse = function() {
+    return this.get('parse');
+};
+
+TemplateBlock.prototype.getEndTag = function() {
+    return this.get('end') || ('end' + this.getName());
+};
+
+TemplateBlock.prototype.getProcess = function() {
+    return this.get('process');
+};
+
+TemplateBlock.prototype.getBlocks = function() {
+    return this.get('blocks');
+};
+
+TemplateBlock.prototype.getShortcuts = function() {
+    return this.get('shortcuts');
+};
+
+/**
+    Return name for the nunjucks extension
+
+    @return {String}
+*/
+TemplateBlock.prototype.getExtensionName = function() {
+    return 'Block' + this.getName() + 'Extension';
+};
+
+/**
+    Return a nunjucks extension to represents this block
+
+    @return {Nunjucks.Extension}
+*/
+TemplateBlock.prototype.toNunjucksExt = function() {
+    var that = this;
+    var name = this.getName();
+    var endTag = this.getEndTag();
+    var blocks = this.getBlocks();
+
+    var Ext = function () {
+        this.tags = [name];
+
+        this.parse = function(parser, nodes) {
+            var lastBlockName = null;
+            var lastBlockArgs = null;
+            var allBlocks = blocks.concat([endTag]);
+
+            // Parse first block
+            var tok = parser.nextToken();
+            lastBlockArgs = parser.parseSignature(null, true);
+            parser.advanceAfterBlockEnd(tok.value);
+
+            var args = new nodes.NodeList();
+            var bodies = [];
+            var blockNamesNode = new nodes.Array(tok.lineno, tok.colno);
+            var blockArgCounts = new nodes.Array(tok.lineno, tok.colno);
+
+            // Parse while we found "end<block>"
+            do {
+                // Read body
+                var currentBody = parser.parseUntilBlocks.apply(parser, allBlocks);
+
+                // Handle body with previous block name and args
+                blockNamesNode.addChild(new nodes.Literal(args.lineno, args.colno, lastBlockName));
+                blockArgCounts.addChild(new nodes.Literal(args.lineno, args.colno, lastBlockArgs.children.length));
+                bodies.push(currentBody);
+
+                // Append arguments of this block as arguments of the run function
+                lastBlockArgs.children.forEach(function(child) {
+                    args.addChild(child);
+                });
+
+                // Read new block
+                lastBlockName = parser.nextToken().value;
+
+                // Parse signature and move to the end of the block
+                if (lastBlockName != endTag) {
+                    lastBlockArgs = parser.parseSignature(null, true);
+                }
+
+                parser.advanceAfterBlockEnd(lastBlockName);
+            } while (lastBlockName != endTag);
+
+            args.addChild(blockNamesNode);
+            args.addChild(blockArgCounts);
+            args.addChild(new nodes.Literal(args.lineno, args.colno, NODE_ENDARGS));
+
+            return new nodes.CallExtensionAsync(this, 'run', args, bodies);
+        };
+
+        this.run = function(context) {
+            var fnArgs = Array.prototype.slice.call(arguments, 1);
+
+            var args;
+            var blocks = [];
+            var bodies = [];
+            var blockNames;
+            var blockArgCounts;
+            var callback;
+
+            // Extract callback
+            callback = fnArgs.pop();
+
+            // Detect end of arguments
+            var endArgIndex = fnArgs.indexOf(NODE_ENDARGS);
+
+            // Extract arguments and bodies
+            args = fnArgs.slice(0, endArgIndex);
+            bodies = fnArgs.slice(endArgIndex + 1);
+
+            // Extract block counts
+            blockArgCounts = args.pop();
+            blockNames = args.pop();
+
+            // Recreate list of blocks
+            blockNames.forEach(function(name, i) {
+                var countArgs = blockArgCounts[i];
+                var blockBody = bodies.shift();
+
+                var blockArgs = countArgs > 0? args.slice(0, countArgs) : [];
+                args = args.slice(countArgs);
+                var blockKwargs = extractKwargs(blockArgs);
+
+                blocks.push({
+                    name: name,
+                    body: blockBody(),
+                    args: blockArgs,
+                    kwargs: blockKwargs
+                });
+            });
+
+            var mainBlock = blocks.shift();
+            mainBlock.blocks = blocks;
+
+            Promise()
+            .then(function() {
+                return that.applyBlock(mainBlock, context);
+            })
+            .then(function(result) {
+                return that.blockResultToHtml(result);
+            })
+            .nodeify(callback);
+        };
+    };
+
+    return Ext;
+};
+
+/**
+    Apply a block to a content
+    @param {Object} inner
+    @param {Object} context
+    @return {Promise<String>|String}
+*/
+TemplateBlock.prototype.applyBlock = function(inner, context) {
+    var processFn = this.getProcess();
+
+    inner = inner || {};
+    inner.args = inner.args || [];
+    inner.kwargs = inner.kwargs || {};
+    inner.blocks = inner.blocks || [];
+
+    var r = processFn.call(context, inner);
+
+    if (Promise.isPromiseAlike(r)) {
+        return r.then(this.handleBlockResult);
+    } else {
+        return this.handleBlockResult(r);
+    }
+};
+
+/**
+    Handle result from a block process function
+
+    @param {Object} result
+    @return {Object}
+*/
+TemplateBlock.prototype.handleBlockResult = function(result) {
+    if (is.string(result)) {
+        result = { body: result };
+    }
+
+    return result;
+};
+
+/**
+    Convert a block result to HTML
+
+    @param {Object} result
+    @return {String}
+*/
+TemplateBlock.prototype.blockResultToHtml = function(result) {
+    var parse = this.getParse();
+    var indexedKey;
+    var toIndex = (!parse) || (this.getPost() !== undefined);
+
+    if (toIndex) {
+        indexedKey = TemplateBlock.indexBlockResult(result);
+    }
+
+    // Parsable block, just return it
+    if (parse) {
+        return result.body;
+    }
+
+    // Return it as a position marker
+    return '{{-%' + indexedKey + '%-}}';
+
+};
+
+/**
+    Index a block result, and return the indexed key
+
+    @param {Object} blk
+    @return {String}
+*/
+TemplateBlock.indexBlockResult = function(blk) {
+    var key = genKey();
+    blockBodies[key] = blk;
+
+    return key;
+};
+
+/**
+    Extract kwargs from an arguments array
+
+    @param {Array} args
+    @return {Object}
+*/
+function extractKwargs(args) {
+    var last = args[args.length - 1];
+    return (is.object(last) && last.__keywords)? args.pop() : {};
+}
+
+module.exports = TemplateBlock;