1 files changed, 333 insertions, 0 deletions
diff --git a/lib/template/index.js b/lib/template/index.js
new file mode 100644
index 0000000..128e171
--- /dev/null
+++ b/lib/template/index.js
@@ -0,0 +1,333 @@
+var _ = require('lodash');
+var path = require('path');
+var nunjucks = require('nunjucks');
+var parsers = require('gitbook-parsers');
+
+var Promise = require('../utils/promise');
+var error = require('../utils/error');
+var gitbook = require('../gitbook');
+var defaultBlocks = require('./blocks');
+
+// Return extension name for a specific block
+function blockExtName(name) {
+    return 'Block'+name+'Extension';
+}
+
+// Normalize the result of block process function
+function normBlockResult(blk) {
+    if (_.isString(blk)) blk = { body: blk };
+    return blk;
+}
+
+function TemplateEngine(book) {
+    this.book = book;
+    this.log = book.log;
+
+    this.env = new nunjucks.Environment(
+        this.loader,
+        {
+            // Escaping is done after by the asciidoc/markdown parser
+            autoescape: false,
+
+            // Syntax
+            tags: {
+                blockStart: '{%',
+                blockEnd: '%}',
+                variableStart: '{{',
+                variableEnd: '}}',
+                commentStart: '{###',
+                commentEnd: '###}'
+            }
+        }
+    );
+
+    // List of tags shortcuts
+    this.shortcuts = [];
+
+    // Map of blocks bodies (that requires post-processing)
+    this.blockBodies = {};
+
+    // Map of added blocks
+    this.blocks = {};
+
+    // Bind methods
+    _.bindAll(this);
+
+    // Add default blocks
+    this.addBlocks(defaultBlocks);
+}
+
+// Add a new custom filter
+TemplateEngine.prototype.addFilter = function(filterName, func) {
+    try {
+        this.env.getFilter(filterName);
+        this.log.error.ln('conflict in filters, "'+filterName+'" is already set');
+        return false;
+    } catch(e) {
+        // Filter doesn't exist
+    }
+
+    this.log.debug.ln('add filter "'+filterName+'"');
+    this.env.addFilter(filterName, this.bindContext(function() {
+        var ctx = this;
+        var args = Array.prototype.slice.apply(arguments);
+        var callback = _.last(args);
+
+        Promise()
+        .then(function() {
+            return func.apply(ctx, args.slice(0, -1));
+        })
+        .nodeify(callback);
+    }), true);
+    return true;
+};
+
+// Add multiple filters at once
+TemplateEngine.prototype.addFilters = function(filters) {
+    _.each(filters, function(filter, name) {
+        this.addFilter(name, filter);
+    }, this);
+};
+
+// Return true if a block is defined
+TemplateEngine.prototype.hasBlock = function(name) {
+    return this.env.hasExtension(blockExtName(name));
+};
+
+// Remove/Disable a block
+TemplateEngine.prototype.removeBlock = function(name) {
+    if (!this.hasBlock(name)) return;
+
+    // Remove nunjucks extension
+    this.env.removeExtension(blockExtName(name));
+
+    // Cleanup shortcuts
+    this.shortcuts = _.reject(this.shortcuts, {
+        block: name
+    });
+};
+
+// Add a block
+// Using the extensions of nunjucks: https://mozilla.github.io/nunjucks/api.html#addextension
+TemplateEngine.prototype.addBlock = function(name, block) {
+    var that = this, Ext, extName;
+
+    // Block can be a simple function
+    if (_.isFunction(block)) block = { process: block };
+
+    block = _.defaults(block || {}, {
+        shortcuts: [],
+        end: 'end'+name,
+        process: _.identity,
+        blocks: []
+    });
+
+    extName = blockExtName(name);
+
+    if (this.hasBlock(name) && !defaultBlocks[name]) {
+        this.log.warn.ln('conflict in blocks, "'+name+'" is already defined');
+    }
+
+    // Cleanup previous block
+    this.removeBlock(name);
+
+    this.log.debug.ln('add block \''+name+'\'');
+    this.blocks[name] = block;
+
+    Ext = function () {
+        this.tags = [name];
+
+        this.parse = function(parser, nodes) {
+            var body = null;
+            var lastBlockName = null;
+            var lastBlockArgs = null;
+            var allBlocks = block.blocks.concat([block.end]);
+            var subbodies = {};
+
+            var tok = parser.nextToken();
+            var args = parser.parseSignature(null, true);
+            parser.advanceAfterBlockEnd(tok.value);
+
+            while (1) {
+                // Read body
+                var currentBody = parser.parseUntilBlocks.apply(parser, allBlocks);
+
+                // Handle body with previous block name and args
+                if (lastBlockName) {
+                    subbodies[lastBlockName] = subbodies[lastBlockName] || [];
+                    subbodies[lastBlockName].push({
+                        body: currentBody,
+                        args: lastBlockArgs
+                    });
+                } else {
+                    body = currentBody;
+                }
+
+                // Read new block
+                lastBlockName = parser.peekToken().value;
+                if (lastBlockName == block.end) {
+                    break;
+                }
+
+                // Parse signature and move to the end of the block
+                lastBlockArgs = parser.parseSignature(null, true);
+                parser.advanceAfterBlockEnd(lastBlockName);
+            }
+            parser.advanceAfterBlockEnd();
+
+            var bodies = [body];
+            _.each(block.blocks, function(blockName) {
+                subbodies[blockName] = subbodies[blockName] || [];
+                if (subbodies[blockName].length === 0) {
+                    subbodies[blockName].push({
+                        args: new nodes.NodeList(),
+                        body: new nodes.NodeList()
+                    });
+                }
+
+                bodies.push(subbodies[blockName][0].body);
+            });
+
+            return new nodes.CallExtensionAsync(this, 'run', args, bodies);
+        };
+
+        this.run = function(context) {
+            var args = Array.prototype.slice.call(arguments, 1);
+            var callback = args.pop();
+
+            // Extract blocks
+            var blocks = args
+                .concat([])
+                .slice(-block.blocks.length);
+
+            // Eliminate blocks from list
+            if (block.blocks.length > 0) args = args.slice(0, -block.blocks.length);
+
+            // Extract main body and kwargs
+            var body = args.pop();
+            var kwargs = _.isObject(_.last(args))? args.pop() : {};
+
+            // Extract blocks body
+            var _blocks =  _.map(block.blocks, function(blockName, i){
+                return {
+                    name: blockName,
+                    body: blocks[i]()
+                };
+            });
+
+            Promise()
+            .then(function() {
+                return that.applyBlock(name, {
+                    body: body(),
+                    args: args,
+                    kwargs: kwargs,
+                    blocks: _blocks
+                }, context);
+            })
+
+            // process the block returned
+            .then(that.processBlock)
+            .nodeify(callback);
+        };
+    };
+
+    // Add the Extension
+    this.env.addExtension(extName, new Ext());
+
+    // Add shortcuts if any
+    if (!_.isArray(block.shortcuts)) {
+        block.shortcuts = [block.shortcuts];
+    }
+
+    _.each(block.shortcuts, function(shortcut) {
+        this.log.debug.ln('add template shortcut from "'+shortcut.start+'" to block "'+name+'" for parsers ', shortcut.parsers);
+        this.shortcuts.push({
+            block: name,
+            parsers: shortcut.parsers,
+            start: shortcut.start,
+            end: shortcut.end,
+            tag: {
+                start: name,
+                end: block.end
+            }
+        });
+    }, this);
+};
+
+// Add multiple blocks at once
+TemplateEngine.prototype.addBlocks = function(blocks) {
+    _.each(blocks, function(block, name) {
+        this.addBlock(name, block);
+    }, this);
+};
+
+// Apply a block to some content
+// This method result depends on the type of block (async or sync)
+TemplateEngine.prototype.applyBlock = function(name, blk, ctx) {
+    var func, block, r;
+
+    block = this.blocks[name];
+    if (!block) throw new Error('Block not found "'+name+'"');
+    if (_.isString(blk)) {
+        blk = {
+            body: blk
+        };
+    }
+
+    blk = _.defaults(blk, {
+        args: [],
+        kwargs: {},
+        blocks: []
+    });
+
+    // Bind and call block processor
+    func = this.bindContext(block.process);
+    r = func.call(ctx || {}, blk);
+
+    if (Promise.isPromise(r)) return r.then(normBlockResult);
+    else return normBlockResult(r);
+};
+
+
+// Render a string
+TemplateEngine.prototype.renderString = function(content, context, options) {
+    options = _.defaults(options || {}, {
+        path: null,
+        type: null
+    });
+
+    // Setup context for the template
+    context = _.extend({}, context, {
+        // Variables from book.json
+        book: this.book.config.get('variables'),
+
+        // Complete book.json
+        config: this.book.config.dump(),
+
+        // infos about gitbook
+        gitbook: {
+            version: gitbook.version,
+            generator: this.book.config.get('generator')
+        }
+    });
+
+    // Setup path and type
+    if (options.path) {
+        options.path = this.book.resolve(options.path);
+    }
+    if (!options.type && options.path) {
+        var parser = parsers.get(path.extname(options.path));
+        options.type = parser? parser.name : null;
+    }
+
+    // Replace shortcuts
+    //content = this.applyShortcuts(options.type, content);
+
+    return Promise.nfcall(this.env.renderString.bind(this.env), content, context, options)
+    .fail(function(err) {
+        throw error.enforce(err);
+    });
+};
+
+
+module.exports = TemplateEngine;