var extend = require('deepmerge');
var fm = require('front-matter');
var path = require('path');
var through = require('through2');
var stripBom = require('strip-bom');
var processRoot = require('./processRoot');
module.exports = function() {
return through.obj(render.bind(this));
}
/**
* Renders a page with a layout. The page also has access to any loaded partials, helpers, or data.
* @param {object} file - Vinyl file being parsed.
* @param {string} enc - Vinyl file encoding.
* @param {function} cb - Callback that passes the rendered page through the stream.
*/
function render(file, enc, cb) {
try {
// Get the HTML for the current page and layout
var page = fm(stripBom(file.contents.toString()));
var pageData;
// Determine which layout to use
var basePath = path.relative(this.options.root, path.dirname(file.path));
var layout =
page.attributes.layout ||
(this.options.pageLayouts && this.options.pageLayouts[basePath]) ||
'default';
var layoutTemplate = this.layouts[layout];
if (!layoutTemplate) {
if (layout === 'default') {
throw new Error('Panini error: you must have a layout named "default".');
}
else {
throw new Error('Panini error: no layout named "'+layout+'" exists.');
}
}
// Now create Handlebars templates out of them
var pageTemplate = this.Handlebars.compile(page.body + '\n');
// Build page data with globals
pageData = extend({}, this.data);
// Add any data from stream plugins
pageData = (file.data) ? extend(pageData, file.data) : pageData;
// Add this page's front matter
pageData = extend(pageData, page.attributes);
// Finish by adding constants
pageData = extend(pageData, {
page: path.basename(file.path, path.extname(file.path)),
layout: layout,
root: processRoot(file.path, this.options.root)
});
// Add special ad-hoc partials for #ifpage and #unlesspage
this.Handlebars.registerHelper('ifpage', require('../helpers/ifPage')(pageData.page));
this.Handlebars.registerHelper('unlesspage', require('../helpers/unlessPage')(pageData.page));
// Finally, add the page as a partial called "body", and render the layout template
this.Handlebars.registerPartial('body', pageTemplate);
file.contents = new Buffer(layoutTemplate(pageData));
}
catch (e) {
if (layoutTemplate) {
// Layout was parsed properly so we can insert the error message into the body of the layout
this.Handlebars.registerPartial('body', 'Panini: template could not be parsed
\n {{error}}');
file.contents = new Buffer(layoutTemplate({ error: e }));
}
else {
// Not even once - write error directly into the HTML output so the user gets an error
// Maintain basic html structure to allow Livereloading scripts to be injected properly
file.contents = new Buffer('Panini error'+e+'
');
}
throw new Error('Panini: rendering error occured.\n' + e);
}
finally {
// This sends the modified file back into the stream
cb(null, file);
}
}