node-js xml2js 插件

node-xml2js =========== Ever had the urge to parse XML? And wanted to access the data in some sane, easy way? Don't want to compile a C parser, for whatever reason? Then xml2js is what you're looking for! Description =========== Simple XML to JavaScript object converter. It supports bi-directional conversion. Uses [sax-js](https://github.com/isaacs/sax-js/) and [xmlbuilder-js](https://github.com/oozcitak/xmlbuilder-js/). Note: If you're looking for a full DOM parser, you probably want [JSDom](https://github.com/tmpvar/jsdom). Installation ============ Simplest way to install `xml2js` is to use [npm](http://npmjs.org), just `npm install xml2js` which will download xml2js and all dependencies. xml2js is also available via [Bower](http://bower.io/), just `bower install xml2js` which will download xml2js and all dependencies. Usage ===== No extensive tutorials required because you are a smart developer! The task of parsing XML should be an easy one, so let's make it so! Here's some examples. Shoot-and-forget usage ---------------------- You want to parse XML as simple and easy as possible? It's dangerous to go alone, take this: ```javascript var parseString = require('xml2js').parseString; var xml = "<root>Hello xml2js!</root>" parseString(xml, function (err, result) { console.dir(result); }); ``` Can't get easier than this, right? This works starting with `xml2js` 0.2.3. With CoffeeScript it looks like this: ```coffeescript {parseString} = require 'xml2js' xml = "<root>Hello xml2js!</root>" parseString xml, (err, result) -> console.dir result ``` If you need some special options, fear not, `xml2js` supports a number of options (see below), you can specify these as second argument: ```javascript parseString(xml, {trim: true}, function (err, result) { }); ``` Simple as pie usage ------------------- That's right, if you have been using xml-simple or a home-grown wrapper, this was added in 0.1.11 just for you: ```javascript var fs = require('fs'), xml2js = require('xml2js'); var parser = new xml2js.Parser(); fs.readFile(__dirname + '/foo.xml', function(err, data) { parser.parseString(data, function (err, result) { console.dir(result); console.log('Done'); }); }); ``` Look ma, no event listeners! You can also use `xml2js` from [CoffeeScript](https://github.com/jashkenas/coffeescript), further reducing the clutter: ```coffeescript fs = require 'fs', xml2js = require 'xml2js' parser = new xml2js.Parser() fs.readFile __dirname + '/foo.xml', (err, data) -> parser.parseString data, (err, result) -> console.dir result console.log 'Done.' ``` But what happens if you forget the `new` keyword to create a new `Parser`? In the middle of a nightly coding session, it might get lost, after all. Worry not, we got you covered! Starting with 0.2.8 you can also leave it out, in which case `xml2js` will helpfully add it for you, no bad surprises and inexplicable bugs! Promise usage ------------- ```javascript var xml2js = require('xml2js'); var xml = '<foo></foo>'; // With parser var parser = new xml2js.Parser(/* options */); parser.parseStringPromise(data).then(function (result) { console.dir(result); console.log('Done'); }) .catch(function (err) { // Failed }); // Without parser xml2js.parseStringPromise(data /*, options */).then(function (result) { console.dir(result); console.log('Done'); }) .catch(function (err) { // Failed }); ``` Parsing multiple files ---------------------- If you want to parse multiple files, you have multiple possibilities: * You can create one `xml2js.Parser` per file. That's the recommended one and is promised to always *just work*. * You can call `reset()` on your parser object. * You can hope everything goes well anyway. This behaviour is not guaranteed work always, if ever. Use option #1 if possible. Thanks! So you wanna some JSON? ----------------------- Just wrap the `result` object in a call to `JSON.stringify` like this `JSON.stringify(result)`. You get a string containing the JSON representation of the parsed object that you can feed to JSON-hungry consumers. Displaying results ------------------ You might wonder why, using `console.dir` or `console.log` the output at some level is only `[Object]`. Don't worry, this is not because `xml2js` got lazy. That's because Node uses `util.inspect` to convert the object into strings and that function stops after `depth=2` which is a bit low for most XML. To display the whole deal, you can use `console.log(util.inspect(result, false, null))`, which displays the whole result. So much for that, but what if you use [eyes](https://github.com/cloudhead/eyes.js) for nice colored output and it truncates the output with `…`? Don't fear, there's also a solution for that, you just need to increase the `maxLength` limit by creating a custom inspector `var inspect = require('eyes').inspector({maxLength: false})` and then you can easily `inspect(result)`. XML builder usage ----------------- Since 0.4.0, objects can be also be used to build XML: ```javascript var xml2js = require('xml2js'); var obj = {name: "Super", Surname: "Man", age: 23}; var builder = new xml2js.Builder(); var xml = builder.buildObject(obj); ``` At the moment, a one to one bi-directional conversion is guaranteed only for default configuration, except for `attrkey`, `charkey` and `explicitArray` options you can redefine to your taste. Writing CDATA is supported via setting the `cdata` option to `true`. To specify attributes: ```javascript var xml2js = require('xml2js'); var obj = {root: {$: {id: "my id"}, _: "my inner text"}}; var builder = new xml2js.Builder(); var xml = builder.buildObject(obj); ``` ### Adding xmlns attributes You can generate XML that declares XML namespace prefix / URI pairs with xmlns attributes. Example declaring a default namespace on the root element: ```javascript let obj = { Foo: { $: { "xmlns": "http://foo.com" } } }; ``` Result of `buildObject(obj)`: ```xml <Foo xmlns="http://foo.com"/> ``` Example declaring non-default namespaces on non-root elements: ```javascript let obj = { 'foo:Foo': { $: { 'xmlns:foo': 'http://foo.com' }, 'bar:Bar': { $: { 'xmlns:bar': 'http://bar.com' } } } } ``` Result of `buildObject(obj)`: ```xml <foo:Foo xmlns:foo="http://foo.com"> <bar:Bar xmlns:bar="http://bar.com"/> </foo:Foo> ``` Processing attribute, tag names and values ------------------------------------------ Since 0.4.1 you can optionally provide the parser with attribute name and tag name processors as well as element value processors (Since 0.4.14, you can also optionally provide the parser with attribute value processors): ```javascript function nameToUpperCase(name){ return name.toUpperCase(); } //transform all attribute and tag names and values to uppercase parseString(xml, { tagNameProcessors: [nameToUpperCase], attrNameProcessors: [nameToUpperCase], valueProcessors: [nameToUpperCase], attrValueProcessors: [nameToUpperCase]}, function (err, result) { // processed data }); ``` The `tagNameProcessors` and `attrNameProcessors` options accept an `Array` of functions with the following signature: ```javascript function (name){ //do something with `name` return name } ``` The `attrValueProcessors` and `valueProcessors` options accept an `Array` of functions with the following signature: ```javascript function (value, name) { //`name` will be the node name or attribute name //do something with `value`, (optionally) dependent on the node/attr name return value } ``` Some processors are provided out-of-the-box and can be found in `lib/processors.js`: - `normalize`: transforms the name to lowercase. (Automatically used when `options.normalize` is set to `true`) - `firstCharLowerCase`: transforms the first character to lower case. E.g. 'MyTagName' becomes 'myTagName' - `stripPrefix`: strips the xml