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
<Fooxmlns="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:Fooxmlns:foo="http://foo.com">
<bar:Barxmlns: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 namespace prefix. E.g `<foo:Bar/>` will become 'Bar'.
(N.B.: the `xmlns` prefix is NOT stripped.)
-`parseNumbers`: parses integer-like strings as integers and float-like strings as floats
E.g. "0" becomes 0 and "15.56" becomes 15.56
-`parseBooleans`: parses boolean-like strings to booleans
E.g. "true" becomes true and "False" becomes false
Options
=======
Apart from the default settings, there are a number of options that can be
specified for the parser. Options are specified by ``new Parser({optionName:
value})``. Possible options are:
*`attrkey` (default: `$`): Prefix that is used to access the attributes.
Version 0.1 default was `@`.
*`charkey` (default: `_`): Prefix that is used to access the character
content. Version 0.1 default was `#`.
*`explicitCharkey` (default: `false`)
*`trim` (default: `false`): Trim the whitespace at the beginning and end of
text nodes.
*`normalizeTags` (default: `false`): Normalize all tag names to lowercase.
*`normalize` (default: `false`): Trim whitespaces inside text nodes.
*`explicitRoot` (default: `true`): Set this if you want to get the root
node in the resulting object.
*`emptyTag` (default: `''`): what will the value of empty nodes be.
*`explicitArray` (default: `true`): Always put child nodes in an array if
true; otherwise an array is created only if there is more than one.
*`ignoreAttrs` (default: `false`): Ignore all XML attributes and only create
text nodes.
*`mergeAttrs` (default: `false`): Merge attributes and child elements as
properties of the parent, instead of keying attributes off a child
attribute object. This option is ignored if `ignoreAttrs` is `true`.
*`validator` (default `null`): You can specify a callable that validates
the resulting structure somehow, however you want. See unit tests
for an example.
*`xmlns` (default `false`): Give each element a field usually called '$ns'
(the first character is the same as attrkey) that contains its local name
and namespace URI.
*`explicitChildren` (default `false`): Put child elements to separate
property. Doesn't work with `mergeAttrs = true`. If element has no children
then "children" won't be created. Added in 0.2.5.
*`childkey` (default `$$`): Prefix that is used to access child elements if
`explicitChildren` is set to `true`. Added in 0.2.5.
*`preserveChildrenOrder` (default `false`): Modifies the behavior of
`explicitChildren` so that the value of the "children" property becomes an
ordered array. When this is `true`, every node will also get a `#name` field
whose value will correspond to the XML nodeName, so that you may iterate
the "children" array and still be able to determine node names. The named
(and potentially unordered) properties are also retained in this
configuration at the same level as the ordered "children" array. Added in
0.4.9.
*`charsAsChildren` (default `false`): Determines whether chars should be
considered children if `explicitChildren` is on. Added in 0.2.5.
