mirror of
https://github.com/thangisme/notes.git
synced 2024-11-01 04:27:17 -04:00
313 lines
9.4 KiB
Markdown
313 lines
9.4 KiB
Markdown
JS-YAML - YAML 1.2 parser / writer for JavaScript
|
|
=================================================
|
|
|
|
[](https://travis-ci.org/nodeca/js-yaml)
|
|
[](https://www.npmjs.org/package/js-yaml)
|
|
|
|
__[Online Demo](http://nodeca.github.com/js-yaml/)__
|
|
|
|
|
|
This is an implementation of [YAML](http://yaml.org/), a human friendly data
|
|
serialization language. Started as [PyYAML](http://pyyaml.org/) port, it was
|
|
completely rewritten from scratch. Now it's very fast, and supports 1.2 spec.
|
|
|
|
|
|
Installation
|
|
------------
|
|
|
|
### YAML module for node.js
|
|
|
|
```
|
|
npm install js-yaml
|
|
```
|
|
|
|
|
|
### CLI executable
|
|
|
|
If you want to inspect your YAML files from CLI, install js-yaml globally:
|
|
|
|
```
|
|
npm install -g js-yaml
|
|
```
|
|
|
|
#### Usage
|
|
|
|
```
|
|
usage: js-yaml [-h] [-v] [-c] [-t] file
|
|
|
|
Positional arguments:
|
|
file File with YAML document(s)
|
|
|
|
Optional arguments:
|
|
-h, --help Show this help message and exit.
|
|
-v, --version Show program's version number and exit.
|
|
-c, --compact Display errors in compact mode
|
|
-t, --trace Show stack trace on error
|
|
```
|
|
|
|
|
|
### Bundled YAML library for browsers
|
|
|
|
``` html
|
|
<!-- esprima required only for !!js/function -->
|
|
<script src="esprima.js"></script>
|
|
<script src="js-yaml.min.js"></script>
|
|
<script type="text/javascript">
|
|
var doc = jsyaml.load('greeting: hello\nname: world');
|
|
</script>
|
|
```
|
|
|
|
Browser support was done mostly for online demo. If you find any errors - feel
|
|
free to send pull requests with fixes. Also note, that IE and other old browsers
|
|
needs [es5-shims](https://github.com/kriskowal/es5-shim) to operate.
|
|
|
|
Notes:
|
|
|
|
1. We have no resources to support browserified version. Don't expect it to be
|
|
well tested. Don't expect fast fixes if something goes wrong there.
|
|
2. `!!js/function` in browser bundle will not work by default. If you really need
|
|
it - load `esprima` parser first (via amd or directly).
|
|
3. `!!bin` in browser will return `Array`, because browsers do not support
|
|
node.js `Buffer` and adding Buffer shims is completely useless on practice.
|
|
|
|
|
|
API
|
|
---
|
|
|
|
Here we cover the most 'useful' methods. If you need advanced details (creating
|
|
your own tags), see [wiki](https://github.com/nodeca/js-yaml/wiki) and
|
|
[examples](https://github.com/nodeca/js-yaml/tree/master/examples) for more
|
|
info.
|
|
|
|
``` javascript
|
|
yaml = require('js-yaml');
|
|
fs = require('fs');
|
|
|
|
// Get document, or throw exception on error
|
|
try {
|
|
var doc = yaml.safeLoad(fs.readFileSync('/home/ixti/example.yml', 'utf8'));
|
|
console.log(doc);
|
|
} catch (e) {
|
|
console.log(e);
|
|
}
|
|
```
|
|
|
|
|
|
### safeLoad (string [ , options ])
|
|
|
|
**Recommended loading way.** Parses `string` as single YAML document. Returns a JavaScript
|
|
object or throws `YAMLException` on error. By default, does not support regexps,
|
|
functions and undefined. This method is safe for untrusted data.
|
|
|
|
options:
|
|
|
|
- `filename` _(default: null)_ - string to be used as a file path in
|
|
error/warning messages.
|
|
- `onWarning` _(default: null)_ - function to call on warning messages.
|
|
Loader will throw on warnings if this function is not provided.
|
|
- `schema` _(default: `DEFAULT_SAFE_SCHEMA`)_ - specifies a schema to use.
|
|
- `FAILSAFE_SCHEMA` - only strings, arrays and plain objects:
|
|
http://www.yaml.org/spec/1.2/spec.html#id2802346
|
|
- `JSON_SCHEMA` - all JSON-supported types:
|
|
http://www.yaml.org/spec/1.2/spec.html#id2803231
|
|
- `CORE_SCHEMA` - same as `JSON_SCHEMA`:
|
|
http://www.yaml.org/spec/1.2/spec.html#id2804923
|
|
- `DEFAULT_SAFE_SCHEMA` - all supported YAML types, without unsafe ones
|
|
(`!!js/undefined`, `!!js/regexp` and `!!js/function`):
|
|
http://yaml.org/type/
|
|
- `DEFAULT_FULL_SCHEMA` - all supported YAML types.
|
|
- `json` _(default: false)_ - compatibility with JSON.parse behaviour. If true, then duplicate keys in a mapping will override values rather than throwing an error.
|
|
|
|
NOTE: This function **does not** understand multi-document sources, it throws
|
|
exception on those.
|
|
|
|
NOTE: JS-YAML **does not** support schema-specific tag resolution restrictions.
|
|
So, JSON schema is not as strict as defined in the YAML specification.
|
|
It allows numbers in any notation, use `Null` and `NULL` as `null`, etc.
|
|
Core schema also has no such restrictions. It allows binary notation for integers.
|
|
|
|
|
|
### load (string [ , options ])
|
|
|
|
**Use with care with untrusted sources**. The same as `safeLoad()` but uses
|
|
`DEFAULT_FULL_SCHEMA` by default - adds some JavaScript-specific types:
|
|
`!!js/function`, `!!js/regexp` and `!!js/undefined`. For untrusted sources you
|
|
must additionally validate object structure, to avoid injections:
|
|
|
|
``` javascript
|
|
var untrusted_code = '"toString": !<tag:yaml.org,2002:js/function> "function (){very_evil_thing();}"';
|
|
|
|
// I'm just converting that string, what could possibly go wrong?
|
|
require('js-yaml').load(untrusted_code) + ''
|
|
```
|
|
|
|
|
|
### safeLoadAll (string, iterator [ , options ])
|
|
|
|
Same as `safeLoad()`, but understands multi-document sources and apply
|
|
`iterator` to each document.
|
|
|
|
``` javascript
|
|
var yaml = require('js-yaml');
|
|
|
|
yaml.safeLoadAll(data, function (doc) {
|
|
console.log(doc);
|
|
});
|
|
```
|
|
|
|
|
|
### loadAll (string, iterator [ , options ])
|
|
|
|
Same as `safeLoadAll()` but uses `DEFAULT_FULL_SCHEMA` by default.
|
|
|
|
|
|
### safeDump (object [ , options ])
|
|
|
|
Serializes `object` as YAML document. Uses `DEFAULT_SAFE_SCHEMA`, so it will
|
|
throw exception if you try to dump regexps or functions. However, you can
|
|
disable exceptions by `skipInvalid` option.
|
|
|
|
options:
|
|
|
|
- `indent` _(default: 2)_ - indentation width to use (in spaces).
|
|
- `skipInvalid` _(default: false)_ - do not throw on invalid types (like function
|
|
in the safe schema) and skip pairs and single values with such types.
|
|
- `flowLevel` (default: -1) - specifies level of nesting, when to switch from
|
|
block to flow style for collections. -1 means block style everwhere
|
|
- `styles` - "tag" => "style" map. Each tag may have own set of styles.
|
|
- `schema` _(default: `DEFAULT_SAFE_SCHEMA`)_ specifies a schema to use.
|
|
- `sortKeys` _(default: `false`)_ - if `true`, sort keys when dumping YAML. If a
|
|
function, use the function to sort the keys.
|
|
- `lineWidth` _(default: `80`)_ - set max line width.
|
|
- `noRefs` _(default: `false`)_ - if `true`, don't convert duplicate objects into references
|
|
- `noCompatMode` _(default: `false`)_ - if `true` don't try to be compatible with older
|
|
yaml versions. Currently: don't quote "yes", "no" and so on, as required for YAML 1.1
|
|
|
|
The following table show availlable styles (e.g. "canonical",
|
|
"binary"...) available for each tag (.e.g. !!null, !!int ...). Yaml
|
|
ouput is shown on the right side after `=>` (default setting) or `->`:
|
|
|
|
``` none
|
|
!!null
|
|
"canonical" -> "~"
|
|
"lowercase" => "null"
|
|
"uppercase" -> "NULL"
|
|
"camelcase" -> "Null"
|
|
|
|
!!int
|
|
"binary" -> "0b1", "0b101010", "0b1110001111010"
|
|
"octal" -> "01", "052", "016172"
|
|
"decimal" => "1", "42", "7290"
|
|
"hexadecimal" -> "0x1", "0x2A", "0x1C7A"
|
|
|
|
!!bool
|
|
"lowercase" => "true", "false"
|
|
"uppercase" -> "TRUE", "FALSE"
|
|
"camelcase" -> "True", "False"
|
|
|
|
!!float
|
|
"lowercase" => ".nan", '.inf'
|
|
"uppercase" -> ".NAN", '.INF'
|
|
"camelcase" -> ".NaN", '.Inf'
|
|
```
|
|
|
|
Example:
|
|
|
|
``` javascript
|
|
safeDump (object, {
|
|
'styles': {
|
|
'!!null': 'canonical' // dump null as ~
|
|
},
|
|
'sortKeys': true // sort object keys
|
|
}
|
|
```
|
|
|
|
### dump (object [ , options ])
|
|
|
|
Same as `safeDump()` but without limits (uses `DEFAULT_FULL_SCHEMA` by default).
|
|
|
|
|
|
Supported YAML types
|
|
--------------------
|
|
|
|
The list of standard YAML tags and corresponding JavaScipt types. See also
|
|
[YAML tag discussion](http://pyyaml.org/wiki/YAMLTagDiscussion) and
|
|
[YAML types repository](http://yaml.org/type/).
|
|
|
|
```
|
|
!!null '' # null
|
|
!!bool 'yes' # bool
|
|
!!int '3...' # number
|
|
!!float '3.14...' # number
|
|
!!binary '...base64...' # buffer
|
|
!!timestamp 'YYYY-...' # date
|
|
!!omap [ ... ] # array of key-value pairs
|
|
!!pairs [ ... ] # array or array pairs
|
|
!!set { ... } # array of objects with given keys and null values
|
|
!!str '...' # string
|
|
!!seq [ ... ] # array
|
|
!!map { ... } # object
|
|
```
|
|
|
|
**JavaScript-specific tags**
|
|
|
|
```
|
|
!!js/regexp /pattern/gim # RegExp
|
|
!!js/undefined '' # Undefined
|
|
!!js/function 'function () {...}' # Function
|
|
```
|
|
|
|
Caveats
|
|
-------
|
|
|
|
Note, that you use arrays or objects as key in JS-YAML. JS does not allow objects
|
|
or array as keys, and stringifies (by calling .toString method) them at the
|
|
moment of adding them.
|
|
|
|
``` yaml
|
|
---
|
|
? [ foo, bar ]
|
|
: - baz
|
|
? { foo: bar }
|
|
: - baz
|
|
- baz
|
|
```
|
|
|
|
``` javascript
|
|
{ "foo,bar": ["baz"], "[object Object]": ["baz", "baz"] }
|
|
```
|
|
|
|
Also, reading of properties on implicit block mapping keys is not supported yet.
|
|
So, the following YAML document cannot be loaded.
|
|
|
|
``` yaml
|
|
&anchor foo:
|
|
foo: bar
|
|
*anchor: duplicate key
|
|
baz: bat
|
|
*anchor: duplicate key
|
|
```
|
|
|
|
|
|
Breaking changes in 2.x.x -> 3.x.x
|
|
----------------------------------
|
|
|
|
If you have not used __custom__ tags or loader classes and not loaded yaml
|
|
files via `require()` - no changes needed. Just upgrade library.
|
|
|
|
Otherwise, you should:
|
|
|
|
1. Replace all occurences of `require('xxxx.yml')` by `fs.readFileSync()` +
|
|
`yaml.safeLoad()`.
|
|
2. rewrite your custom tags constructors and custom loader
|
|
classes, to conform new API. See
|
|
[examples](https://github.com/nodeca/js-yaml/tree/master/examples) and
|
|
[wiki](https://github.com/nodeca/js-yaml/wiki) for details.
|
|
|
|
|
|
License
|
|
-------
|
|
|
|
View the [LICENSE](https://github.com/nodeca/js-yaml/blob/master/LICENSE) file
|
|
(MIT).
|