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# cordova-common
Expoeses shared functionality used by [cordova-lib](https://github.com/apache/cordova-lib/) and Cordova platforms.
## Exposed APIs
### `events`
Represents special instance of NodeJS EventEmitter which is intended to be used to post events to cordova-lib and cordova-cli
Usage:
```
var events = require('cordova-common').events;
events.emit('warn', 'Some warning message')
```
There are the following events supported by cordova-cli: `verbose`, `log`, `info`, `warn`, `error`.
### `CordovaError`
An error class used by Cordova to throw cordova-specific errors. The CordovaError class is inherited from Error, so CordovaError instances is also valid Error instances (`instanceof` check succeeds).
Usage:
```
var CordovaError = require('cordova-common').CordovaError;
throw new CordovaError('Some error message', SOME_ERR_CODE);
```
See [CordovaError](src/CordovaError/CordovaError.js) for supported error codes.
### `ConfigParser`
Exposes functionality to deal with cordova project `config.xml` files. For ConfigParser API reference check [ConfigParser Readme](src/ConfigParser/README.md).
Usage:
```
var ConfigParser = require('cordova-common').ConfigParser;
var appConfig = new ConfigParser('path/to/cordova-app/config.xml');
`PluginInfo` is a wrapper for cordova plugins' `plugin.xml` files. This class may be instantiated directly or via `PluginInfoProvider`. The difference is that `PluginInfoProvider` caches `PluginInfo` instances based on plugin source directory.
Usage:
```
var PluginInfo: require('cordova-common').PluginInfo;
var PluginInfoProvider: require('cordova-common').PluginInfoProvider;
// The following instances are equal
var plugin1 = new PluginInfo('path/to/plugin_directory');
var plugin2 = new PluginInfoProvider().get('path/to/plugin_directory');
console.log('The plugin ' + plugin1.id + ' has version ' + plugin1.version)
```
### `ActionStack`
Utility module for dealing with sequential tasks. Provides a set of tasks that are needed to be done and reverts all tasks that are already completed if one of those tasks fail to complete. Used internally by cordova-lib and platform's plugin installation routines.
Usage:
```
var ActionStack = require('cordova-common').ActionStack;
var stack = new ActionStack()
var action1 = stack.createAction(task1, [<taskparameters>], task1_reverter, [<reverter_parameters>]);
var action2 = stack.createAction(task2, [<taskparameters>], task2_reverter, [<reverter_parameters>]);
stack.push(action1);
stack.push(action2);
stack.process()
.then(function() {
// all actions succeded
})
.catch(function(error){
// One of actions failed with error
})
```
### `superspawn`
Module for spawning child processes with some advanced logic.
Usage:
```
var superspawn = require('cordova-common').superspawn;
superspawn.spawn('adb', ['devices'])
.then(function(devices){
// Do something...
})
```
### `xmlHelpers`
A set of utility methods for dealing with xml files.
Usage:
```
var xml = require('cordova-common').xmlHelpers;
var xmlDoc1 = xml.parseElementtreeSync('some/xml/file');
var xmlDoc2 = xml.parseElementtreeSync('another/xml/file');
xml.mergeXml(doc1, doc2); // doc2 now contains all the nodes from doc1
```
### Other APIs
The APIs listed below are also exposed but are intended to be only used internally by cordova plugin installation routines.
