Object built-in object

Object FSWatcher

File system observation object

When the call fs.watch(target)is successful, the return type of object

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var fs = require("fs"); var watcher = fs.watch((eventType, filename) => { if (filename) { console.log(filename); // Prints: <Buffer ...> } }); watcher.close(); // 带回调地调用 fs.watch('./tmp', { encoding: 'buffer' }, (eventType, filename) => { if (filename) { console.log(filename); // Prints: <Buffer ...> } });

Inheritance

#lineWidth: 1.5 #font: Helvetica,sans-Serif #fontSize: 10 #leading: 1.6 #.this: fill=lightgray #.class: fill=white [<class>object|toString();toJSON()] [<class>EventEmitter|new EventEmitter()|EventEmitter|defaultMaxListeners|on();addListener();prependListener();once();prependOnceListener();off();removeListener();removeAllListeners();setMaxListeners();getMaxListeners();listeners();listenerCount();eventNames();emit()] [<this>FSWatcher|onchange;onclose;onerror|close()] [object] <:- [EventEmitter] [EventEmitter] <:- [FSWatcher] EventEmitter new EventEmitter() EventEmitter defaultMaxListeners on() addListener() prependListener() once() prependOnceListener() off() removeListener() removeAllListeners() setMaxListeners() getMaxListeners() listeners() listenerCount() eventNames() emit() FSWatcher onchange onclose onerror close() object toString() toJSON()

Static properties

defaultMaxListeners

Integer, the default global maximum number of listeners

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static Integer FSWatcher.defaultMaxListeners;

Member attributes

onchange

Function, query and bind "file change" event, equivalent to on("change", func);

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Function FSWatcher.onchange;

onclose

Function, query and bind the "watcher close" event, equivalent to on("close", func);

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Function FSWatcher.onclose;

onerror

Function, query and bind the "error occurred" event, equivalent to on("error", func);

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Function FSWatcher.onerror;

Member function

close

Close the Watcher and no longer receive corresponding file change processing events

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FSWatcher.close();

on

Bind an event handler to the object

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Object FSWatcher.on(String ev, Function func);

Call parameters:

  • ev: String, specify the name of the event
  • func: Function, specify event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Bind an event handler to the object

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Object FSWatcher.on(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

addListener

Bind an event handler to the object

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Object FSWatcher.addListener(String ev, Function func);

Call parameters:

  • ev: String, specify the name of the event
  • func: Function, specify event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Bind an event handler to the object

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Object FSWatcher.addListener(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

prependListener

Bind an event handler to the start of the object

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Object FSWatcher.prependListener(String ev, Function func);

Call parameters:

  • ev: String, specify the name of the event
  • func: Function, specify event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Bind an event handler to the start of the object

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Object FSWatcher.prependListener(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

once

Bind a one-time event processing function to the object, the one-time processing function will only be triggered once

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Object FSWatcher.once(String ev, Function func);

Call parameters:

  • ev: String, specify the name of the event
  • func: Function, specify event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Bind a one-time event processing function to the object, the one-time processing function will only be triggered once

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Object FSWatcher.once(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

prependOnceListener

Bind an event handler to the start of the object

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Object FSWatcher.prependOnceListener(String ev, Function func);

Call parameters:

  • ev: String, specify the name of the event
  • func: Function, specify event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Bind an event handler to the start of the object

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Object FSWatcher.prependOnceListener(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object property name will be used as the event name, and the property value will be used as the event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

off

Cancel the specified function from the object processing queue

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Object FSWatcher.off(String ev, Function func);

Call parameters:

  • ev: String, specify the name of the event
  • func: Function, specify event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Cancel all functions in the object processing queue

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Object FSWatcher.off(String ev);

Call parameters:

  • ev: String, specify the name of the event

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Cancel the specified function from the object processing queue

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Object FSWatcher.off(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object property name is used as the event name, and the property value is used as the event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

removeListener

Cancel the specified function from the object processing queue

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Object FSWatcher.removeListener(String ev, Function func);

Call parameters:

  • ev: String, specify the name of the event
  • func: Function, specify event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Cancel all functions in the object processing queue

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Object FSWatcher.removeListener(String ev);

Call parameters:

  • ev: String, specify the name of the event

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Cancel the specified function from the object processing queue

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Object FSWatcher.removeListener(Object map);

Call parameters:

  • map: Object, specify the event mapping relationship, the object property name is used as the event name, and the property value is used as the event processing function

Return result:

  • Object, Return the event object itself, which is convenient for chain call

removeAllListeners

Cancel all the listeners of all events from the object processing queue. If an event is specified, remove all the listeners of the specified event.

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Object FSWatcher.removeAllListeners(String ev);

Call parameters:

  • ev: String, specify the name of the event

Return result:

  • Object, Return the event object itself, which is convenient for chain call

Cancel all the listeners of all events from the object processing queue. If an event is specified, remove all the listeners of the specified event.

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Object FSWatcher.removeAllListeners(Array evs = []);

Call parameters:

  • evs: Array, specify the name of the event

Return result:

  • Object, Return the event object itself, which is convenient for chain call

setMaxListeners

The default limit of the number of listeners, only for compatibility

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FSWatcher.setMaxListeners(Integer n);

Call parameters:

  • n: Integer, specify the number of events

getMaxListeners

Get the default limit of the number of listeners, only for compatibility

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Integer FSWatcher.getMaxListeners();

Return result:

  • Integer, Return to the default limit number

listeners

Array of listeners for the specified event of the query object

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Array FSWatcher.listeners(String ev);

Call parameters:

  • ev: String, specify the name of the event

Return result:

  • Array, Returns an array of listeners for the specified event

listenerCount

The number of listeners for the specified event of the query object

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Integer FSWatcher.listenerCount(String ev);

Call parameters:

  • ev: String, specify the name of the event

Return result:

  • Integer, Returns the number of listeners for the specified event

The number of listeners for the specified event of the query object

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Integer FSWatcher.listenerCount(Value o, String ev);

Call parameters:

  • o: Value, specify the object of the query
  • ev: String, specify the name of the event

Return result:

  • Integer, Returns the number of listeners for the specified event

eventNames

Query the event name of the listener

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Array FSWatcher.eventNames();

Return result:

  • Array, Returns an array of event names

emit

Trigger an event actively

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Boolean FSWatcher.emit(String ev, ...args);

Call parameters:

  • ev: String, event name
  • args: ..., event parameters, which will be passed to the event handler

Return result:

  • Boolean, Return to the event trigger state, return true if there is a response event, otherwise return false

toString

Returns the string representation of the object, generally returns "[Native Object]", the object can be re-implemented according to its own characteristics

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String FSWatcher.toString();

Return result:

  • String, Returns the string representation of the object

toJSON

Returns the JSON format representation of the object, generally returns a collection of readable attributes defined by the object

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Value FSWatcher.toJSON(String key = "");

Call parameters:

  • key: String, unused

Return result:

  • Value, Returns a value containing JSON serializable