meteor soul

Meteor框架

https://www.meteor.com/

 

 

 

Meteor is an ultra-simple environment for building modern web applications.

With Meteor you write apps:

• in modern JavaScript
• that send data over the wire, rather than HTML
• using your choice of popular open-source libraries

   名字是流星的意思，意味着助理开发者，快速开发应用。

   同时还有数据更新很快的含义， 服务器端更新数据后，会很快的同步到所有观测此数据的所有客户端软件上。

DDP

https://github.com/meteor/meteor/blob/devel/packages/ddp/DDP.md

DDP is a protocol between a client and a server that supports two operations:

• Remote procedure calls by the client to the server.
• The client subscribing to a set of documents, and the server keeping the client informed about the contents of those documents as they change over time.

      meteor应用框架灵魂是其定义的一套 DDP协议（Meteor's Distributed Data Protocol），

      此协议的实现两个功能：

      1） 客户端可以调用服务器端的方法， 即支持远程调用， 一些后端的逻辑， 就可以写在前端， 打薄后端。

      2）客户端可以订阅服务器端的数据，当服务器端管理的数据改变后，所有订阅此数据的客户端都会被通知。

 

数据变更如下图， 客户端发起请求，改变服务端数据， 数据改变后，通知客户端更新数据。

 

     minimongo负责客户端数据的跟踪，正常情况会同服务器端的数据一致。

 

 

 NPM PACKAGE

ddp

https://www.npmjs.com/package/ddp

A callback style DDP (Meteor's Distributed Data Protocol) node client, originally based alansikora's node-js_ddp-client and Meteor's python client. Uses a more callback style approach.

 

客户端RPC 和 订阅。

 
  setTimeout(function () {
    /*
     * Call a Meteor Method
     */
    ddpclient.call(
      'deletePosts',             // name of Meteor Method being called
      ['foo', 'bar'],            // parameters to send to Meteor Method
      function (err, result) {   // callback which returns the method call results
        console.log('called function, result: ' + result);
      },
      function () {              // callback which fires when server has finished
        console.log('updated');  // sending any updated documents as a result of
        console.log(ddpclient.collections.posts);  // calling this method
      }
    );
  }, 3000);



  /*
   * Subscribe to a Meteor Collection
   */
  ddpclient.subscribe(
    'posts',                  // name of Meteor Publish function to subscribe to
    [],                       // any parameters used by the Publish function
    function () {             // callback when the subscription is complete
      console.log('posts complete:');
      console.log(ddpclient.collections.posts);
    }
  );
 
  /*
   * Observe a collection.
   */
  var observer = ddpclient.observe("posts");
  observer.added = function(id) {
    console.log("[ADDED] to " + observer.name + ":  " + id);
  };
  observer.changed = function(id, oldFields, clearedFields, newFields) {
    console.log("[CHANGED] in " + observer.name + ":  " + id);
    console.log("[CHANGED] old field values: ", oldFields);
    console.log("[CHANGED] cleared fields: ", clearedFields);
    console.log("[CHANGED] new fields: ", newFields);
  };
  observer.removed = function(id, oldValue) {
    console.log("[REMOVED] in " + observer.name + ":  " + id);
    console.log("[REMOVED] previous value: ", oldValue);
  };
  setTimeout(function() { observer.stop() }, 6000);
});
 

 

minimongo

https://www.npmjs.com/package/minimongo

    本地存储， mongo风格API

A client-side MongoDB implementation which supports basic queries, including some geospatial ones.

Uses code from Meteor.js minimongo package, reworked to support more geospatial queries and made npm+browserify friendly. It was forked in January 2014.

It is either IndexedDb backed (IndexedDb), WebSQL backed (WebSQLDb), Local storage backed (LocalStorageDb) or in memory only (MemoryDb).

 

 
// Require minimongo
var minimongo = require("minimongo");
 
var LocalDb = minimongo.MemoryDb;
 
// Create local db (in memory database with no backing)
db = new LocalDb();
 
// Add a collection to the database
db.addCollection("animals");
 
doc = { species: "dog", name: "Bingo" };
 
// Always use upsert for both inserts and modifies
db.animals.upsert(doc, function() {
    // Success:
 
    // Query dog (with no query options beyond a selector)
    db.animals.findOne({ species:"dog" }, {}, function(res) {
        console.log("Dog's name is: " + res.name);
    });
});