- 浏览: 489191 次
- 性别:
- 来自: 深圳
文章分类
- 全部博客 (185)
- job (15)
- linux/windows/unix/bash/shell (31)
- JAVA/J2EE/spring/hibernate/struts (30)
- VC/C++ (48)
- mysql/postgresql (6)
- php/jsp/asp/pear (1)
- FMS/flex/openlaszlo/red5/openmeetings (34)
- apache/tomcat/ftp/svn (6)
- xen/vm/Hadoop/cloudcompute (6)
- visual studio/eclipse/zendstudi/ant (8)
- others (1)
- windows异常处理 __try __except (1)
- (1)
- matlab (4)
- android (0)
最新评论
-
hongzhounlfd:
很透彻,很详细
依赖注入和控制反转 -
jefferyqjy:
谢谢~言简意赅~很明了!
依赖注入和控制反转 -
elderbrother:
太好了,谢谢
依赖注入和控制反转 -
east_zyd_zhao:
终于搞明白了
依赖注入和控制反转 -
Dremeng:
完美,一看就懂理解透彻
依赖注入和控制反转
Data Access, Manipulation, and Binding (openlaszlo)
LZX is designed to make it easy to write data-driven applications in which the values of data sources define the appearance and actions of the program. It does this through tags and APIs that allow you to get access to data over http, manipulate XML data in memory, and, significantly, bind the data hierarchy to the view hierarchy.
The following paragraphs summarize these key features of the LZX data-handling architecture. Chapter 36, Data, XML, and XPath discusses this subject in depth.
LZX programs manipulate XML-formatted data, which may be
-
embedded in the program text,
-
read in from a source when the program is compiled, or
-
read in from a source when the program is running.
XML sources are stored as objects called datasets. The <dataset>
tag has attributes that allow you to, for example, control caching on the client and server, include or exclude http headers, queue requests, and so forth. Objects created by <dataset>
are called lz.datasets. Methods on lz.datasets allow you to, for example, get and set query strings, parameters and so forth.
LZX employs datapointers, which are objects that represent pointers to nodes in datasets, to locate and manipulate content. Datapointers support a subset of XPath, which is a W3C standard specification for identifying paths of an XML document, or in the case of LZX, datasets. XPath uses a notation similar to the UNIX file-system to refer to nodes within a dataset. Datapointers can be repositioned using both procedural calls such as selectNext()
and by running an XPath request using setXPath()
.
Because it incorporates 精密的pattern matching, XPath notation is extremely 简明的and powerful. A single XPath expression can represent an 任意的large number of XML elements. Using methods such as addNode()
, setNodeName()
, setXpath()
, and selectParent()
, you can build and manipulate XML structures.
LZX provides a unique way of merging any arbitrarily shaped data hierarchy with any display hierarchy; this capability is called data binding. It is implemented in such a way that the data context of a child in the display hierarchy is implicitly the data context of its parent. Moreover, it is possible to 告知the system to create an arbitrary bit of view hierarchy to represent each element in a set of selected data.
The way this is done is by binding views to datapointers. A datapath
is a special case of datapointer that 明确的marries the data hierarchy to the view hierarchy, as in, for example:
<view name="bob" datapath="testdata:/*">
where testdata
refers to a dataset defined earlier in the program.
If this sounds a little abstract, well, it is. Therefore we'll keep the discussion short here and defer longer explanations to Chapter 37, Data Access and Binding; you may also want to examine some of the examples on http://www.laszlosystems.com/demos to get a feel for what can be done when applications are truly data-driven.
The key thing to understand is that while other languages and technologies have implemented merge algorithms that may appear similar on the surface, LZX's data binding is novel in the creation of program objects that retain a live connection with the entities of the data source.
发表评论
-
Red5安装和配置
2011-02-24 10:23 4012Red5安装和配置参考网页:http://www.cahblo ... -
基于Moodle平台的网站调查报告
2011-02-24 10:18 2532基于Moodle平台的网站调查报告 网站举例: ² 西南 ... -
moodle插件模块功能汇总
2011-02-24 10:03 4946Moodle官方提供654种插件或者模块moodle.org ... -
moodle 一体包安装手册(window)
2011-02-24 09:55 1251见附件 -
moodle中上传文件大小控制
2011-02-24 09:51 1803第一步:修改在php4下POST文件大小的限制1.编修php. ... -
linux下面安装moodle
2011-02-24 09:50 20531. 安装moodle运行 ... -
OpenMeetings安装文档
2011-02-15 11:09 2568OpenMeetings 是一个多语言可定制的视频会议和协作系 ... -
Compilation and Execution (openlaszlo)
2010-11-22 11:02 10217. Compilation and Exe ... -
Combining Tags and Script in LZX Programs (openlaszlo)
2010-11-22 11:01 12756. Combining Tags and ... -
Constraints(openlaszlo)
2010-11-22 10:18 1095constraint 表示可变的变量赋值形式 In LZX, ... -
Events and Methods (openlaszlo)
2010-11-22 09:35 13363. Events,Methods ,han ... -
Dimdim&Moodle安装配置文档节选
2010-11-09 17:40 2514Dimdim&Moodle安装配置文档节选 ... -
Red5如何响应rmpt的请求,中间涉及哪些关键类?
2010-11-01 15:35 1506Red5如何响应rmpt的请求,中间涉及哪些关键类? 响应请 ... -
red5的eclipse插件和用法
2010-10-30 20:56 1105参见http://www.red5.org/wiki/Red5 ... -
red5集群分析
2010-10-28 19:42 49891. 边(Edge ): 1. 边的主要作用是管理连接,并可以 ... -
red5源代码分析
2010-10-26 08:59 3827Red5如何响应rmpt的请求 ... -
创建第一个red5程序
2010-10-25 15:33 21111.下载最新版本的RED5 http://osflash.or ... -
openlaszlo中多媒体组件介绍
2010-10-14 15:50 1095在openlaszlo中我们可以处理图像,音视频等媒体文件。详 ... -
openlaszlo组件的简单介绍
2010-10-14 15:50 1256openlaszlo组件的简单介绍 收藏 在写laszlo ... -
创建一个简单的openlaszlo程序
2010-10-14 15:49 1030前面说到过openlaszlo程序是一组xml格式和javas ...
相关推荐
Phil Spector Data Manipulation R
This book is for all those who wish to learn about data manipulation from scratch and excel at aggregating data effectively. It is expected that you have basic knowledge of R and have previously done ...
How to access data from external sources such as files, databases, and web services Represent and manipulate time-series data and the many of the intricacies involved with this type of data How to ...
Data Manipulation with R
This book, Data Manipulation with R, is aimed at giving intermediate-to-advanced level users of R (who have knowledge about datasets) an opportunity to use state-of-the-art approaches in data ...
By the end of this book, you will have learned about text manipulation using stringr, how to extract data from twitter using twitteR library, how to clean raw data, and how to structure your raw data ...
介绍R语言用于数据处理,数据分析。这是一本经典的R语言数据操作典范
SAS Programming 2_ Data Manipulation Techniques SAS 必学!
The book contains much good information regarding the unique way in which R manipulates data objects. lt provides a complement to the many books illustrating statistical applications of R. It is clear...
This practical, example-oriented guide aims to discuss the split-apply-combine strategy in data manipulation, which is a faster data manipulation approach. After reading this book, you will not only ...
资源来自pypi官网。 资源全名:data_manipulation-0.17.tar.gz
This book teaches you techniques for both data manipulation and visualization and shows you the best way for developing new software packages for R. Beginning Data Science in R details how data ...
Learning-pandas-Get-to-grips-with-pandas-a-versatile-and-high-performance-Python-library-for-data-manipulation-analysis-and-discovery.pdf
pandas: Reading and Writing Data....Pages 103-130 pandas in Depth: Data Manipulation....Pages 131-165 Data Visualization with matplotlib....Pages 167-235 Machine Learning with scikit-learn....Pages ...
This book is intended to give you a hands-on introduction to the Spring Data project, whose core mission is to ...and manipulation tools but also use traditional databases in a state-of-the-art manner.
Data-structures and algorithms often cross your path when you compress files, compile programs, access databases, or simply use your favourite text editor. Understanding and implementing them can be ...
Data Manipulation with pandas.ipynb
数据处理的基本函数包。主要基于Pandas,Numpy。 import pandas as pd import numpy as np import pickle import datetime import os import hashlib import pika import json import time
fuzzy systems and neural networks, biomedical applications, autonomous land, sea and air vehicles, localization, tracking, SLAM, 3D perception, manipulation with multifinger hands, robotics, micro/...