Designing a Secured Activex Control: Some Guidelines
An ActiveX control is a simple OLE object that was developed to unleash the power of Object Linking and Embedding. It empowers web browsers, particularly the IE, to display such objects. In the field of custom software application development, ActiveX controls have become the primary architecture. They are used in a variety of different containers including software development tools and end-user productivity tools.
Today, most regular Web pages, ActiveX components are built. At times, the download page, these components are downloaded, you start the computer operating system. Most ActiveX controls, including the animation, by the operating system to display rich multimedia content, streaming video is used, human resources, images, 3D video and many other rich content.
If you want to start to outsource software development to an offshore software development company, you must ensure that reliable checks based developer of components for creating solutions to create.Custom software application development experts design an ActiveX control with security in mind. This is because ActiveX controls tend to be extremely insecure in providing a feature. It will be important to note that such controls are COM (Component Object Model) objects. This means it can have access to the local file system and can read from the registry. If it gets downloaded, the chances of getting vulnerable to malicious attacks are more. This is because it can be used by any web application for its own benefits, whether malicious or for honest purposes.
Offshore software development company designed to take into account the safety of ActiveX controls. In the implementation of ActiveX controls, the experts to determine whether they can by other means similar functions. Some experts are more willing to write a DHTML behavior (dynamic HTML behavior) control.
An ActiveX control is a Win32 component and so it runs without any restrictions. Custom software application development experts find possible ways to limit the functionality of the control. Restricting the functionality can be the best way to prevent others from reusing the control, particularly for malicious purposes.
Posted in: dhtml| Tags: Software Application Control system web custom development object content activexJava: Object Oriented Programming
OOPs is a programming technique designed to simplify convoluted programming concepts. In fundamental nature, object-oriented programming revolves around the idea of user- and system-defined chunks of data, and controlled means of accessing and modifying those chunks. Object-oriented programming consists of Objects, Methods and Properties. An object is basically a black box which stores some information. Object may have a way for you to read that information and a way for you to write to, or change in sequence. It may also have other less noticeable ways of interacting with the information.
Some of the information in the object may essentially be directly easily reached; other information may necessitate you to use a method to access it - conceivably because the way the information is stored internally is of no use to you, or because only certain things can be written into that information space and the object needs to check that you're not going outside those limits. The directly reachable bits of information in the object are its properties. The difference between data accessed via properties and data accessed via methods is that with properties, you see accurately what you're doing to the object; with methods, unless you created the object yourself, you just see the effects of what you're doing.
Other JavaScripts site works will almost certainly happen too often, objects, events, methods and properties. This tutorial will learn from examples, without being too deeply into OOP terminology. However, you need a fundamental of these concepts to other JavaScript references used. Your web page document is an object. Each Web page can include table, form, button, an image or link on your site, is also an object. Each object has convinced properties. For example, the background color of the document is written document.bgColor. They would be too red, the color of your page code with scripts written in the line document.bgColor =
Most of the objects that they can have a specific collection. As another object, you can do something else you can turn on or turn off the light. This new document is opened in the documentation of the method. open () if
Object-oriented Javascript by Packt Publishing
The book, Object-Oriented JavaScript by Packt Publishing shows how to create scalable, reusable high-quality JavaScript applications and libraries using the concepts of object-oriented programming.
JavaScript is the language of the browser, but it is also used heavily in many other environments: server-side programming, desktop applications, application extensions and widgets. It's a pretty good deal: you learn a language and then code all kinds of different applications. While this book is a chapter specifically to be on the web browser environment including DOM, events have given, and AJAX tutorials, the rest is for all other environments.
This book treats JavaScript as a serious object-oriented language that shows you how robust build maintainable, and powerful libraries and applications. Along the way, we cover many of the recent innovations such as AJAX, JSON, and interesting design and programming patterns. After reading this book you will be prepared ace your JavaScript job interview, and even with a few bits that did not impress the interviewer might know. You should read this book if you want to take a position, your JavaScript skills to a new level of complexity.
The book requires no prior knowledge of JavaScript and works from the ground up to give you a thorough grounding in this powerful language. If you already know some JavaScript, you can find a lot of eyes, can opener, as you discover what you can do the language.
This book takes a do-it-yourself approach when it comes to writing a code, because the best way to really learn a programming language is by writing code. You are to type code into Firebug console to see the way it works and then changes, and encouraged to play with him. There are practice questions at the end of each chapter to help verify what you have learned.
You can read more about the book: here http://www.packtpub.com/object-oriented-javascript-applications-libraries/book
Posted in: javascript tutorial| Tags: Programming Javascript language object browser publishing object-oriented book packt orientedHow to: Remove an Object from Cache (Velocity)
The following examples show the ways you can remove objects from the cache. These procedures assume that you have already set up your cache cluster and have prepared your development environment to write cache-enabled applications. For more information about how to do this, see Installation and Deployment (Velocity) and How to: Prepare the Development Environment (Velocity).
For more details about the methods that are used in these examples, see these class library topics:
Remove
Item
Data in the cache is not encrypted and is available to any cache client with the appropriate configuration settings. We highly recommend that you secure the XML-based application configuration files, if used, to specify the cache client.
To remove an object from the cache
Make sure that the using statement (Imports in Visual Basic) is at the top of your application code to reference the Microsoft.Data.Caching namespace.
Create a DataCacheFactory object that is accessible to all parts of the application that need a cache client. We recommend reusing the same DataCacheFactory object to conserve memory and optimize performance.
Use the DataCacheFactory object to create a DataCache object (also referred to as the cache client) if you have not already done this. In the following examples, the DataCacheFactory instance is called CacheFactory1.
After you have the DataCache object, the Remove method or Item property may be used to remove an object from cache.
Example
The following example uses the Remove method to remove an object from cache.
Note
There are many other parameters available for this method. See the Remove class library for more information.
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//remove object in cache using key "Key0"
myCache.Remove("Key0");
The following example uses the Item property that has array notation to remove an object from cache.
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//remove object in cache using array notation
myCache["Key0"] = null;
How to: Update an Object in Cache (Velocity)
To update an object in cache
Make sure that the using statement (Imports in Visual Basic) is at the top of your application code to reference the Microsoft.Data.Caching namespace.
Create a DataCacheFactory object that is accessible to all parts of the application that need a cache client. We recommend reusing the same DataCacheFactory object to conserve memory and optimize performance.
Use the DataCacheFactory object to create a DataCache object (also referred to as the cache client) if you have not already done this. In the following examples, the DataCacheFactory instance is called CacheFactory1.
After you have the DataCache object, the Put method or Item property may be used to update an object in cache.
Example
The following example uses the Put method to add an object to cache. If the object is not present when this method is called, it will be added to the cache. If the object is already present, it will be replaced.
Note
There are many other parameters available for this method. See the Put class library for more information.
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//add or replace object in cache using key "Key0"
myCache.Put("Key0", "object replaced or added using Key0");
The following example uses the Item property that has array notation to add an object to cache. If the object is not present when this method is called, it will be added to the cache. If the object is already present, it will be replaced.
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//add or replace object in cache using array notation
myCache["Key0"] = "object replaced or added using Key0";
How to: Add an Object to Cache (Velocity)
The following examples show the ways you can add objects to the cache. These procedures assume that you have already set up your cache cluster and have prepared your development environment to write cache-enabled applications. For more information about how to do this, see Installation and Deployment (Velocity) and How to: Prepare the Development Environment (Velocity).
For more details about the methods that are used in these examples, follow these links to view the class library topics:
Add
Put
Item
Data in the cache is not encrypted and is available to any cache client with the appropriate configuration settings. We highly recommend that you secure the XML-based application configuration files, if used, to specify the cache client.
To add an object to cache
Make sure that the using statement (Imports in Visual Basic) is at the top of your application code to reference the Microsoft.Data.Caching namespace.
Create a DataCacheFactory object that is accessible to all parts of the application that need a cache client. We recommend reusing the same DataCacheFactory object to conserve memory and optimize performance.
Use the DataCacheFactory object to create a DataCache object (also referred to as the cache client) if you have not already done this. In the following examples, the DataCacheFactory instance is called CacheFactory1.
After you have the DataCache object, the Add method, Put method, or Item property may be called to add an object to the cache.
Example
The following example demonstrates how you can use the Add method to add an object to cache. You will get an exception if an object has already been cached by the same key (the first parameter).
Note
There are many other parameters available for this method. See the Add class library for more information.
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//add object to cache with key "Key0"
myCache.Add("Key0", "object added with Key0");
What Happens When a Cache Host Fails
If a cache host fails (assuming there are still a sufficient number of cache hosts available to keep the cluster running) nothing changes for the cache-enabled application. The cache cluster re-routes requests for the object to the cache host that maintained the secondary copy of the object. Within the cluster, the secondary copies of all the primary objects are then elevated to become the new primary objects. Then, secondary copies of those new primary objects are distributed to other cache hosts across the cluster. Secondary objects on the cache host that failed are replaced by new secondary objects and distributed across the cluster. This process also applies to regions.
For the high availability feature to help insulate your application from the failure of a cache host, at least three cache hosts must be members of the cache cluster. This is due to a strong consistency requirement stating that there must always be two copies of a cached object or region in a high availability-enabled cache. In order to maintain two copies of a cache or region, a high availability-enabled cache requires at least two cache hosts to function.
For example, perhaps you have created a high availability-enabled cached named HACache in a three-server cache cluster as shown in the following table. Assume that SQL Server was configured to perform the cluster management role (so that this example does not need to consider the potential loss of lead hosts).
| Time | Cache host 1 | Cache host 2 | Cache host 3 | HACache (high availability-enabled named cache) |
| T1 | running | running | running | available |
| T2 | running | running | stopped | available |
| T3 | running | stopped | stopped | not available |
At T1, when there are three cache hosts available, two copies of cached objects or regions can be stored on one of three available servers. At T2, when one cache server fails, HACache continues to be available because there are still two cache hosts available to store the two copies of cached objects or regions. At T3, when the second cache host fails, HACache becomes unavailable. This is because there is no longer another cache host available to store the second copy of cached objects or regions.