The Internet originated in the late s when the. United States Defense Department developed. ARPAnet (Advanced Research Projects Agency network) , an. ABSTRACT. You have been asked by your manager to port a legacy, fat-client application to the web. There are so many directions you can take in completing. PDF | Web application security remains a major roadblock to universal acceptance of the Web for many kinds of online transactions, especially since the recent.
|Language:||English, Spanish, Arabic|
|Genre:||Academic & Education|
|ePub File Size:||19.89 MB|
|PDF File Size:||12.55 MB|
|Distribution:||Free* [*Sign up for free]|
When put to the test, the term Web application has slightly different meanings to different people. Some believe a Web application is anything that uses Java. Complexity: Beginner Data Requirement: Use your own data Goal: Create a Web application using ArcGIS. Server Manager. You can use ArcGIS Server. Tobias Ratschiller. Till Gerken. With contributions by. Zend Technologies, LTD. Zeev Suraski. Andi Gutmans. Web Application. Development with PHP
In this article, Rachel Andrew takes a look at the tools that are available and shares her recommendations to help you find the tool that works best for you. Many web applications have the requirement of giving the user the ability to download something in PDF format. In the case of applications such as e-commerce stores , those PDFs have to be created using dynamic data, and be available immediately to the user. If you have a favorite tool or any experiences of your own to share, please add them to the comments below. In the case of an invoice, the user might be able to view the information online, then click to download a PDF for their records. You might be creating packing slips; once again, the information is already held within the system. You want to format that in a nice way for download and printing.
You want to format that in a nice way for download and printing.
Therefore, as CSS itself has specifications for printed materials, surely we should be able to use it? The simplest way a user can generate a PDF is via their browser. Sadly, this PDF is usually not altogether satisfactory! To start with, it will have the headers and footers which are automatically added when you print something from a webpage.
It will also be formatted according to your print stylesheet — assuming you have one. The problem we run into here is the poor support of the fragmentation specification in browsers; this may mean that the content of your pages breaks in unusual ways.
This means that you may be unable to prevent suboptimal breaking of content, with headers being left as the last item on the page, and so on. In addition, we have no ability to control the content in the page margin boxes, e.
These things are part of the Paged Media spec, but have not been implemented in any browser.
Printing Using Browser Rendering Engines There are ways to print to PDF using browser rendering engines, without going through the print menu in the browser, and ending up with headers and footers as if you had printed the document.
The most popular options in response to my tweet were wkhtmltopdf, and printing using headless Chrome and Puppeteer. It does this by using the WebKit rendering engine. We use wkhtmltopdf.
On this positive side, if you have a working print stylesheet for your content then it should also nicely output to PDF using this tool, and so a simple layout may well print very nicely.
Unfortunately, however, you will still run into the same problems as when printing directly from the web browser in terms of lack of support for the Paged Media specification and fragmentation properties, as you are still printing using a browser rendering engine. There are some flags that you can pass into wkhtmltopdf in order to add back some of the missing features that you would have by default using the Paged Media specification.
Web applications can be considered as a specific variant of client—server software where the client software is downloaded to the client machine when visiting the relevant web page, using standard procedures such as HTTP.
Client web software updates may happen each time the web page is visited. During the session, the web browser interprets and displays the pages, and acts as the universal client for any web application.
In the early days of the Web , each individual web page was delivered to the client as a static document, but the sequence of pages could still provide an interactive experience, as user input was returned through web form elements embedded in the page markup. However, every significant change to the web page required a round trip back to the server to refresh the entire page.
In , Macromedia introduced Flash , a vector animation player that could be added to browsers as a plug-in to embed animations on the web pages. It allowed the use of a scripting language to program interactions on the client side with no need to communicate with the server. In , the "web application" concept was introduced in the Java language in the Servlet Specification version 2.
In , the term Ajax was coined, and applications like Gmail started to make their client sides more and more interactive. In , HTML5 was finalized, which provides graphic and multimedia capabilities without the need of client side plug-ins.
HTML5 also enriched the semantic content of documents. These have significant importance in creating truly platform and browser independent rich web applications.
Many services have worked to combine all of these into a more familiar interface that adopts the appearance of an operating system. General purpose techniques such as drag and drop are also supported by these technologies. Web developers often use client-side scripting to add functionality, especially to create an interactive experience that does not require page reloading. Recently, technologies have been developed to coordinate client-side scripting with server-side technologies such as ASP.
Ajax , a web development technique using a combination of various technologies, is an example of technology which creates a more interactive experience.
Applications are usually broken into logical chunks called "tiers", where every tier is assigned a role. For more complex applications, a 3-tier solution may fall short, and it may be beneficial to use an n-tiered approach, where the greatest benefit is breaking the business logic, which resides on the application tier, into a more fine-grained model.
This allows the underlying database to be replaced without making any change to the other tiers. There are some who view a web application as a two-tier architecture. This can be a "smart" client that performs all the work and queries a "dumb" server, or a "dumb" client that relies on a "smart" server. An emerging strategy for application software companies is to provide web access to software previously distributed as local applications. Depending on the type of application, it may require the development of an entirely different browser-based interface, or merely adapting an existing application to use different presentation technology.
These programs allow the user to pay a monthly or yearly fee for use of a software application without having to install it on a local hard drive.
A company which follows this strategy is known as an application service provider ASP , and ASPs are currently receiving much attention in the software industry. Security breaches on these kinds of applications are a major concern because it can involve both enterprise information and private customer data.
Protecting these assets is an important part of any web application and there are some key operational areas that must be included in the development process. Building security into the applications from the beginning can be more effective and less disruptive in the long run. Cloud Computing model web applications are software as a service SaaS. There are business applications provided as SaaS for enterprises for fixed or usage dependent fee. Other web applications are offered free of charge, often generating income from advertisements shown in web application interface.
Writing web applications is often simplified by the use of web application frameworks such as Django , Ruby on Rails , and Symfony. These frameworks facilitate rapid application development by allowing a development team to focus on the parts of their application which are unique to their goals without having to resolve common development issues such as user management.
The use of web application frameworks can often reduce the number of errors in a program, both by making the code simpler, and by allowing one team to concentrate on the framework while another focuses on a specified use case. In applications which are exposed to constant hacking attempts on the Internet, security-related problems can be caused by errors in the program. In addition, there is potential for the development of applications on Internet operating systems , although currently there are not many viable platforms that fit this model.
Examples of browser applications are simple office software word processors , online spreadsheets , and presentation tools , but can also include more advanced applications such as project management, computer-aided design , video editing , and point-of-sale.