AJAX allows web pages to request small bits of information from a server asynchronously in the background without reloading the entire page. It uses the XMLHttpRequest object in JavaScript to communicate with web servers. This makes applications faster and more interactive by allowing parts of a web page to change without reloading the whole page. Some benefits are more responsive applications and reduced bandwidth usage, while drawbacks include requiring JavaScript and increasing development complexity.
AJAX stands for Asynchronous JavaScript And XML. It allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes, without interfering with the display and behavior of the existing page. AJAX uses XMLHttpRequest object to request data from the server and JavaScript is used to display or use the data. The steps include creating an XMLHttpRequest object, making a request to the server using open() and send() methods, monitoring the response using onreadystatechange event handler, and updating the webpage with the response data.
AJAX allows for asynchronous communication between the user interface and web server to minimize unnecessary data transfer and reduce server load. It solves issues with unnecessary data transfers during page refreshes and synchronous processing that causes poor user experience. jQuery is a commonly used JavaScript library that simplifies AJAX implementation and development of dynamic web page elements like tabs.
This document provides an introduction to Ajax programming, including what Ajax is, how it differs from traditional HTTP paradigms, the key components needed for Ajax (XHTML, JavaScript, CSS), how to use the DOM and XMLHttpRequest objects to send and receive data from the server without refreshing the page, examples using the MochiKit JavaScript library to simplify Ajax programming, common pitfalls to avoid like breaking the back button and accessibility issues, and how Ajax can be used to make web pages more interactive and responsive.
This document provides an overview of AJAX (Asynchronous JavaScript and XML) and how it differs from traditional web applications. It discusses how AJAX allows asynchronous data retrieval, improving interactivity and user experience by avoiding full page refreshes. It then covers how AJAX works by using the XMLHttpRequest object to make asynchronous requests in the background. Examples of popular AJAX-powered sites are given, and code snippets demonstrate how to make AJAX requests from JavaScript and handle responses.
The document discusses the history and components of AJAX (Asynchronous JavaScript and XML). It notes that AJAX originated from technologies like XMLHttpRequest and iframes, and was popularized by sites like Gmail and Google Maps in the early 2000s. The core components that enable AJAX include JavaScript, the DOM, and XMLHttpRequest, with JavaScript serving as the glue between these components to asynchronously fetch and update web page content without reloading the entire page.
This document provides an overview of Ajax including:
- What Ajax is and how it works to make web pages more interactive
- Examples of popular sites that use Ajax like Gmail and Google Maps
- How Ajax applications differ from traditional applications by exchanging small amounts of data asynchronously rather than reloading the whole page
- Popular Ajax frameworks like jQuery that make development of Ajax applications easier
- Benefits of Ajax like richer interfaces, responsiveness, and network efficiency
AJAX allows web pages to request small bits of information from a server asynchronously in the background without reloading the entire page. It uses the XMLHttpRequest object in JavaScript to communicate with web servers. This makes applications faster and more interactive by allowing parts of a web page to change without reloading the whole page. Some benefits are more responsive applications and reduced bandwidth usage, while drawbacks include requiring JavaScript and increasing development complexity.
AJAX stands for Asynchronous JavaScript And XML. It allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes, without interfering with the display and behavior of the existing page. AJAX uses XMLHttpRequest object to request data from the server and JavaScript is used to display or use the data. The steps include creating an XMLHttpRequest object, making a request to the server using open() and send() methods, monitoring the response using onreadystatechange event handler, and updating the webpage with the response data.
AJAX allows for asynchronous communication between the user interface and web server to minimize unnecessary data transfer and reduce server load. It solves issues with unnecessary data transfers during page refreshes and synchronous processing that causes poor user experience. jQuery is a commonly used JavaScript library that simplifies AJAX implementation and development of dynamic web page elements like tabs.
This document provides an introduction to Ajax programming, including what Ajax is, how it differs from traditional HTTP paradigms, the key components needed for Ajax (XHTML, JavaScript, CSS), how to use the DOM and XMLHttpRequest objects to send and receive data from the server without refreshing the page, examples using the MochiKit JavaScript library to simplify Ajax programming, common pitfalls to avoid like breaking the back button and accessibility issues, and how Ajax can be used to make web pages more interactive and responsive.
This document provides an overview of AJAX (Asynchronous JavaScript and XML) and how it differs from traditional web applications. It discusses how AJAX allows asynchronous data retrieval, improving interactivity and user experience by avoiding full page refreshes. It then covers how AJAX works by using the XMLHttpRequest object to make asynchronous requests in the background. Examples of popular AJAX-powered sites are given, and code snippets demonstrate how to make AJAX requests from JavaScript and handle responses.
The document discusses the history and components of AJAX (Asynchronous JavaScript and XML). It notes that AJAX originated from technologies like XMLHttpRequest and iframes, and was popularized by sites like Gmail and Google Maps in the early 2000s. The core components that enable AJAX include JavaScript, the DOM, and XMLHttpRequest, with JavaScript serving as the glue between these components to asynchronously fetch and update web page content without reloading the entire page.
This document provides an overview of Ajax including:
- What Ajax is and how it works to make web pages more interactive
- Examples of popular sites that use Ajax like Gmail and Google Maps
- How Ajax applications differ from traditional applications by exchanging small amounts of data asynchronously rather than reloading the whole page
- Popular Ajax frameworks like jQuery that make development of Ajax applications easier
- Benefits of Ajax like richer interfaces, responsiveness, and network efficiency
Ajax allows for asynchronous data retrieval and manipulation without reloading the entire web page. It uses a combination of XMLHttpRequest, JavaScript, CSS, and HTML. This enables dynamic display and interaction on web pages by allowing asynchronous retrieval of data from the server in the background without interfering with the display and behavior of the existing page. The term "Ajax" was coined in 2005 but the underlying technologies like XMLHttpRequest had existed earlier. Ajax helped popularize the concept of Rich Internet Applications and is now commonly used in applications like Google Maps and Flickr to reload only parts of pages instead of the whole page for more dynamic and interactive experiences.
AJAX allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes without reloading the entire page. It uses a combination of technologies including XMLHttpRequest objects, JavaScript, DOM, and CSS. The XMLHttpRequest object sends and receives data from the server that can be used to update portions of a web page. This improves interactivity and allows for dynamic interfaces.
AJAX allows web pages to asynchronously update parts of a page without reloading the entire page. It uses a combination of XMLHttpRequest objects, JavaScript, DOM, and XML to exchange small amounts of data with a server in the background. This improves speed, usability, and interactivity compared to conventional web pages that reload the full page for any new content. Some examples of sites using AJAX are Google Maps, Gmail, YouTube, and Facebook.
The document discusses Ajax and RJS (Ruby JavaScript), describing that Ajax allows for mini web requests from JavaScript to update page content without reloading. It notes when Ajax should and should not be used, outlines the pros and cons, and provides examples of how to implement Ajax using the PrototypeJS library and RJS templates or inline JavaScript generation from the server.
This document discusses Ajax, which allows asynchronous updating of parts of a web page without reloading the entire page. It defines Ajax as using existing technologies like JavaScript, XML, CSS, and HTML. Key points:
- Ajax permits exchanging data with a server to update parts of a page without refreshing.
- It uses the XMLHttpRequest object to communicate asynchronously with server-side scripts and send/receive different data formats.
- Popular Ajax applications include live searches, autocomplete, chatting, and updating pages without refreshes.
- Ajax works by using JavaScript to fetch server data as needed without stopping other tasks. The returned data can then update the page.
Ajax allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes. This is done through the XMLHttpRequest object in JavaScript. By using Ajax, web pages feel more responsive because users can interact with the page while data is being loaded in the background without interfering with the display and behavior of the existing page.
AJAX is a web development technique that uses JavaScript and XML to make web pages feel more responsive by exchanging data with the server asynchronously in the background without reloading the entire page. It allows updating parts of a web page by retrieving data from the server and rendering it without disrupting the user experience. Some key technologies used in AJAX are XHTML, CSS, DOM, XML, and JavaScript. AJAX provides benefits like faster interactions and response times, real-time data validation, and reduced bandwidth usage compared to traditional page reloads.
This document provides an overview of Asynchronous JavaScript and XML (AJAX). It discusses how AJAX allows for asynchronous data retrieval from web servers in the background without interfering with the display and behavior of the existing page. This is done using the XMLHttpRequest object to make requests and callbacks that can update portions of the page without reloading. The document covers the basic components and uses of AJAX including real-time validation, autocomplete, and updating parts of pages without reloading. It also discusses some challenges with AJAX including breaking the back button and increasing code size.
This document provides an introduction to AJAX (Asynchronous JavaScript and XML). It discusses what AJAX is, why it was developed, how it works using the XMLHttpRequest object, security considerations, and alternatives like Flash. It also demonstrates how to encapsulate AJAX logic in JavaScript and how frameworks like JSF can be used to implement AJAX without writing JavaScript directly.
This document provides an introduction to AJAX (Asynchronous JavaScript and XML). It defines AJAX as a set of web development techniques using technologies like JavaScript, XML, HTML and CSS to create asynchronous web applications. AJAX allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes, without reloading the entire page. This is done using the XMLHttpRequest object in JavaScript. The document discusses the basics of how AJAX works, its advantages like improved interactivity and speed, as well as some disadvantages like dependency on JavaScript and security issues.
"AJAX = Asynchronous JavaScript and XML.
AJAX is a technique for creating fast and dynamic web pages.
AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.
Classic web pages, (which do not use AJAX) must reload the entire page if the content should change.
This contains:
*Getting started with New Dynamic Web Project
*Starting the tomcat server
*Running your project
*Changing the context root
*Changing welcome pages of your website
Ajax allows for asynchronous updating of parts of a web page without reloading the entire page. It was originally defined using XML and JavaScript but no longer requires either. While Ajax can improve functionality and reduce bandwidth usage, it also has drawbacks like not updating browser history and potentially overloading servers. Ajax works best for dynamic content updates on sites like Gmail, Google Maps, and social media sites but should not be relied on exclusively in case JavaScript fails. Developers need backup plans for when Ajax-reliant features do not function properly.
Web Component Development Using Servlet & JSP Technologies (EE6) - Chapter 1...WebStackAcademy
Asynchronous Servlets in Java:
An excessive number of threads running simultaneously in a Java application may consume a lot of resources. This is no exception for a web based Java application. Incoming requests are handled by dedicated HTTP worker threads which will then process those incoming requests until a response is finally assembled and sent back to the client.
Considering a web application scenario where the number of simultaneous users is expected to be very high, problems regarding resource consumption is what matters to active threads may become a real problem. HTTP worker threads belong to a dedicated pool, which may become exhausted. Additionally, the threads themselves have to consume their own resources, so incrementing the HTTP thread pool size to a (very) large number will also lead to system resources exhaustion: it simply does not scale.
This is where Asynchronous Servlets may be helpful. In short, an asynchronous servlet enables an application to process incoming requests in an asynchronous fashion: A given HTTP worker thread handles an incoming request and then passes the request to another background thread which in turn will be responsible for processing the request and send the response back to the client. The initial HTTP worker thread will return to the HTTP thread pool as soon as it passes the request to the background thread, so it becomes available to process another request.
This approach by itself may solve the problem of HTTP thread pool exhaustion, but will not solve the problem of system resources consumption. After all, another background thread was created for processing the request, so the number of simultaneous active threads will not decrease and the system resource consumption will not be improved.
The document discusses how to avoid caching issues with AJAX requests. AJAX applications frequently request the same URL from the server but the browser returns a cached response instead of making a new request. To solve this, a random parameter can be added to the URL on each request to trick the browser into thinking it is a new URL that has not been cached. This forces the browser to always make a fresh request to the server.
The document discusses AJAX (Asynchronous JavaScript and XML), which is a web development technique for building interactive web applications. It allows for asynchronous data retrieval, which means requests are made in the background without interfering with the display and behavior of the existing page. This improves responsiveness as users can interact with the page during data loading. The key components that AJAX uses are XML, HTML, CSS, DOM, and JavaScript. JavaScript plays the important role of binding these components together and enabling asynchronous communication with the server in the background.
Web Workers allow long-running scripts to run in the background without blocking the user interface. They allow CPU-intensive tasks to be performed off the main thread so they do not slow down interaction with the page. A Web Worker is initialized with a JavaScript file and runs on a separate thread than the main page. It communicates with the main page using postMessage() and can be terminated using terminate(). Errors are handled within the worker using an error handling function.
Advantages and disadvantages of an ajax based client applicationPlacinta Alin
Ajax is a technique for building interactive web applications where certain parts of a web page are updated without reloading the entire page. The key benefits of Ajax include reducing response times, allowing asynchronous data retrieval and updates, and making web applications feel more like desktop applications. Some common uses of Ajax include autocomplete functions, live searches, and chat applications. While Ajax provides benefits like improved interfaces and responsiveness, it also has disadvantages such as pages being hard to bookmark and search engines not indexing dynamically updated content. Developers must also consider browser compatibility, network latency, and security issues when implementing Ajax.
The document discusses Ajax, which uses a combination of technologies like XHTML, CSS, JavaScript, and XMLHttpRequest to retrieve data asynchronously from web servers without reloading the entire webpage. It allows web applications to be more interactive and responsive by exchanging small amounts of data with the server behind the scenes. While not new, Ajax became popular when Google used it to great effect in Gmail, showing how it could enhance the usability of web applications and create richer internet experiences without the need for plugins like Flash.
Ajax allows for asynchronous data retrieval and manipulation without reloading the entire web page. It uses a combination of XMLHttpRequest, JavaScript, CSS, and HTML. This enables dynamic display and interaction on web pages by allowing asynchronous retrieval of data from the server in the background without interfering with the display and behavior of the existing page. The term "Ajax" was coined in 2005 but the underlying technologies like XMLHttpRequest had existed earlier. Ajax helped popularize the concept of Rich Internet Applications and is now commonly used in applications like Google Maps and Flickr to reload only parts of pages instead of the whole page for more dynamic and interactive experiences.
AJAX allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes without reloading the entire page. It uses a combination of technologies including XMLHttpRequest objects, JavaScript, DOM, and CSS. The XMLHttpRequest object sends and receives data from the server that can be used to update portions of a web page. This improves interactivity and allows for dynamic interfaces.
AJAX allows web pages to asynchronously update parts of a page without reloading the entire page. It uses a combination of XMLHttpRequest objects, JavaScript, DOM, and XML to exchange small amounts of data with a server in the background. This improves speed, usability, and interactivity compared to conventional web pages that reload the full page for any new content. Some examples of sites using AJAX are Google Maps, Gmail, YouTube, and Facebook.
The document discusses Ajax and RJS (Ruby JavaScript), describing that Ajax allows for mini web requests from JavaScript to update page content without reloading. It notes when Ajax should and should not be used, outlines the pros and cons, and provides examples of how to implement Ajax using the PrototypeJS library and RJS templates or inline JavaScript generation from the server.
This document discusses Ajax, which allows asynchronous updating of parts of a web page without reloading the entire page. It defines Ajax as using existing technologies like JavaScript, XML, CSS, and HTML. Key points:
- Ajax permits exchanging data with a server to update parts of a page without refreshing.
- It uses the XMLHttpRequest object to communicate asynchronously with server-side scripts and send/receive different data formats.
- Popular Ajax applications include live searches, autocomplete, chatting, and updating pages without refreshes.
- Ajax works by using JavaScript to fetch server data as needed without stopping other tasks. The returned data can then update the page.
Ajax allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes. This is done through the XMLHttpRequest object in JavaScript. By using Ajax, web pages feel more responsive because users can interact with the page while data is being loaded in the background without interfering with the display and behavior of the existing page.
AJAX is a web development technique that uses JavaScript and XML to make web pages feel more responsive by exchanging data with the server asynchronously in the background without reloading the entire page. It allows updating parts of a web page by retrieving data from the server and rendering it without disrupting the user experience. Some key technologies used in AJAX are XHTML, CSS, DOM, XML, and JavaScript. AJAX provides benefits like faster interactions and response times, real-time data validation, and reduced bandwidth usage compared to traditional page reloads.
This document provides an overview of Asynchronous JavaScript and XML (AJAX). It discusses how AJAX allows for asynchronous data retrieval from web servers in the background without interfering with the display and behavior of the existing page. This is done using the XMLHttpRequest object to make requests and callbacks that can update portions of the page without reloading. The document covers the basic components and uses of AJAX including real-time validation, autocomplete, and updating parts of pages without reloading. It also discusses some challenges with AJAX including breaking the back button and increasing code size.
This document provides an introduction to AJAX (Asynchronous JavaScript and XML). It discusses what AJAX is, why it was developed, how it works using the XMLHttpRequest object, security considerations, and alternatives like Flash. It also demonstrates how to encapsulate AJAX logic in JavaScript and how frameworks like JSF can be used to implement AJAX without writing JavaScript directly.
This document provides an introduction to AJAX (Asynchronous JavaScript and XML). It defines AJAX as a set of web development techniques using technologies like JavaScript, XML, HTML and CSS to create asynchronous web applications. AJAX allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes, without reloading the entire page. This is done using the XMLHttpRequest object in JavaScript. The document discusses the basics of how AJAX works, its advantages like improved interactivity and speed, as well as some disadvantages like dependency on JavaScript and security issues.
"AJAX = Asynchronous JavaScript and XML.
AJAX is a technique for creating fast and dynamic web pages.
AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.
Classic web pages, (which do not use AJAX) must reload the entire page if the content should change.
This contains:
*Getting started with New Dynamic Web Project
*Starting the tomcat server
*Running your project
*Changing the context root
*Changing welcome pages of your website
Ajax allows for asynchronous updating of parts of a web page without reloading the entire page. It was originally defined using XML and JavaScript but no longer requires either. While Ajax can improve functionality and reduce bandwidth usage, it also has drawbacks like not updating browser history and potentially overloading servers. Ajax works best for dynamic content updates on sites like Gmail, Google Maps, and social media sites but should not be relied on exclusively in case JavaScript fails. Developers need backup plans for when Ajax-reliant features do not function properly.
Web Component Development Using Servlet & JSP Technologies (EE6) - Chapter 1...WebStackAcademy
Asynchronous Servlets in Java:
An excessive number of threads running simultaneously in a Java application may consume a lot of resources. This is no exception for a web based Java application. Incoming requests are handled by dedicated HTTP worker threads which will then process those incoming requests until a response is finally assembled and sent back to the client.
Considering a web application scenario where the number of simultaneous users is expected to be very high, problems regarding resource consumption is what matters to active threads may become a real problem. HTTP worker threads belong to a dedicated pool, which may become exhausted. Additionally, the threads themselves have to consume their own resources, so incrementing the HTTP thread pool size to a (very) large number will also lead to system resources exhaustion: it simply does not scale.
This is where Asynchronous Servlets may be helpful. In short, an asynchronous servlet enables an application to process incoming requests in an asynchronous fashion: A given HTTP worker thread handles an incoming request and then passes the request to another background thread which in turn will be responsible for processing the request and send the response back to the client. The initial HTTP worker thread will return to the HTTP thread pool as soon as it passes the request to the background thread, so it becomes available to process another request.
This approach by itself may solve the problem of HTTP thread pool exhaustion, but will not solve the problem of system resources consumption. After all, another background thread was created for processing the request, so the number of simultaneous active threads will not decrease and the system resource consumption will not be improved.
The document discusses how to avoid caching issues with AJAX requests. AJAX applications frequently request the same URL from the server but the browser returns a cached response instead of making a new request. To solve this, a random parameter can be added to the URL on each request to trick the browser into thinking it is a new URL that has not been cached. This forces the browser to always make a fresh request to the server.
The document discusses AJAX (Asynchronous JavaScript and XML), which is a web development technique for building interactive web applications. It allows for asynchronous data retrieval, which means requests are made in the background without interfering with the display and behavior of the existing page. This improves responsiveness as users can interact with the page during data loading. The key components that AJAX uses are XML, HTML, CSS, DOM, and JavaScript. JavaScript plays the important role of binding these components together and enabling asynchronous communication with the server in the background.
Web Workers allow long-running scripts to run in the background without blocking the user interface. They allow CPU-intensive tasks to be performed off the main thread so they do not slow down interaction with the page. A Web Worker is initialized with a JavaScript file and runs on a separate thread than the main page. It communicates with the main page using postMessage() and can be terminated using terminate(). Errors are handled within the worker using an error handling function.
Advantages and disadvantages of an ajax based client applicationPlacinta Alin
Ajax is a technique for building interactive web applications where certain parts of a web page are updated without reloading the entire page. The key benefits of Ajax include reducing response times, allowing asynchronous data retrieval and updates, and making web applications feel more like desktop applications. Some common uses of Ajax include autocomplete functions, live searches, and chat applications. While Ajax provides benefits like improved interfaces and responsiveness, it also has disadvantages such as pages being hard to bookmark and search engines not indexing dynamically updated content. Developers must also consider browser compatibility, network latency, and security issues when implementing Ajax.
The document discusses Ajax, which uses a combination of technologies like XHTML, CSS, JavaScript, and XMLHttpRequest to retrieve data asynchronously from web servers without reloading the entire webpage. It allows web applications to be more interactive and responsive by exchanging small amounts of data with the server behind the scenes. While not new, Ajax became popular when Google used it to great effect in Gmail, showing how it could enhance the usability of web applications and create richer internet experiences without the need for plugins like Flash.
El documento describe la carrera de ingeniería ambiental. La ingeniería ambiental estudia los problemas ambientales de forma integral considerando factores ecológicos, sociales, económicos y tecnológicos para promover un desarrollo sostenible. Los ingenieros ambientales trabajan en empresas, gobiernos y organizaciones para evaluar y mitigar el impacto de la actividad humana en el medio ambiente y proponer soluciones a problemas ambientales utilizando la tecnología.
El documento habla sobre la historia y funcionamiento de los virus informáticos. Explica que el primer virus se llamó Creeper y se creó en 1972 para replicarse a través de una máquina IBM. Los virus informáticos se replican al ejecutar programas infectados y residen en la memoria RAM, infectando otros archivos ejecutables. Existen dos formas de contagio: cuando el usuario ejecuta inadvertidamente un programa malicioso, o cuando el virus se replica a través de redes.
The document summarizes the arrival of Luke Carrington Showalter, the newborn son of Sandy and Jamie Showalter, owners of Showalter Flying Service. It also announces an upcoming 5K run on April 20th to benefit Angel Flight Southeast and provides other news items from Showalter Flying Service including a conference attended by staff and a volunteer opportunity in the Bahamas.
DB2 ofrece ventajas como tiempos de respuesta rápidos, recuperación de datos usando índices, seguridad de datos, y administración desde cualquier estación de trabajo. DB2 también distribuye y almacena la ubicación de datos para facilitar la administración de bases de datos grandes particionadas. Sin embargo, errores del sistema operativo pueden causar que DB2 falle.
Is filing bankruptcy affect my credit rating?xiojjamestaowcy
Filing for bankruptcy will negatively impact your credit rating. While bankruptcy initially lowers your credit score, it can be the first step to eventually repairing your credit over time. The document provides a link to a website for bankruptcy lawyers that may offer helpful information related to filing for bankruptcy.
El documento discute cómo Internet no tiene un centro ni periferia fija, y cómo cualquiera puede considerarse el centro aunque no sepa la extensión de los alrededores. También señala que la desigualdad más importante es el acceso desigual a recursos informáticos entre países, lo que dificulta extender la cultura y oportunidades educativas a las mayorías en países menos desarrollados.
Este documento define y explica conceptos clave relacionados con la metodología de la acción didáctica, como proceso didáctico, método, estrategia, actividad, tarea, procedimiento, mediación e interacción. También describe enfoques didácticos como la globalización e interdisciplinariedad, y cómo organizar contenidos curriculares en el aula a través de unidades didácticas, centros de interés y proyectos de trabajo.
La documento presenta información sobre Estela Zavarce, una estudiante de la Escuela de Administración y Relaciones Industriales de la Universidad "Fermín Toro" en Cabudare, Estado Lara, Venezuela, que cursa estudios en Economía.
Ajax allows web pages to asynchronously update parts of a page by exchanging data with a web server behind the scenes without reloading the entire page. It uses a combination of technologies like HTML/XHTML, CSS, DOM, XML, JavaScript, and the XMLHttpRequest object. This allows faster and more interactive web applications by reducing the amount of data sent and received.
This document provides a history of AJAX and an overview of how it works. It discusses how AJAX enables asynchronous data retrieval, allowing parts of web pages to update without reloading the entire page. It then provides examples of using the XMLHttpRequest object to make requests to a server and retrieve data to dynamically update a web page. The document also covers browser support for AJAX and examples of server-side scripts to handle AJAX requests.
AJAX allows web pages to update parts of a page without reloading the entire page. It uses a combination of HTML, CSS, JavaScript, XML, and XHR to asynchronously retrieve data from a web server in the background without interfering with the display and behavior of the existing page. The XMLHttpRequest object sends and receives data from the server, and JavaScript is used to display or modify the HTML page without reloading. Examples of AJAX applications include Google Maps, Gmail, YouTube, and Facebook tabs.
The document discusses Ajax and how it allows asynchronous communication with a server without reloading the entire web page. It covers the basic objects and methods needed, including the XMLHttpRequest object. The typical Ajax process involves creating an XMLHttpRequest object, sending it to the server, and triggering a response function when the server responds to update the display without reloading the page.
Ajax allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes. It uses a combination of technologies including HTML, CSS, JavaScript, XML, and the XMLHttpRequest object. The XMLHttpRequest object allows JavaScript to make HTTP requests to the server. This allows data to be retrieved from the server to update parts of the web page without reloading the entire page. Ajax removes the need to do full page reloads to get new data from the server, resulting in faster and more interactive web applications.
The document discusses Asynchronous JavaScript and XML (AJAX) technology. It defines AJAX and explains its purpose is to update parts of a web page asynchronously without reloading the entire page. It describes the technologies used including JavaScript, XML, and server-side languages. It provides examples of how AJAX works and the processes involved, including using the XMLHttpRequest object to asynchronously send and receive data from the server in the background. The advantages and disadvantages of AJAX are also summarized.
AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server in the background without reloading the entire page. It uses a combination of XMLHttpRequest object, JavaScript, DOM, and XML to retrieve data from the server and update parts of the web page. The XMLHttpRequest object sends and receives data from the server in the background, and JavaScript code can access and use the received data to make changes on the web page via DOM without reloading.
AJAX allows for asynchronous data retrieval and updating of parts of a web page without reloading the entire page. It uses a combination of technologies including XML, JavaScript, CSS, HTML and the XMLHttpRequest object. The XMLHttpRequest object makes asynchronous HTTP requests to the server in the background and retrieves data from the server. This allows updating parts of the web page without interrupting the user's operation.
AJAX allows for asynchronous data retrieval and interaction with web pages. It uses a combination of XHTML, CSS, JavaScript, and the XMLHttpRequest object to retrieve and update content without reloading the entire page. The XMLHttpRequest object sends and receives data from the server in the background without interfering with the display and behavior of the existing page. This allows for asynchronous updating of content within a page.
Ajax allows web pages to asynchronously update parts of a web page without reloading the entire page. It uses the XMLHttpRequest object to make HTTP requests and retrieve data from a web server behind the scenes. This allows updating portions of a page quickly without interfering with the display and behavior of the existing page. Common uses of Ajax include form validation, retrieving search results, and updating parts of interactive interfaces without refreshing the whole page.
AJAX allows web pages to be updated asynchronously by exchanging data with a server behind the scenes without reloading the whole page. It uses a combination of technologies including XMLHttpRequest objects, JavaScript, HTML and CSS. The XMLHttpRequest object performs asynchronous requests in the background to retrieve data from the server and update portions of the web page without reloading the entire page.
The document discusses Java Server Pages (JSP) technology. It introduces JSP, describes how JSP pages are processed by the web server, and discusses key aspects of JSP including implicit objects, control flow statements, operators, and declaring variables and methods. JSP pages combine HTML/XHTML code with embedded Java code to create dynamic web content. The Java code in JSP is executed on the server to generate the HTML response sent to the client.
JavaServer Pages (JSP) allow developers to insert Java code into HTML pages using special tags. A JSP file is converted into a servlet class by the JSP container. The servlet class is then executed to generate an HTML response. The JSP lifecycle includes compilation, initialization, execution, and cleanup similar to a servlet lifecycle. Apache Tomcat is an open source web server that implements the JSP and servlet specifications and includes components like Catalina, Coyote, and Jasper to handle servlet container functions, HTTP connections, and JSP compilation respectively.
Ajax allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes without reloading the entire page. It works by using JavaScript and DOM manipulation on the client-side to update parts of a web page after new information has been received from the server. This tutorial introduces the basics of Ajax and shows how to send and receive data from a server without requiring a form submission. It demonstrates making an XMLHttpRequest object, defining a function to handle the server response, checking the request status, and retrieving the response text to dynamically update an HTML form field.
The document discusses Ajax, which uses a combination of technologies like HTML, JavaScript, XML and CSS to retrieve data from a server asynchronously in the background without interfering with the display and behavior of the existing page. It explains what Ajax is, the technologies used, how it works using XMLHttpRequest object, and provides an example of creating an Ajax request and handling responses from the server. It also touches upon drawbacks and browser compatibility issues with Ajax.
The document provides an overview of AJAX (Asynchronous JavaScript and XML), including:
- AJAX allows web pages to be updated asynchronously by exchanging data with a server in the background without reloading the entire page.
- It uses a combination of XMLHttpRequest object, JavaScript, DOM, and often XML to retrieve data from the server and update parts of the page.
- The XMLHttpRequest object handles asynchronous requests in the background. Readystatechange events and response properties are used to update page elements with the server response.
- Common AJAX techniques like GET and POST requests, callbacks, and examples are explained.
Ajax allows web pages to asynchronously update parts of a page by exchanging data with a web server behind the scenes, without reloading the entire page. It uses a combination of technologies including HTML, JavaScript, CSS, and XML/XHTML to retrieve data from the server and update parts of the page. This allows pages to load faster and provides a more responsive interface compared to full page reloads.
The document explains what AJAX is and how it works. AJAX stands for Asynchronous JavaScript and XML and allows a client browser to communicate asynchronously with a web server via JavaScript and XMLHttpRequest. It allows updating parts of a web page without reloading the entire page. The document provides a visualization of a typical AJAX process where a user clicks a button triggering an AJAX call, a request is sent to the server, the server returns requested data to the browser which is then used to update specific parts of the DOM without reloading the whole page. It also includes an example of a basic AJAX program with explanation of how it works.
AJAX is a set of web development techniques used to create interactive web applications. It allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes, without interfering with the display and behavior of the existing page. This is done through JavaScript and the XMLHttpRequest object, allowing new information to be added without reloading the entire page. Common uses of AJAX include updating parts of a web page without reloading, autocomplete functions, and real-time notifications.
This document provides an overview of AJAX (Asynchronous JavaScript and XML). It begins with defining AJAX and its advantages over traditional web applications. It then discusses the AJAX acronym in more detail. Next, it compares the traditional web application model to the AJAX model. It explains how AJAX uses asynchronous requests to update parts of a web page without reloading the entire page. The document then covers the basic working of AJAX, including initializing the XMLHttpRequest object, opening a connection, defining handlers, sending requests, and receiving responses. It provides an example of asynchronous data transfer using AJAX with client-side and server-side code. Finally, it lists some references for further information on AJAX.
Similar to Computers & Technology :: Extracting Data from an AJAX-enabled Web Site (20)
Computers & Technology :: Extracting Data from an AJAX-enabled Web Site
1. Computers & Technology :: Extracting Data from an AJAX-
enabled Web Site
AJAX is the what makes web sites interactive. It stands for Asynchronous JavaScript and XML. Based
on the xmlHttpRequest function, it allows the website to contact the server and retrieve data
(referred to as an "AJAX Callback") without reloading the web page. In one simplified example, it
stops that flicker when you hit the "Submit" button, giving the website a more streamlined feel.
Because of this, web sites have gotten complicated and web mining has as well. Visual Web Ripper is
still able to work through this process, although code navigation is necessary.
How To
Before starting, you must tell Visual Web Ripper the changes that will occur on the website. To keep
data from being extracted prematurely, VWR will need to wait for the callback to finish.
To have a successful template when working with AJAX, go to Options and click the AJAX or
JavaScript radio button. If necessary, use the Wait for element drop down box to select the proper
element, otherwise the default Wait Element will the first content element in the template.
VWR will render AJAX in three steps, unless told otherwise
1.Clicks on the selected link or web form button
2.Waits for the Wait Element and/or its container to change. This step will be completed
automatically if the content doesn't exist.
3.Waits for the Wait Element to appear on the web page.
Troubleshooting:
A lot of web sites use transition words to tell users that content is being loaded (e.g. "Loading...").
VWR will assume this is the change and extract that as data. To counter this, utilize a Wait Script.
Sometimes an AJAX callback will result in no change either to the entire web page or to the content
that preloads. If either of these scenarios arises, click the appropriate checkbox(es): Wait is optional
and/or Optional wait applies only to the first link in a list.
All AJAX is JavaScript, but not all JavaScript is AJAX. If the code doesn't dynamically change content,
it is simple JavaScript and thus the Wait is optional and/or Optional wait applies only to the first link
in a list boxes need to be checked.
VWR is all-seeing, including hidden content, so no separate AJAX action template is necessary.
Switch to browser mode to find what you need.
AJAX was built for content that appears after a page rendering. In this scenario, go to Options, click
Misc, and check Wait for element.
Iframes are tricky, since they look like AJAX callbacks to VWR. Use the Keep loading webpage until
manual stop button on the toolbar to work around this issue.
2. Though AJAX sites can present hurdles when doing web mining, combining a powerful extraction
tool such as Visual Web Ripper with the knowledge of how to navigate through it puts the target
data within reach.