Server-side processing

Once a questionnaire has been designed and created, it is necessary to make it available online and add a means of collecting and processing the results. Doing this successfully requires the addition of server-side processes.

This page is designed to provide you with an overview of server-side processing technologies. It will explain what server-side processing is and how it can be used to collect data from questionnaires. It will cover the following areas:

• The nature of server-side processing and how it differs from client-side processing;
• How server-side and client side processing interact when a questionnaire is requested and submitted;
• An overview of the options for hosting the questionnaire on a server, which will be needed to make the questionnaire available online;
• An introduction to some of the key technologies required and the options available:
  • Server software: Apache and Microsoft;
  • Server-side processing software: CGI, ASP.NET, PHP, ColdFusion and JSP;
  • Database software: MySQL and SQL Server;
• How to set up a test-server on a personal computer to use when developing using these technologies;
• An overview of how WYSIWYG web editors and other software can be used to help with the development;
• An outline of common server-side processing tasks that are carried out to process a questionnaire;
• Links to key resources on each of the server-side processing technologies.

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To understand how server-side processing works and how it differs from client-side processing, it is useful to firstly consider what happens when a user successfully calls a web page. The main steps can be seen as follows:

1. The user types the URL of the webpage into the browser's location bar or clicks on a link. This URL acts as a reference to the computer on which the webpage is held (the server) and the location of the file (its name and position inside the file tree).
2. The browser sends a message over the internet to the server computer requesting the webpage.
3. Server software (e.g. Apache) on the server computer receives the message.
4. The URL is correct and up-to-date, and there are no problems with the server computer, so the software is able to locate the file in the computer's hard drive.
5. The software sends a copy of the file back to the browser on the requesting computer (the client).
6. The browser displays the page according to the HTML and CSS instructions it contains.
7. Alternatively, if there is a problem with the server or the URL is incorrect, an error message is displayed by the browser on the client machine.

This can be shown diagrammatically as follows:

The files held on the server are 'static' which means that all users who request the webpage will be delivered exactly the same content from the hard drive. It cannot be altered unless the developer makes a change to the files and saves them again.

The way that client-side and server-side processing works inside the interaction between client and server can be seen below. This is followed by an overview of the advantages and disadvantages of each.

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In delivering, receiving and processing a questionnaire, the main steps in the interaction between server and client are typically as follows (a text-only version is available below):

Both server and client-side processing are used to process the questionnaire. Client-side processing is used for validation as it will provide improved usability and speed to those who have JavaScript available on their computers, but will not reduce accessibility for those who do not. Server-side processing is used to deal with the results and also to provide 'back-up' validation where JavaScript is unavailable or where users may have deactivated it to avoid validation.

The following learning activities will allow you to examine this process of delivering, receiving and processing a questionnaire in more detail:

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A number of technologies are available to add server-side processing functionalities to web pages, but whichever technology is chosen, the questionnaire will need to be uploaded to a server along with the required databases and/or scripts. The choice of which technology to use is likely to depend primarily on the type of server and software available and the level of access the researcher has to this server.

The following three hosting options are likely to be available to researchers who wish to create and upload their own questionnaires:

When choosing a hosting option, it is important to consider the URL the questionnaire will have when it is made publicly available. It may be necessary to choose and acquire a specific domain name for the questionnaire. Information about domain names is provided below.

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The server software handles requests for webpages from the server and also handles the interaction with server-side processing technologies and databases. In many cases, the choice of which server-side technology can be used depends on the server software that is installed. This, in turn, often depends on which operating system is in use on the computer (e.g. windows or linux). The most popular server software in use on the internet is Apache which is a free open-source option which can be used on both operating systems. Microsoft server software is also a commonly-used example, available for use on the Windows operating system and other server software is also available. Most hosts are likely to use one of these two options, though other server software is available. It is likely to be important to find out which operating system and server software are used, so that the researcher can set up a similar development environment on a personal computer to create and test the questionnaire before uploading it. Where a researcher wishes to use a particular type of software this will also be a key consideration when choosing a hosting service.

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A number of technologies are available to allow server-side processing to be added to web pages. Some of the technologies are open-source and freely available for both development on a local computer and for use with servers to host public websites. The proprietary technologies are frequently also available free of charge as 'development' versions which can only be run on local machines. However, they can be expensive to buy where they are to be used with servers to host open websites. Where a researcher wishes to use this software, it will be necessary to check that it is available on the hosting server.

It is necessary to find out which operating system and server software is used by the host, and to find out which server-side processing technologies are supported. This will allow the decision on which technology to use to develop the questionnaire to be made. Where a researcher wishes to use a particular technology, it will also allow a hosting service offering this technology to be chosen. Commonly-used examples of server-side processing technologies are introduced below, and links to the official websites for each are also given.

The 'Resources' section below contains references and links to introductory information and tutorials on the use of these technologies, and to resources on the use of these technologies to perform common questionnaire processing tasks.

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Where the intention is to use server-side processing technology in combination with databases it will be necessary to choose an appropriate example of database software. As with the server-side technology, a major influence on this choice is likely to be the type of database available on the hosting server, though where a researcher wishes to use a particular type of software, this will be one of the key issues in selecting a service provider.

A wide range of database software is available that can be integrated with server-side processing. The high-end databases such as Oracle, Informix or Sybase may be a suitable solution for complex research projects with adequate funds available for the purchase. However, in most cases, the two most common options are likely to be Microsoft's SQL server for use with ASP.NET, or MySQL for use with the other server-side technologies and with PHP in particular.

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Once it has been established what technologies are to be used, it is possible to download, install and configure the software needed to develop and test the questionnaire. This process will be different depending on the technologies chosen, but will typically involve the following stages:

1. Download/purchase and install the server software, following the installation instructions provided.
2. Test that the server is working correctly on the local machine. Some server software (e.g. Apache) will include a test page with the download. This will be saved in the root of the directory used by the server to hold the webpages which it will deliver. In the case of Apache, this will typically be the htdocs directory in the Apache program files on the hard drive (e.g. C:\Program Files\Apache Group\Apache2\htdocs). If no test page is available with a particular server, or if the researcher wishes to carry out a further test, an alternative test page (e.g. an HTML page with a name such as 'testing.html') can also be created and saved in this directory. The URL can then be typed into a web browser to view the page. This is typically 'http://localhost/'when the server is running on a local machine (e.g. 'http://localhost/testing.html'). If the installation has been successful, the test page will be displayed.
3. Download/purchase the server-side processing and database technologies to a suitable directory (e.g. if installing PHP, this should be downloaded to a file called php on the root of the hard drive).
4. Configure the server software, the server-side processing technology and the database software to allow them to work together. This can be quite a complex process requiring settings and/or configuration files to be altered, and it is important to refer to up-to-date guidance (see below).
5. Create a test database and a test page including a connection to this database. Save this in the root directory used by the server and access it through the browser to check that the page is displayed successfully, indicating that the software is interacting correctly (see point 2).

When carrying out this process, it is important to refer to detailed and up-to-date guidance specific to the particular technologies used. Most training books on particular software will include a step-by-step guide to installation and configuration on different platforms (see the 'Resources' section below). When choosing a book, it is important to check that this information is provided for the software versions and platform you wish to use. Guides are also available on the internet.

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A number of tools are available to assist in the development web pages with server-side processing capabilities. The use of WYSIWYG web editors can simplify and automate many of the common tasks involved in producing a questionnaire processed server-side, such as validation routines or connecting to databases, and other tools are available to help with the creation of scripts or the administration of databases.

Macromedia Dreamweaver is a commonly-used WYSIWYG editor which offers support to users who are developing server-processed webpages. Through Dreamweaver, it is possible to set up an environment for developing pages using all of the most common server-side technologies including those mentioned above. Once this is done, tools are available within the package to allow functionalities to be automatically added such as database connections, validation or password access. If the user has a knowledge of the chosen technology and wishes to create different functionalities, tools such as tag choosers can also provide assistance with coding in the chosen language.

Microsoft FrontPage is another WYSIWYG editor which allows the development of features such as validation of form data client and server-side, sending form results to an MS Access database or connecting to an alternative external database. This can be done with little or no knowledge of server-side processing using dialogue boxes within the editor. However, taking advantage of this requires that the server the questionnaire will be hosted on allows the use of FrontPage extensions, a proprietary Microsoft technology. If you have a knowledge of the editor and a server which allows this, however, it can dramatically simplify the process and reduce the need to spend time learning about new technologies or developing programming skills.

Where ASP.NET is the chosen technology for implementing the questionnaire, development tools such as the Microsoft Visual Web Developer are available to provide a drag-and-drop interface for page creation and to simplify the creation of code and integration with databases. The free WYSIWYG Web Matrix software is also available from Microsoft for the development of these pages.

Finally, a number of tools are available to make the production of PHP code and the creation and administration of MySQL databases easier and more intuitive. Like PHP and MySQL, these tools tend to be available open source and can be found by searching open-source repositories (See the 'Resources' section for example of these repositories).

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Once the software and technologies used have been established, and the development environment has been set up accordingly, the pages and scripts can be developed to add server-side processing facilities to the questionnaire. In some cases, if a questionnaire has already been developed, it may be necessary to adapt the HTML to suit the server technology used. Thus, for example, if ASP.NET is used, the HTML form elements may need to be replaced with the ready-made web controls available with this technology.

Common server-side processing tasks are as follows:

• Validation, which should be added as a back-up to client-side validation. Facilities also need to be added to send a thank-you message on submission where no problems are found, or for the questionnaire to be redisplayed when errors are found (this should be done so that error messages highlight the problem, while the answers a participant has already entered are preserved);
• Emailing results, which may be the preferred method of processing the results as it is straightforward and easy to implement. The emails can also be encrypted to increase the security of sensitive data. Where a database is used, the researcher may also wish for the results to be emailed at the same time as they are added to the database.
• Automatically adding submitted data to a database, so that responses are added to the database on submission of the form;
• Adding a system of password access, so that only invited participants with access to a password can access the questionnaire and so that multiple submission using the same password is prevented;
• Working with multi-page forms, to pass the information gathered from page to page, or to submit each page when it is completed and then prevent participants going back and resubmitting these pages.

A wide range of books are available on the use of server-side processing technologies, along with websites offering tutorials and scripts. A number of suggestions for each of the main technologies is provided in the 'Resources' section below. This includes links to useful sources of information, tutorials and examples on how the common questionnaire processing tasks outlined above can be developed using these technologies.

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