Wednesday, April 29, 2009

Cold Fusion interview questions


Describe about string encryption?

CFML language provides a 32 bit encryption which is symmetric key based. This function is called as Encrypt. Cold fusion at present uses 32 bit encryption but if your application requires 1024 bit encryption you can happily use that function because cold fusion integrates with third party libraries. Cold fusion also uses Hash function which is very important in safeguarding passwords. They use MD5 and XOR based algorithm.

What is cold fusion component roles implementation?

Cold fusion component roles implementation allows users to log into their role based administrator support function and not any other function. If a user tries to enter into other functions an error is thrown. These roles and components are taken by the Cold fusion. These roles and functions are transmitted through action script which allows the users to work on their components.

What is CFCHART engine?

This CFCHART provides more than 200 different attributes which can be altered and these attributes can be used to control animation, labels, and colors. This CFCHART engine is used to produce high quality graphs, charts, sketches, and these charts can also aid you in Business analysis. These charts aid you very much in developing a good business presentation as you can control every part of it.

Which tag aids us in Debugging and attribute in inter site scripting attack?

The tag which aids you in debugging is cftimer tag; this tag gives you the exact time which happens between executions of each line of code. cfapplication helps you prevent intersite scripting attack.

Explain about enterprise manager?

Enterprise manager helps you in admin functions. This will help you to create multiple cf server instances, through which you can experience advanced security, performance, and savings.

What is the benefit of extensible gateway architecture?

Developers can benefit from extensible gateways by limitless variety of emerging protocols. Developers can benefit by the creation of event gateways.

What are the different types of resources through which cold fusion can communicate?

(i) Mobile phones that support SMS

(ii) XMPP or Lotus IM clients

(iii) Java sockets

(iv) Java messaging service

(v) Content management systems and file systems



What are the two primary types of files in a cold fusion application?

There are two primary types of file systems in ColdFusion which are used extensively they are Coldfusion templates and coldfusion pages. Developers in addition to these use CFML. These can contain HTML and often CFML for Dynamic content.

State and explain about integrating Coldfusion applications with JSP.

A cold fusion page can contain JSP or a servlet and a JSP page can contain Coldfusion applications. This facilitates easy access to build hybrid functions and applications which can combine coldfusion components and servlets.

Should I use the and tags?

If you can, absolutely, there is no reason not to. But be aware that these tags do have significant limitations - they only work with FORM fields, they require that the FORM fields be named the same as the table columns, you cannot do any processing or manipulation of the values, and when updating the row primary key must be present as a FORM field (possibly as a hidden field).

Is it possible to generate an e-mail message with both text and HTML versions in the same message?

This is possible as of ColdFusion MX 6.1 via the new tag. The following code snippet demonstrates the use of this new tag:







This is the text version.








This is the HTML version.








How can I obtain the date, time, or size of a file?

is used for directory access and manipulation. ACTION="list" returns the date, time, size, and file attributes.

Can ColdFusion determine the user that a client is logged in as?

Developers would love to be able to dynamically determine client workstation login information so as to use this for access control within their own applications. Unfortunately, this information is not available to server side technologies like ColdFusion (if it were, that would present an enormous security risk). The only way to get this information is to have some application running on the client (maybe a Java applet or an ActiveX control, for example) and have it return this information to you.

How do I create a form to be used for file uploading?

You need to set create a form, set the

ENCTYPE attribute to "multiform/form-data", and then add a form field of TYPE="file". When the form is displayed it will contain a field and button for file selection, and when the form is submitted the file will be uploaded to ColdFusion. An example of this is shown below:



ENCTYPE="multipart/form-data"


METHOD="post">


File:









What is the REQUEST scope?

REQUEST is similar to VARIABLES in that it is tied to a single request only and contents persist only for the duration of page processing. The difference between REQUEST and VARIABLES is that REQUEST is also visible to other files being processed in the REQUEST, like Custom Tags.

How can I obtain the list of columns in a retrieved query?

Every query contains a member named columnlist which can be accessed as query.columnlist.

How can I obtain the list of any received FORM fields or URL parameters?

URL and FORM are ColdFusion structures, and may be used as any other ColdFusion structures. For example, contents may be dumped, members may be accessed directly, and can be used to loop through URL or FORM members.



How can I directly access specific query data?

For direct access to specific query rows and columns, access them as if they were structures and arrays. You can refer to a specific column of a specific row as #query.column[row]#. For example, if you wanted the "price" column for the fifth row of a query named "products" you could use the expression #products.price[5]#. This technique is especially useful when looping through query results to perform some processing.



How can I generate printable PDF output using ColdFusion?

PDF generation is supported as of ColdFusion MX 7 using the new tag.

When and why are quotes needed in SQL statements?

All content in between and is sent to the database via the database driver as is. Unlike CFML, SQL is not typeless, and so SQL statements must be complete and valid as per SQL syntax specifications. All strings (or variables being used as string values) must be enclosed within singe quotes. Similarly, all numeric values must not be within quotes, and all dates and times must be formatted as valid date and time values.

What exactly is ColdFusion ?

Cold fusion is the only software which helps the programmer to develop dynamic websites with backend database. ColdFusion is the only website which helps in developing dynamic websites. This is useful in software development. This has an application server and software development framework which greatly aid in developing computer software.

Describe in detail about programming details in ColdFusion?

ColdFusion differs from major languages such as JSP, ASP.NET or PHP due to its associated scripting language and ColdFusion markup language. The syntax closely resembles to HTML. This language supports server side Action script and embedded scripts which can be written in ColdFusion script. This script is used for data driven websites. This technology also supports languages such as Flex which is used for client side scripting. This has many interfaces embedded in it which allows for services such as SMS and instant messaging.

Explain about some of the features present in ColdFusion MX7?

This edition from adobe was named as Macromedia ColdFusion MX7. Some of the features which are present are web forms, Xforms, adobe acrobat friendly report builder, flash, excel and rich text format style. This edition of cold fusion provided Gateways which helped in connecting various services such as IM, SMS, etc.

Is it possible to write cold fusion in cold fusion?

No it is not possible to write ColdFusion in ColdFusion. Actually ColdFusion was written in Java and to write programs we need to implement other kinds of programs such as Java, .NET etc. These programs are required because ColdFusion alone cannot survive.

Can we modify ColdFusion server code and what are the two open source CFML parsing engines?

Server code of ColdFusion cannot be viewed or modified. The language of ColdFusion itself is documented and subjected to rights laid down by adobe. The two open source engines which are parsing ColdFusion’s markup languages are Blue dragon and Smith project. Blue dragon is a J2EE version.

What are the benefits of multiple server instances?

The benefits of multiple server instances are, a single server is enough to deploy a host of applications which makes it highly applicable this was not the case when MX7 was present. Applications running on a server need not be stopped for maintenance as the work and load is shared upon multiple servers. Security, optimized applications and clustering are some of the main benefits of Adobe cold fusion multiple server instances.

Describe about Clustering

In previous installations of Adobe cold fusion multiple servers were required to run the application but adobe cold fusion 8 mitigated the problem by clustering Coldfusion into multiple physical installations which take over the load if any application fails during its course of time. This also allows in easy maintenance and possible reduction in maintaining multiple servers. This was made possible by J2EE server.

Submitted 2008-07-27 23:32:16

What is the function of CFDIRECTORY in Coldfusion?

is used for directory access and manipulation. Using ACTION="list" we can get date,time,size and file attributes.

Is it possible to nest CFML conditional tags?

yes, CFML conditional and flo-control tags like ans can be nested. but deep nesting may impact performance.

Yes, this is possible for example:















What is the extension with which the CFML gets saved in files?

it is .cfm

Why is CFML not a real programming language? What are the causes for this?

It IS a real programming language. These days it also supports Object-oriented development with Mach-II, Fusebox etc.

Is there a way for a file to know it's own file name?

There are a few ways: cgi.script_name refers to both the path and file name, so if your file was in a folder under the webroot called stuff, and was named foo.cfm, the value of cgi.script_name would be /stuff/foo.cfm. Another cgi variables, cgi.cf_template_path, represents the complete path of the current file. You can also call the CF function, getCurrentTemplatePath. If you only want the file name from these two values, use the getFileFromPath function.

When using comma delimited ColdFusion lists, why are empty elements ignored?

ColdFusion lists are not CSV comma-delimited lists and do not behave as CSV lists do. ColdFusion ignores empty list elements, so ListLen("a,b,,d,e") will return 4 (not 5), and ListGetAt("a,b,,d,e", 5) will throw an error. To convert a ColdFusion list to a CSV list, use Replace() and replace all ",," (comma comma) with ", ," (comma space comma) - a space is a valid list member value and ColdFusion will not ignore it.

Describe about the level of security a firm can have while running adobe cold fusion?

Cold fusion 8 has enhanced security features, it provides multiple adobe cold fusion installations on the server which necessarily removes the threat of accidental deletion, intrusion, addition, etc because the remote lies with multiple administrators and they can set permissions and access. Data sources, Cold fusion components and custom tags can be differentiated on their work accordingly.

How one can provide secured internet applications using adobe ColdFusion?

The three major internet security threats are

1) Memory leak during transmit of information

2) Impersonation which is like an exact clone which enters as legitimate

3) Unauthorized access

These mechanisms are handled by adobe by using Data encryption, User Authentication and Access control.

Explain about ColdFusion administrator?

ColdFusion administrator is a web based application just like the Cpanel this has many sub options through which you can control many functions such as data sources, global server settings, debugging settings, and application security settings. If you are having multiple administrator services then password must be provided for all those services. Also multiple user instances are provided where by a server can be split into cluster of Coldfusion administrators where a specific work can be provided to a specific individual who cannot alter changes.

Is there any facility which prevents viewing of source code?

ColdFusion has a utility called cfencode which blocks viewing of the source code on coldfusion pages which has an application. Although guarantee of this product is not guaranteed, to an extent this can block viewing of source code altogether. As ColdFusion runs on a web server source code can be blocked completely.

CF Database Query

Explain Query of Query Concept?

Creating such Database Query/Queries that uses the existing query's output as input without accessing the database tables



for example:



db query reference : #existing query name.ID or name ... #





use or to check the output of existing query, used for the new query.

How can you create connections between your ColdFusion Web sites and databases?

I will use DSN. These are set up in CF administrator and used in query code to connect to a database.

Where can one view the value of the Proxy Port in Coldfusion Administrator?

The Proxy Port, which is not the "Remote Port" mentioned in the ColdFusion Administrator, can only be viewed in the Jrun Administrator, which should running on your "master" Jrun4 server on port 8000. (ie http://my.master.node:8000)

What is used to mount the web root locally to the Coldfusion instance?

ColdFusion ought to have the webroot mounted locally if it is running on a other machine from the web server(s). We have always use NFS to mount the web root locally to the ColdFusion instance. There have also been some reveal of mirroring the web root to the ColdFusion machine, but that would only work if there was little development on a site, as there would be latency between files on the live site, and those on the ColdFusion server.

What is used to duplicate sessions between instances in Coldfusion clusters?

What can be used to make easy data transfer to the coldfusion server?

cfqueries can be used

Does Coldfusion support client and session variables? If not give the reason for the same?

Yes it supports both .

What databases are supported by ColdFusion applications?

All relational and non relational databases like Oracle, MSAccess, mysql

What happens when the read properties of the ColdFusion server to a file is withdrawn?

How can I loop through URL or FORM members in Coldfusion?

You can use

Which function of coldfusion is used for getting the value out of a dynamically named variable?

A variable can be declared dynamically and evaluated using the function EVALUATE()

List the lock types supported by ?

supports 2 different types of lock, EXCLUSIVE and READONLY. An EXCLUSIVE lock stop access by any other code and READONLY is more of a flag that marks a block of code that will only be executed if there is no active EXCLUSIVE lock.

How can I control concurrent access to a block of code or a scope in coldfusion?

You can use to block a piece of code.

cfapplication can also be used.

By which mean I can transfer files between a client browser and ColdFusion?

The safest way to transfer files from a client computer to coldfusion is to use Http file upload.

What is the cause for using ColdFusion only on the server side. Can Coldfusion be used in the client side?

coldfusion is used on server side mostly because of safety reasons only. But it can be used in client side too

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