Shariff's BLOG: coldfusion

Showing posts with label coldfusion. Show all posts

Monday, October 13, 2008

poll in coldfusion

DOWNLOAD CFPOLL SOURCECODE

Have you ever wanted to have your own website poll in ColdFusion. If so, then hopefully the tuto-
rial below will allow you to finally add one. Or perhaps it will provide you with the incentive to
improve this one.

Some important poll features:

- Writes a cookie once the poll has been used so that the voter may not vote in the current poll
again.

(and is once again useable).

- Checks to see if a person tries to use their browser’s back button to make multiple votes and
informs them this is not allowed.

- Checks to see if the user made a selection when voting and informs them if they haven’t made
a selection.

- Checks to see if a user accessed the results page without hitting the ‘Vote’ button and then dis-
plays the current votes without adding a vote to the poll.

- Allows for users to view previous polls and results.

- Displays the results for all polls using a graphical bar as well as the numerical vote count (indi-
vidual and total) and vote results as percentages.

I also created an administration side to this system so the website owner can add, edit or remove
polls online. You will find more information on this towards the end of this tutorial. Of course, you
should only upload these pages to a secure area of your website so random people don’t edit your
polls ;)

This poll system has been created so that the poll question/answers or results are displayed in a
webpage’s header or footer using ColdFusion’s ‘cfinclude template’ code.
<CFAPPLICATION NAME=”Cookies”
SessionManagement=”Yes”
setDomainCookies=”Yes”
setClientCookies=”Yes”>

vote.cfm

From here on in, it gets harder. But hopefully it’ll all make sense once you get into it. The next

<cfif IsDefined(”cookie.poll”)>
<cfif “#Cookie.Poll#” is “#CurrentID.QuestionID#”>
Display the poll results
<cfelse>
Show the poll form with ‘Vote’ button
</cfif>
<cfelse>
Cookie does not exist. Show the poll form with ‘Vote’ button
</cfif>

What we check for first, is if the cookie for the poll already exists.

<cfif IsDefined(”cookie.poll”)>

Next, we check to see if the existing cookie is current. We do this by checking to see if the cookie’s
value is the same as the last (most recent) ‘QuestionID’ in the ‘Questions’ table of our database.
We do this by returning one row of ‘QuestionID’ in descending order.

<cfquery datasource=”fusionpoll” name=”CurrentID” MAXROWS=”1”>
SELECT Questions.QuestionID
FROM Questions
ORDER BY QuestionID DESC
</cfquery>

<cfif “#Cookie.Poll#” is “#CurrentID.QuestionID#”>

If the cookie is current, then the user has already voted and we display the current poll results. To
do this, we need to query the database for the current question, answers and votes.

<cfquery datasource=”fusionpoll” name=”Totals”>
SELECT Questions.Question, SUM(Answers.Votes) AS TotalVotes
FROM Questions INNER JOIN Answers
ON Questions.QuestionID=Answers.QuestionID
WHERE Questions.QuestionID=#Cookie.Poll#
GROUP BY Questions.Question



<cfquery datasource=”fusionpoll” name=”Results”>
SELECT Answers.Answer, Answers.Votes
FROM Answers
WHERE Answers.QuestionID=#Cookie.Poll#
ORDER BY Answers.AnswerID
</cfquery>

Once we have done this, we display the results using cfoutput. Below is the code I used to display
the results.

<table width=”175” border=”0” align=”center” cellpadding=”2” cellspacing=”0”>



<cfoutput query=”Totals”>
<tr>
<td><div align=”center”><strong>#Question#</strong></div></td>
</tr>
</cfoutput>



<cfoutput query=”Results”>



<cfset Percent=Round((Votes / Totals.TotalVotes) * 100)>
<tr>
<td><div align=”left”>#Answer#</div></td>
</tr>
<tr>



<td><div align=”left”><img align=”middle” src=”images/poll-graph.gif” width=”#Percent#%”
height=”5”></div></td>
</tr>
<tr>
<td><div align=”right”><em>#Votes# votes - #Percent#%</em></div></td>
</tr>
</cfoutput>



<cfoutput query=”Totals”>
<tr>
<td><div align=”right”><strong>Total:</strong><em><strong>
</strong>#Int(TotalVotes)# votes</em></div></td>
</tr>
</cfoutput>
</table>

The way you display the code is entirely up to you of course, but there are some things to take
notice of in the code above. For example:

<cfset Percent=Round((Votes / Totals.TotalVotes) * 100)>

This code sets ‘Percent’ as the percentage an individual vote has received by dividing the
‘Answers.Votes’ by the total number of votes(as defined in the previous ‘Totals’ query) and multi-
plying that number by 100. This is then used to set the width of the graphical display for the poll.

width=”#Percent#%”

In the image attributes, we have set the width of the image as the same percentage we calculated
previously. The last important note in the above code is that #Int(TotalVotes)# votes displays the
total number of votes for the current poll.

Continuing on with the vote.cfm page, the next step covers what to do if the cookie is not current.
If the cookie is not current, then the user has not yet voted in this poll and therefore needs to
view the question and answer choices with the ‘Vote’ button so they can vote. To make this possi-

database. We discover what the latest question is in the same way we did when checking to see if
the cookie was current.

<cfquery datasource=”fusionpoll” name=”Current” MAXROWS = “1”>
SELECT Questions.QuestionID
FROM Questions
ORDER BY Questions.QuestionID DESC
</cfquery>

<cfset display = #Current.QuestionID#>

<cfquery datasource=”fusionpoll” name=”Question”>
SELECT Questions.QuestionID, Questions.Question, Answers.AnswerID, Answers.Answer
FROM Questions INNER JOIN Answers
ON Questions.QuestionID = Answers.QuestionID
WHERE Questions.QuestionID = #display#
ORDER BY Answers.AnswerID
</cfquery>

The first query (’Current’) selects the latest question from the ‘Questions’ table thanks to our hav-
ing the MAXROWS set at “1” and by querying in descending order. Then we set ‘display’ as the
current question so we can select the corresponding answers from the ‘Answers’ table. All that is
required then is to display the form using the selected query output.

<form action=”results.cfm” method=”post” name=”Poll”>
<table border=”0” align=”center” cellpadding=”4” cellspacing=”0”>
<cfoutput query=”Question” group=”QuestionID”>



<input type=”hidden” name=”QuestionID” value=”#QuestionID#”>
<tr>
<td colspan=”2”><div align=”center”><strong>#Question#</strong></div></td>
</tr>



<cfoutput>

<td width=”10”><input type=”radio” name=”AnswerID” value=”#AnswerID#”></td>
<td><div align=”left”>#Answer#</div></td>
</tr>
</cfoutput>
</cfoutput>
<tr>
<td colspan=”2” align=”center”><input name=”Submit” type=”submit” value=”Vote”></td>
</tr>
<tr>
<td colspan=”2” align=”center”><div align=”center”>[<a
href=”results.cfm.QuestionID=<cfoutput>#display#</cfoutput>”>View
Poll Results</a>]
<br>
[<a href=”results.cfm”>Previous Poll Results</a>]</div></td>
</tr>
</table>
</form>

You should notice two links to results.cfm after the ‘Vote’ button in the code above. These will be
explained a little bit later.

Next, we have to check if none of the previous rules applied. What to do if the cookie did not ex-ist at all. If this is the case, then we simply use the same code as above to show the current poll
question and multiple choice answers with the ‘Vote’ button. If a cookie does not exist, the person
has not yet voted at all.

results.cfm

The next page is the results.cfm page which is where our vote.cfm page sent the form details
to. Unlike vote.cfm however, results.cfm is not placed in the header or footer of the website. The
results.cfm pageincludes the footer file (which then includes the vote.cfm page).

Shown below is a basic rundown of the layout of this page.

<cfif isDefined(’Form.QuestionID’)>

<cfif IsDefined(”cookie.poll”)>
<cfif “#Cookie.Poll#” is “#CurrentID.QuestionID#”>
Show warning for attempted multiple votes
<cfelse>
Nothing
</cfif>
</cfif>
Set Cookie, add vote to database and display the answer selected by the vote
<cfelse>
Show warning for no answer selected
</cfif>
<cfelse>
<cfif isdefined (’URL.QuestionID’)>
<cfif check.AllVotes is “0”>
Show warning for no votes in current poll
<cfelse>
Display poll results
</cfif>
<cfelse>
Show the droplist for the previous polls
</cfif>
</cfif>

The first check we must perform is to see if the page was reached by somebody using the form.
We do this by checking for ‘QuestionID’ from the votes.cfm page.

<cfif isDefined(’Form.QuestionID’)>
8

And next we check to see if the poll user made a selection when they hit the ‘Vote’ button. And we
do this by checking for ‘AnswerID’ from the votes.cfm page.

<cfif isDefined(’Form.AnswerID’)>

And the next check is to stop people from voting more than once by using their browser’s back
button. We check for the existence of a cookie.

<cfif IsDefined(”cookie.poll”)>

vote.cfm page. If it is current, we display a message telling the user they can not vote more than
once.

<cfquery datasource=”fusionpoll” name=”CurrentID” MAXROWS=”1”>
SELECT Questions.QuestionID
FROM Questions
ORDER BY QuestionID DESC
</cfquery>

<cfif “#Cookie.Poll#” is “#CurrentID.QuestionID#”>
<br>
<div align=”center”>Sorry, you can only vote once.</div>
<cfinclude template=”foot.cfm”>
<cfabort>

It is important to have the ‘cfabort’ code in this part of the webpage or else you will end up with
two footers in your page display. Once we have performed those checks, we know the cookie is
not current (or existing) so we set a new cookie.

<cfcookie name=”Poll” value=”#Form.QuestionID#” expires=”never”>

The value of the cookie is set as the ‘QuestionID’ value so that we can later tell if a cookie is
current when we add a new poll question. The cookie’s expiration is set to “never” because we
will simply update it whenever we add a new poll to our website. If you set your cookie to expire
before you set a new poll, people will be able to vote again.

Once the cookie is set and the vote has been made, we must update the ‘Answers’ table with the
new vote count. We select the current vote count from the ‘Answers’ table for the current ques-
tion and chosen answer (from vote.cfm) and then set ‘NewVotes’ as the current vote plus one new
vote. Then we update the votes where the ‘QuestionID’ and ‘AnswerID’ are the same as the ones
passed through from our vote.cfm page.

<cftransaction>

SELECT Votes
FROM Answers
WHERE QuestionID=#QuestionID# AND AnswerID=#AnswerID#
</cfquery>
<cfset NewVotes=LastVote.Votes + 1>
<cfquery datasource=”fusionpoll” name=”NewVote”>
UPDATE Answers
SET Votes=#NewVotes#
WHERE QuestionID=#QuestionID# AND AnswerID=#AnswerID#
</cfquery>
</cftransaction>

Next, we create queries so we can display the new vote count for all answers in the current poll.
Once this is done, you simply display the ‘QuestionID’ and ‘AnswerID’ to show the user how they
voted in the poll.

<cfquery datasource=”fusionpoll” name=”showanswer”>
SELECT Answers.Answer, Answers.AnswerID
FROM Answers
WHERE Answers.AnswerID = #AnswerID#
</cfquery>

<cfquery datasource=”fusionpoll” name=”showquestion”>
SELECT Questions.QuestionID, Questions.Question
FROM Questions
WHERE Questions.QuestionID = #QuestionID#
</cfquery>

However, if the user had hit the ‘Vote’ button without making a selection from the radio button list,
we would need to tell them of their mistake and not update the database with any votes.

<cfelse>



<br>
<div align=”center”>Sorry, you didn’t select anything. Please select an answer before hitting the

Next, we check to see if the page was accessed without somebody using the poll form. For exam-
ple, an option I’ve added to the poll is for a user to view the current poll votes before they vote for
themselves (this is one of the links I mentioned earlier that appears under the ‘Vote’ button of the
poll). So we must check to see if that is what they are doing.

<cfif isdefined (’URL.QuestionID’)>

However, we will get an error if nobody has voted yet when somebody tries to check for the cur-
rent results. So we have to provide an alternative for if this happens. If the total vote count for the
current question is zero, we tell the poll user that there are no current votes and ask them to be
the first person to vote.

<cfquery datasource=”fusionpoll” name=”check”>
SELECT SUM(Votes) AS AllVotes
FROM Answers
WHERE Answers.QuestionID=#URL.QuestionID#
</cfquery>

<cfif check.AllVotes is “0”>

<br>
<div align=”center”>There are currently no votes for this poll. Vote now to be the first.</div>

Otherwise we query the database and display the current results for the poll. This is done in the
same fashion as we did earlier in the vote.cfm page.

The final way for somebody to access the results.cfm page without using the form is when they
are looking for previous poll results (this is the other link I mentioned previously). We now display
the previous poll droplist which is dynamically populated by querying the database.

What we must do is query the ‘Questions’ table to look for the current poll. We then set the cur-
rent poll ‘QuestionID’ as ‘Current’. Next we query the ‘Questions’ table again looking for any ‘Ques-
tionID’ not equal to the current question and display them in a descending order. There is no need

We then dynamically populate the droplist with the questions.

<form action=”pastresults.cfm” method=”post”>
<cfquery datasource=”fusionpoll” name=”CurrentID” MAXROWS=”1”>
SELECT Questions.QuestionID
FROM Questions
ORDER BY QuestionID DESC
</cfquery>
<cfset Current=CurrentID.QuestionID>
<cfquery datasource=”fusionpoll” name=”PastPolls”>
SELECT Question, QuestionID
FROM Questions
WHERE QuestionID <> #Current#
ORDER by QuestionID DESC
</cfquery>
<select name=”QuestionID”>
<cfoutput query=”PastPolls”>
<option value=”#QuestionID#”>#Question#</option>
</cfoutput>
</select>
<input type=”submit” name=”Submit” value=”Show me”>
</form>

The form values are sent to pastresults.cfm, which like results.cfm, is its own page and not used
in the header or footer. This page then displays the results of the requested past poll in the same
way that results.cfm displayed the current poll results.

That then completes the user/voting side of the poll system.

Now we have to create the administration side of the poll system. I have used the same header
and footer system I used in my previous pages, but you do not have to for these pages to all
work. It’s just how I like to do things :)

The pages you need to create are:

polladd.cfm
polladdaction.cfm

polldeleteconfirm.cfm
polls.cfm
pollupdate.cfm
pollupdateaction.cfm

polls.cfm

The first page I would create is polls.cfm as it is the administration page that gives you access to
the pages that add, edit and delete polls. The first link you see on the page is a simple link to the
‘Add a poll’ page (polladd.cfm). The links to edit and delete polls however require some simple
ColdFusion. First we must query the database to get the ‘Question’ and ‘QuestionID’ details.

<cfquery name=”GetPolls” datasource=”fusionpoll”>
SELECT Questions.QuestionID, Questions.Question
FROM Questions
ORDER by QuestionID DESC
</cfquery>

We can then display the poll questions and offer links to the edit and delete pages where the
‘QuestionID’ is carried onto those pages.

polladd.cfm and polladdaction.cfm

The first administering page we will look at is the polladd.cfm page. This is a simple HTML page
where the question gets passed through to the polladdaction.cfm page through the formfield
‘Question’ and the answers all get passed through as the formfield ‘Answer’. It is important that
you inform whoever is creating these polls on your website that each answer is to be provided by
some predetermined dilimiter. For this tutorial, I will use the colon (:) as my dilimiter.

For example, if the poll question was Where did I find this Hip Poll System., then when creating
the answers, they would be typed out as TwoHipDudes:webWICKED:I don’t know:What poll!.!.

The tricky part of the polladdaction.cfm page is the looping of the ‘Answer’ field to make sure that
each provided answer gets added to the ‘Answers’ table with the matching ‘QuestionID’.

<cfquery name=”getLastID” datasource=”fusionpoll”>
SELECT MAX(QuestionID) as LastID

</cfquery>

<cfloop list=”#form.Answer#” index=”FormAnswer” delimiters=”:”>
<cfquery name=”InsertAnswers” datasource=”fusionpoll”>
INSERT INTO Answers(QuestionID, Answer)
VALUES(’#getLastID.LastID#’,’#FormAnswer#’)
</cfquery>
</cfloop>

The first query above shows how we get the most recent ‘QuestionID’ and then insert it with our
loop of provided answers. The second query shows how we set ‘Form.Answer’ in the loop to add
each new existence of the formfield to a new row in the ‘Answers’ table. Because each answer was
seperated by the colon (:) in the formfield in the polladd.cfm page, the polladdaction.cfm page
loops until all answers have been added to the database. This is because we have set the delimit-
ers in the cfloop code.

polldeleteconfirm.cfm and polldeleteaction.cfm

The polldeleteconfirm.cfm page simply provides the option to delete the selected question from
the database. The ‘QuestionID’ is passed on from the polls.cfm page. If you click the ‘Delete’ but-
ton then the poll is deleted by the processing page – polldeleteaction.cfm.

The poll is removed by polldeleteaction.cfm by deleting the question and corresponding answers
from both the ‘Questions’ and ‘Answers’ tables.

<cfquery name=”DeleteQuestion” datasource=”fusionpoll”>
DELETE
FROM Questions
WHERE QuestionID = #Form.QuestionID#
</cfquery>
<cfquery name=”DeleteAnswer” datasource=”fusionpoll”>

FROM Answers
WHERE QuestionID = #Form.QuestionID#
</cfquery>

pollupdate.cfm and pollupdateaction.cfm

The last function of the administration system is the editing feature. This is the trickiest part of the
administration process. Calling the answers from the ‘Answers’ table and then editing them re-
quires they be edited separately as they are in the same formfield name, but with separate values.

<cfoutput query=”GetAnswerDetails”>
<form method=”post” action=”pollupdateaction.cfm”>
<table width=”100%” border=”0” cellspacing=”0” cellpadding=”2”>
<tr>
<td width=”25%”><p><strong>Answer:</strong></p></td>
<td width=”75%”>
<input type=”text” name=”Answer” size=”40” maxlength=”50”
Value=”#GetAnswerDetails.Answer#”> <input type=”submit” name=”SubmitButton” value=”Make
the changes”>
<input type=”Hidden” name=”AnswerID” Value=”#GetAnswerDetails.AnswerID#”>
</td>
</tr>
</table>
</form>
</cfoutput>

For each answer in the corresponding poll there will be a form element created with its own sub-
mit button. So to edit an answer, you make your changes and press the corresponding ‘Make the
changes’ button. The changes are then updated when the form is sent to pollupdateaction.cfm.

Well, that’s it. Hopefully the tutorial makes sense and you are now able to add a poll to your web-
site. Make sure you check out the included working poll system that came with this tutorial and
see the poll working for a better idea of how everything works. The file you downloaded contains
everything you need to add the poll to your own site. You could use the database, edit the head-
ers and footers and have a fully operational poll onsite before you know what to do with it :)

This tutorial has been offered for free. I would however appreciate an email letting me know if u used in your project .

DOWNLOAD CFPOLL SOURCECODE

Sunday, September 14, 2008

What is a custom tag in coldfusion

What is a custom tag and why do i need it?
This is a question I get a lot when I bring up custom tags. A custom tag is a piece of code that you create and you call it from within your ColdFusion applications. Think of it as a "SNIPPLET" that you can implement at any time, anywhere in your site. What can you do with a custom tag? Well, just about anything!
In this tutorial I will demonstrate how you can use a custom tag to add a list of states (in a drop down select box) in a form.
Let's see how you call a custom tag. The easiest (and probably most used) method is: <cf_states>.
What does that mean?
Ok, you are simply telling ColdFusion to look in the same folder (as the file you are accessing to call the custom tag) or in the custom tags folder (Usually C:\CFusion\CustomTags\) for a file called: states.cfm. If it finds that file, you are saying to the server, execute it, process it and send me the results of it. So it's like an include, but with the difference that you can do other neat things! I'll explain more below.

You can pass values to the custom tag, as follows:
<cf_states DefaultState="TX"
FieldName="States">
This basically says that when executing the custom tag "states.cfm" the default state I want selected is "TX - Texas". Of course you'll have to write the code that will select the stat, but it's basically allowing you to tell the code in the "states.cfm" file that that is the default state. Let's create the actual states.cfm file so you can see how it works. Notice also that I'm passing a value called "FieldName" this will become the name of the form field that will be generated. That ay when you process the page in the end you'll know what name to reference.
(Note: Since you are specifying a variable for the custom tag called "DefaultState", within the custom tag, this variable is referenced as follows: "Attributes.DefaultState". All variables you pass when calling the tag (i.e. one="" two="") will always be referenced within the custom tag as "Attributes.[name of variable]".)


<cfif NOT IsDefined("Attributes.FieldName")>

<font color="red" size="4" face="Verdana">You did not specify a valid name for the select field!</font>
<cfabort>
</cfif>

<cfif NOT IsDefined("Attributes.DefaultState")>

<cfset Attributes.DefaultState = "AZ">
</cfif>


<cfoutput>
<select name="#Attributes.FieldName#">
<option value="AZ"<cfif Attributes.DefaultState eq "AZ"> SELECTED</CFIF>>AZ - Arizona</option>
<option value="CA"<cfif Attributes.DefaultState eq "CA"> SELECTED</CFIF>>CA - California</option>
<option value="MS"<cfif Attributes.DefaultState eq "MS"> SELECTED</CFIF>>MS - Mississippi</option>
<option value="NJ"<cfif Attributes.DefaultState eq "NJ"> SELECTED</CFIF>>NJ - New Jersey</option>
<option value="NY"<cfif Attributes.DefaultState eq "NY"> SELECTED</CFIF>>NY - New York</option>
<option value="TX"<cfif Attributes.DefaultState eq "TX"> SELECTED</CFIF>>TX - Texas</option>
</select>
</cfoutput>
OK, so what was the purpose of this custom tag? Well imagine that you are building 30 web sites for 30 different customers that all ask for users information. So now with this custom tag you can simply type in:
<cf_states DefaultState="TX"
FieldName="States">
So for customer one you created an automatic states drop down in the form on the fly.
Now say your second customer likes that the database values be written as tblflStates and the default state for this customer has to be New York. So in the "FieldName" you can no longer use "states". If you hadn't used a custom tag you'd have to recreate the file, use unnecessary space and waste time with something you could of already have had done. So for this customer so simple modify as follows:
<cf_states DefaultState="NY"
FieldName="TblflStates">
Are you starting to see the value of Custom tags? Well in short they're a way for you reuse your code easily and fast!
You can also do other neat things with them, but that's a whole other tutorial! :)
Congratulations, you now know how custom tags work!

Check for an IP Address in coldfusion

<CFIF #left(cgi.remote_addr,7)# is "192.168">

<cfelseif #left(cgi.remote_addr,7)# is not "192.168">
<CFlocation url = "http://www.yahoo.com">
</cfif>

The CFIF tag checks the left "7" digits of the incoming IP which is the cgi.remote_addr variable. If it meets the condition, the code is executed, if not and it meets the cfelseif then the page is redirected to Yahoo.com.

Pretty simple security to make sure requests only come from certain IPs.

cfscript in coldfusion

An Introduction to CFSCRIPT

We all know and love ColdFusion for its easy to use tag-based syntax. So why is there even a cfscript-style syntax? Well, there are a couple of reasons:
• some CFers are already proficient in other langauges, and may feel more comfortable writing program events in a more 'traditional' method.
• some people think that cfscript style syntax is easier to read (more straightforward).
• cfscript exectues faster than a comparable block of tag-based code (i've heard this is even more true in MX).
So what does all of this mean to you? Do you have to use cfscript? Absolutely not. But given the advanatges mentioned above (as well as the ability to more easily write User-Defined Functions in CF 5 and above), you may want to check out cfscript to see what it can do for you.

'Rules' of CFSCRIPT
• Place cfscript code within <cfscript></cfscript> tags.
• No ColdFusion tags can be used in cfscript blocks. Only ColdFusion functions.
• All lines must be terminated with a semi-colon (;).
• While CFSCRIPT shares many characteristics with other scripting languages such as JavaScript, it is still ColdFusion, which means ColdFusion rules/syntax still apply:
o Arrays start at position 1 (as opposed to 0)
o Use the EQ, NEQ, LT, GT (etc) comparison operators (as opposed to =, !=, <, >, etc)
o The ampersand (&) is the concatenation character (as opposed to the plus (+) character).
o CFSCRIPT is case-insensitive...but I always recommend trying to watch your cases in order to promote good programming habits

CFSCRIPT Syntax

Ok...that's all well and good. But what does it LOOK like? Fair enough. Let's start very simple. Setting a variable.

<cfscript>
myName = 'Charlie';
</cfscript>

Not so terrible, eh? :) You can even use CFSCRIPT to output your values:

<cfscript>
myName = 'Charlie';
writeOutput('my name is ' & myName);
</cfscript>

Excellent. You are well on your way :)

How about looping? Is there looping in CFSCRIPT? You bet your bippy there is ($5 to anyone who can tell me what a bippy is, by the way...i've always wondered).

Looping in CFSCRIPT

1. <cfscript>
2. myList = 'George,Paul,John,Ringo'; // creates the variable myList, which holds 4 names
3. for (i = 1; i LTE listLen(myList); i = i+1) {
4. writeOutput(listGetAt(myList, i) & "<br>");
5. }
6. </cfscript>

Let's go over this line by line, shall we?
(audience responds in unison, 'we shall')
Great.
1. Opening our
<cfscript>
block
2. create a variable called myList. Populate with 4 names (George,Paul,John,Ringo). You'll also notice the comment (the // and the text after it). This is a standard single-line script comment (similar in 'regular' CFML to ). You can also do a multi-line comment, such as:
/*
This is a multi-line comment.
anything within the slash/asterisk - asterisk/slash will be ignored by the CF Server
*/
3. Here's where we get just a little funky. This line is essentially the same as <cfloop from="1" to="#listLen(myList)#"index="i">, otherwise known as a 'for' loop. It's comprised of 3 parts...let's break 'em down to make this easier to decipher:
• i = 0 -- Straightforward enough. Sets a variable i equal to 0.
• i LTE listLen(myList) -- Says to continue the loop while i is less than or equal to (LTE) the length of our 'myList' list (which contains 4 elements...so the loop will iterate 4 times).
• i = i+1 -- Increment i by 1 for each iteration (in other scripting languages, you may have seen this as i++...unfortunately, cfscript does not support this notation).
Notice also, how each 'part' is separated by a semi-colon (;). Notice also the open curly-brace ({) at the end of the line. The code that will execute for each iteration of the loop is enclosed in curly braces (we close our curly brace in line 5).
4. Here's our output. As we did in our first example, we use cfscript's writeOutput() function. Nested within that function, is a straightforward listGetAt() function...with a <br> concatenated at the end, so we get 4 lines of output after our looping is finished. Again, notice that we end the line with a semi-colon (;).
5. We're now done with our code inside of the loop, so we close our curly brace.
6. Close our cfscript block and we're done!

Conditionals in CFSCRIPT

You may also want to look at how CFSCRIPT handles conditionals...otherwise known as <cfif><cfelseif><cfelse></cfif>.

Let's take a very basic example...We're going to generate a random number between 1 and 100...and determined if it's in the first quarter (between 1 and 25), second quarter (between 26 and 50), third quarter (between 51 and 75), or fourth quarter (between 76 and 100).

1. <cfscript>
2. myRandomNumber = randRange(1,100);
3. if (myRandomNumber GTE 1 AND myRandomNumber LTE 25) {
4. writeOutput(myRandomNumber & ' is in the first quarter');
5. } else if (myRandomNumber GTE 26 AND myRandomNumber LTE 50) {
6. writeOutput(myRandomNumber & ' is in the second quarter');
7. } else if (myRandomNumber GTE 51 AND myRandomNumber LTE 76) {
8. writeOutput(myRandomNumber & ' is in the third quarter');
9. } else {
10. writeOutput(myRandomNumber & ' is in the fourth quarter');
11. }
12. </cfscript>

...and the obligatory breakdown :)
1. Opening our <cfscript> block
2. Using ColdFusion's randRange() function, we generate a random number between 1 and 100...assinging that value to the variable myRandomNumber.
3. Our first condition. Checks to see if the value of myRandomNumber is between 1 and 25 (inclusive). This uses standard ColdFusion comparsion operators GTE and LTE for 'greater-than-or-equal-to' and 'less-than-or-equal-to'. We end the line with a curly brace...as with our loop example above, any code within the curly braces will appear if this condition is met (curly braces are not mandatory if there is only one line of code to execute in the condition...however, I include them here to show syntactically correct structure).
4. This is code that will execute if the condition in line 3 (above) is met. A simple writeOutput() (which you're familiar with by now) showing the actual value of the variable myRandomNumber, and concatenated with a string literal to show that the number is in quarter one.
5. If the previous condition is not met, we specify another condition (checking for the second quarter, or values between 26 and 50 (inclusive)). The logic is the same as in the first condition. The difference to note is the else if. This is different than ColdFusion's tag-based <cfelse>, which is one word.
6. The code to execute if the condition in line 5 (above) is met. Same as line 4.
7. See line 5 :)
8. See line 6 :)
9. Our final condition. We can use a simple else as opposed to the else if. If none of the previous 3 conditions are met, this is the only one left...as such, we do not have to specify 'if myRandomNumber GTE 76 AND myRandomNumber LTE 100', as it is implicit.
10. See line 6 :)
11. Close our one open curly brace.
12. Close our cfscript block and we're done!

That's about all for this lesson. There's much more that you can do with CFSCRIPT that I did not cover here. In addition to FOR loops, you can do CONDITIONAL loops and DO WHILE loops. For conditional processing, you can also use SWITCH/CASE statements instead of (or in addition to) the conditional example above.

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