Parsing CSV Values In To A ColdFusion Query

<cffunction
	name="CSVToQuery"
	access="public"
	returntype="query"
	output="false"
	hint="Converts the given CSV string to a query.">

	<!--- Define arguments. --->
	<cfargument
		name="CSV"
		type="string"
		required="true"
		hint="This is the CSV string that will be manipulated."
		/>

	<cfargument
		name="Delimiter"
		type="string"
		required="false"
		default=","
		hint="This is the delimiter that will separate the fields within the CSV value."
		/>

	<cfargument
		name="Qualifier"
		type="string"
		required="false"
		default=""""
		hint="This is the qualifier that will wrap around fields that have special characters embeded."
		/>


	<!--- Define the local scope. --->
	<cfset var LOCAL = StructNew() />


	<!---
		When accepting delimiters, we only want to use the first
		character that we were passed. This is different than
		standard ColdFusion, but I am trying to make this as
		easy as possible.
	--->
	<cfset ARGUMENTS.Delimiter = Left( ARGUMENTS.Delimiter, 1 ) />

	<!---
		When accepting the qualifier, we only want to accept the
		first character returned. Is is possible that there is
		no qualifier being used. In that case, we can just store
		the empty string (leave as-is).
	--->
	<cfif Len( ARGUMENTS.Qualifier )>

		<cfset ARGUMENTS.Qualifier = Left( ARGUMENTS.Qualifier, 1 ) />

	</cfif>


	<!---
		Set a variable to handle the new line. This will be the
		character that acts as the record delimiter.
	--->
	<cfset LOCAL.LineDelimiter = Chr( 10 ) />


	<!---
		We want to standardize the line breaks in our CSV value.
		A "line break" might be a return followed by a feed or
		just a line feed. We want to standardize it so that it
		is just a line feed. That way, it is easy to check
		for later (and it is a single character which makes our
		life 1000 times nicer).
	--->
	<cfset ARGUMENTS.CSV = ARGUMENTS.CSV.ReplaceAll(
		"\r?\n",
		LOCAL.LineDelimiter
		) />


	<!---
		Let's get an array of delimiters. We will need this when
		we are going throuth the tokens and building up field
		values. To do this, we are going to strip out all
		characters that are NOT delimiters and then get the
		character array of the string. This should put each
		delimiter at it's own index.
	--->
	<cfset LOCAL.Delimiters = ARGUMENTS.CSV.ReplaceAll(
		"[^\#ARGUMENTS.Delimiter#\#LOCAL.LineDelimiter#]+",
		""
		)

		<!---
			Get character array of delimiters. This will put
			each found delimiter in its own index (that should
			correspond to the tokens).
		--->
		.ToCharArray()
		/>


	<!---
		Add a blank space to the beginning of every theoretical
		field. This will help in make sure that ColdFusion /
		Java does not skip over any fields simply because they
		do not have a value. We just have to be sure to strip
		out this space later on.

		First, add a space to the beginning of the string.
	--->
	<cfset ARGUMENTS.CSV = (" " & ARGUMENTS.CSV) />

	<!--- Now add the space to each field. --->
	<cfset ARGUMENTS.CSV = ARGUMENTS.CSV.ReplaceAll(
		"([\#ARGUMENTS.Delimiter#\#LOCAL.LineDelimiter#]{1})",
		"$1 "
		) />


	<!---
		Break the CSV value up into raw tokens. Going forward,
		some of these tokens may be merged, but doing it this
		way will help us iterate over them. When splitting the
		string, add a space to each token first to ensure that
		the split works properly.

		BE CAREFUL! Splitting a string into an array using the
		Java String::Split method does not create a COLDFUSION
		ARRAY. You cannot alter this array once it has been
		created. It can merely be referenced (read only).

		We are splitting the CSV value based on the BOTH the
		field delimiter and the line delimiter. We will handle
		this later as we build values (this is why we created
		the array of delimiters above).
	--->
	<cfset LOCAL.Tokens = ARGUMENTS.CSV.Split(
		"[\#ARGUMENTS.Delimiter#\#LOCAL.LineDelimiter#]{1}"
		) />


	<!---
		Set up the default records array. This will be a full
		array of arrays, but for now, just create the parent
		array with no indexes.
	--->
	<cfset LOCAL.Rows = ArrayNew( 1 ) />

	<!---
		Create a new active row. Even if we don't end up adding
		any values to this row, it is going to make our lives
		more smiple to have it in existence.
	--->
	<cfset ArrayAppend(
		LOCAL.Rows,
		ArrayNew( 1 )
		) />

	<!---
		Set up the row index. THis is the row to which we are
		actively adding value.
	--->
	<cfset LOCAL.RowIndex = 1 />


	<!---
		Set the default flag for wether or not we are in the
		middle of building a value across raw tokens.
	--->
	<cfset LOCAL.IsInValue = false />


	<!---
		Loop over the raw tokens to start building values. We
		have no sense of any row delimiters yet. Those will
		have to be checked for as we are building up each value.
	--->
	<cfloop
		index="LOCAL.TokenIndex"
		from="1"
		to="#ArrayLen( LOCAL.Tokens )#"
		step="1">


		<!---
			Get the current field index. This is the current
			index of the array to which we might be appending
			values (for a multi-token value).
		--->
		<cfset LOCAL.FieldIndex = ArrayLen(
			LOCAL.Rows[ LOCAL.RowIndex ]
			) />

		<!---
			Get the next token. Trim off the first character
			which is the empty string that we added to ensure
			proper splitting.
		--->
		<cfset LOCAL.Token = LOCAL.Tokens[ LOCAL.TokenIndex ].ReplaceFirst(
			"^.{1}",
			""
			) />


		<!---
			Check to see if we have a field qualifier. If we do,
			then we might have to build the value across
			multiple fields. If we do not, then the raw tokens
			should line up perfectly with the real tokens.
		--->
		<cfif Len( ARGUMENTS.Qualifier )>


			<!---
				Check to see if we are currently building a
				field value that has been split up among
				different delimiters.
			--->
			<cfif LOCAL.IsInValue>


				<!---
					ASSERT: Since we are in the middle of
					building up a value across tokens, we can
					assume that our parent FOR loop has already
					executed at least once. Therefore, we can
					assume that we have a previous token value
					ALREADY in the row value array and that we
					have access to a previous delimiter (in
					our delimiter array).
				--->

				<!---
					Since we are in the middle of building a
					value, we replace out double qualifiers with
					a constant. We don't care about the first
					qualifier as it can ONLY be an escaped
					qualifier (not a field qualifier).
				--->
				<cfset LOCAL.Token = LOCAL.Token.ReplaceAll(
					"\#ARGUMENTS.Qualifier#{2}",
					"{QUALIFIER}"
					) />


				<!---
					Add the token to the value we are building.
					While this is not easy to read, add it
					directly to the results array as this will
					allow us to forget about it later. Be sure
					to add the PREVIOUS delimiter since it is
					actually an embedded delimiter character
					(part of the whole field value).
				--->
				<cfset LOCAL.Rows[ LOCAL.RowIndex ][ LOCAL.FieldIndex ] = (
					LOCAL.Rows[ LOCAL.RowIndex ][ LOCAL.FieldIndex ] &
					LOCAL.Delimiters[ LOCAL.TokenIndex - 1 ] &
					LOCAL.Token
					) />


				<!---
					Now that we have removed the possibly
					escaped qualifiers, let's check to see if
					this field is ending a multi-token
					qualified value (its last character is a
					field qualifier).
				--->
				<cfif (Right( LOCAL.Token, 1 ) EQ ARGUMENTS.Qualifier)>

					<!---
						Wooohoo! We have reached the end of a
						qualified value. We can complete this
						value and move onto the next field.
						Remove the trailing quote.

						Remember, we have already added to token
						to the results array so we must now
						manipulate the results array directly.
						Any changes made to LOCAL.Token at this
						point will not affect the results.
					--->
					<cfset LOCAL.Rows[ LOCAL.RowIndex ][ LOCAL.FieldIndex ] = LOCAL.Rows[ LOCAL.RowIndex ][ LOCAL.FieldIndex ].ReplaceFirst( ".{1}$", "" ) />

					<!---
						Set the flag to indicate that we are no
						longer building a field value across
						tokens.
					--->
					<cfset LOCAL.IsInValue = false />

				</cfif>


			<cfelse>


				<!---
					We are NOT in the middle of building a field
					value which means that we have to be careful
					of a few special token cases:

					1. The field is qualified on both ends.
					2. The field is qualified on the start end.
				--->

				<!---
					Check to see if the beginning of the field
					is qualified. If that is the case then either
					this field is starting a multi-token value OR
					this field has a completely qualified value.
				--->
				<cfif (Left( LOCAL.Token, 1 ) EQ ARGUMENTS.Qualifier)>


					<!---
						Delete the first character of the token.
						This is the field qualifier and we do
						NOT want to include it in the final value.
					--->
					<cfset LOCAL.Token = LOCAL.Token.ReplaceFirst(
						"^.{1}",
						""
						) />

					<!---
						Remove all double qualifiers so that we
						can test to see if the field has a
						closing qualifier.
					--->
					<cfset LOCAL.Token = LOCAL.Token.ReplaceAll(
						"\#ARGUMENTS.Qualifier#{2}",
						"{QUALIFIER}"
						) />

					<!---
						Check to see if this field is a
						self-closer. If the first character is a
						qualifier (already established) and the
						last character is also a qualifier (what
						we are about to test for), then this
						token is a fully qualified value.
					--->
					<cfif (Right( LOCAL.Token, 1 ) EQ ARGUMENTS.Qualifier)>

						<!---
							This token is fully qualified.
							Remove the end field qualifier and
							append it to the row data.
						--->
						<cfset ArrayAppend(
							LOCAL.Rows[ LOCAL.RowIndex ],
							LOCAL.Token.ReplaceFirst(
								".{1}$",
								""
								)
							) />

					<cfelse>

						<!---
							This token is not fully qualified
							(but the first character was a
							qualifier). We are buildling a value
							up across differen tokens. Set the
							flag for building the value.
						--->
						<cfset LOCAL.IsInValue = true />

						<!--- Add this token to the row. --->
						<cfset ArrayAppend(
							LOCAL.Rows[ LOCAL.RowIndex ],
							LOCAL.Token
							) />

					</cfif>


				<cfelse>


					<!---
						We are not dealing with a qualified
						field (even though we are using field
						qualifiers). Just add this token value
						as the next value in the row.
					--->
					<cfset ArrayAppend(
						LOCAL.Rows[ LOCAL.RowIndex ],
						LOCAL.Token
						) />


				</cfif>


			</cfif>


			<!---
				As a sort of catch-all, let's remove that
				{QUALIFIER} constant that we may have thrown
				into a field value. Do NOT use the FieldIndex
				value as this might be a corrupt value at
				this point in the token iteration.
			--->
			<cfset LOCAL.Rows[ LOCAL.RowIndex ][ ArrayLen( LOCAL.Rows[ LOCAL.RowIndex ] ) ] = Replace(
				LOCAL.Rows[ LOCAL.RowIndex ][ ArrayLen( LOCAL.Rows[ LOCAL.RowIndex ] ) ],
				"{QUALIFIER}",
				ARGUMENTS.Qualifier,
				"ALL"
				) />


		<cfelse>


			<!---
				Since we don't have a qualifier, just use the
				current raw token as the actual value. We are
				NOT going to have to worry about building values
				across tokens.
			--->
			<cfset ArrayAppend(
				LOCAL.Rows[ LOCAL.RowIndex ],
				LOCAL.Token
				) />


		</cfif>



		<!---
			Check to see if we have a next delimiter and if we
			do, is it going to start a new row? Be cautious that
			we are NOT in the middle of building a value. If we
			are building a value then the line delimiter is an
			embedded value and should not percipitate a new row.
		--->
		<cfif (
			(NOT LOCAL.IsInValue) AND
			(LOCAL.TokenIndex LT ArrayLen( LOCAL.Tokens )) AND
			(LOCAL.Delimiters[ LOCAL.TokenIndex ] EQ LOCAL.LineDelimiter)
			)>

			<!---
				The next token is indicating that we are about
				start a new row. Add a new array to the parent
				and increment the row counter.
			--->
			<cfset ArrayAppend(
				LOCAL.Rows,
				ArrayNew( 1 )
				) />

			<!--- Increment row index to point to next row. --->
			<cfset LOCAL.RowIndex = (LOCAL.RowIndex + 1) />

		</cfif>

	</cfloop>


	<!---
		ASSERT: At this point, we have parsed the CSV into an
		array of arrays (LOCAL.Rows). Now, we can take that
		array of arrays and convert it into a query.
	--->


	<!---
		To create a query that fits this array of arrays, we
		need to figure out the max length for each row as
		well as the number of records.

		The number of records is easy - it's the length of the
		array. The max field count per row is not that easy. We
		will have to iterate over each row to find the max.

		However, this works to our advantage as we can use that
		array iteration as an opportunity to build up a single
		array of empty string that we will use to pre-populate
		the query.
	--->

	<!--- Set the initial max field count. --->
	<cfset LOCAL.MaxFieldCount = 0 />

	<!---
		Set up the array of empty values. As we iterate over
		the rows, we are going to add an empty value to this
		for each record (not field) that we find.
	--->
	<cfset LOCAL.EmptyArray = ArrayNew( 1 ) />


	<!--- Loop over the records array. --->
	<cfloop
		index="LOCAL.RowIndex"
		from="1"
		to="#ArrayLen( LOCAL.Rows )#"
		step="1">

		<!--- Get the max rows encountered so far. --->
		<cfset LOCAL.MaxFieldCount = Max(
			LOCAL.MaxFieldCount,
			ArrayLen(
				LOCAL.Rows[ LOCAL.RowIndex ]
				)
			) />

		<!--- Add an empty value to the empty array. --->
		<cfset ArrayAppend(
			LOCAL.EmptyArray,
			""
			) />

	</cfloop>


	<!---
		ASSERT: At this point, LOCAL.MaxFieldCount should hold
		the number of fields in the widest row. Additionally,
		the LOCAL.EmptyArray should have the same number of
		indexes as the row array - each index containing an
		empty string.
	--->


	<!---
		Now, let's pre-populate the query with empty strings. We
		are going to create the query as all VARCHAR data
		fields, starting off with blank. Then we will override
		these values shortly.
	--->
	<cfset LOCAL.Query = QueryNew( "" ) />

	<!---
		Loop over the max number of fields and create a column
		for each records.
	--->
	<cfloop
		index="LOCAL.FieldIndex"
		from="1"
		to="#LOCAL.MaxFieldCount#"
		step="1">

		<!---
			Add a new query column. By using QueryAddColumn()
			rather than QueryAddRow() we are able to leverage
			ColdFusion's ability to add row values in bulk
			based on an array of values. Since we are going to
			pre-populate the query with empty values, we can
			just send in the EmptyArray we built previously.
		--->
		<cfset QueryAddColumn(
			LOCAL.Query,
			"COLUMN_#LOCAL.FieldIndex#",
			"CF_SQL_VARCHAR",
			LOCAL.EmptyArray
			) />

	</cfloop>


	<!---
		ASSERT: At this point, our return query LOCAL.Query
		contains enough columns and rows to handle all the
		data that we have stored in our array of arrays.
	--->


	<!---
		Loop over the array to populate the query with
		actual data. We are going to have to loop over
		each row and then each field.
	--->
	<cfloop
		index="LOCAL.RowIndex"
		from="1"
		to="#ArrayLen( LOCAL.Rows )#"
		step="1">

		<!--- Loop over the fields in this record. --->
		<cfloop
			index="LOCAL.FieldIndex"
			from="1"
			to="#ArrayLen( LOCAL.Rows[ LOCAL.RowIndex ] )#"
			step="1">

			<!---
				Update the query cell. Remember to cast string
				to make sure that the underlying Java data
				works properly.
			--->
			<cfset LOCAL.Query[ "COLUMN_#LOCAL.FieldIndex#" ][ LOCAL.RowIndex ] = JavaCast(
				"string",
				LOCAL.Rows[ LOCAL.RowIndex ][ LOCAL.FieldIndex ]
				) />

		</cfloop>

	</cfloop>


	<!---
		Our query has been successfully populated.
		Now, return it.
	--->
	<cfreturn LOCAL.Query />

</cffunction>

<!---
	Build the CSV string value. This value should contain
	both functional and character-literal delimiters.
--->
<cfsavecontent variable="strCSV">
Name,Nickname,Best Asset
Sarah,"""Stubbs""",Butt
Ashley,"Value with
embedded line break",Smile
Heather
"Kat",",",
</cfsavecontent>

<!---
	Send the CSV value to the UDF. Be sure to trim the value
	(leading and trailing spaces). We are going to leave the
	default delimiter (,) and qualifier (").
--->
<cfset qResult = CSVToQuery(
	CSV = strCSV.Trim()
	) />

<!--- Dump out the resultant query. --->
<cfdump
	var="#qResult#"
	label="CSV Results Query"
	/>