Welcome!

Adobe Flex Authors: Matthew Lobas, PR.com Newswire, Shelly Palmer, Kevin Benedict

Related Topics: Adobe Flex

Adobe Flex: Article

CSV in Flash MX 2004

Make your classes easy and flexible

CSV is a format that has been around for a long time. It's a simple way to store multiple rows with multiple columns and it can be easily imported into a variety of commonly used desktop applications. This article examines the use of CSV-formatted data in Flash. We will write a class in ActionScript 2.0 to handle all of our CSV functionality and then we will use this class to populate the Macromedia v2 Data Grid Component.

Why Use a CSV File?
CSV is a very simple format. At its core it is essentially a large string that has rows separated by a delimiter and columns within each row delimited by a comma. Because of its use of rows and columns, this data format is perfectly suited for record sets, whereas an XML-formatted record set is more complicated.

Another good reason to use CSV is that it can be viewed by many common desktop applications. Any spreadsheet program, such as Microsoft Excel, can view, modify, or create CSV files. Unlike an XML-formatted record set, users can open a CSV file and easily read the information.

Like XML, CSV is data formatted within a file. It's not tied to any specific software or platform and it doesn't need a server in order to deliver it to the client. This makes CSV and XML files a very portable way to handle data. You could build a Web- based Flash application using a CSV or XML file and then easily use that same code to build a CD-ROM-based application.

CSV will not always be the right solution for your project. XML is usually a better solution for delivering data to the client because of its versatility. Any time your data is not formatted in a series of rows and columns, CSV should be avoided. You should also refrain from using the CSV format if you have multiple levels of complex data types. For example, if you have an array or a list in one of your cells, you should probably use XML to define your data. XML is better at separating out different data types and handling multiple levels of embedded data. CSV should only be used for primitive data types (String, Number, and Boolean) that are housed in the row-and-column format.

CSV Specifications
The first thing you'll notice about a CSV file is that it has rows and columns. The rows are delimited by a line break, a carriage return, or a combination of the two. The columns within each row are separated by a comma. Many times the first row of the file is used to define the column headers; we'll talk more about that when we begin parsing the data in our custom class.

Many CSV files will use something called a qualifier, the most common qualifier being the double quote ("). This character is used to surround each column's data. Below you can see the difference between a file with a qualifier and one without a qualifier.

CSV data without a qualifier:
Field 1,Field 2,Field 3,Field 4
Field 5,Field 6,Field 7,Field 8

CSV data with a qualifier:
"Field 1","Field 2","Field 3","Field 4"
"Field 5","Field 6","Field 7","Field 8"

Building the CSV Class
Before we begin programming our CSV class, we need to define exactly what we need this class to do:

  1. The class will need to load in an external CSV file.
  2. The class will need to parse the data into a Flash object. The format we want to get the CSV data into would be an array of objects (or associative arrays), with the object's key being the column header.
  3. The parsing will need to be able to pull the column headers from the first row of the CSV; however, we will also want to give the user the option to override this feature by specifically defining the columns in an array prior to parsing the file.
  4. We also need the parser to be able to handle qualifiers. We will allow the user to define the qualifier prior to parsing the CSV data.
We'll start our class by defining it. Our class won't be using the constructor for anything, so we can leave that method empty.


class CSV {
	function CSV() {}
}

Next we need to define our class's parameters:

  • csvData is a private array that will hold the parsed CSV data.
  • onLoad is a public method that the user can overwrite to get a callback when the data is loaded and parsed.
  • columns is a public array that the user can define prior to parsing the CSV data to manually define the column headers.
  • qualifier is a public string that the user can define prior to parsing the CSV data. Qualifiers assist with more accurate parsing. We will default this value to an empty string.


private var csvData:Array;
public var onLoad:Function;
public var columns:Array;
public var qualifier:String = '';

The first task that we need our class to do is load data in from a file. We'll accomplish this by creating a load method, which will simply take in the CSV file's path as its only parameter. The load method will use the LoadVars class to load the file into Flash, but we will actually incorporate an undocumented method within the LoadVars class, called onData. This method works exactly like the XML.onData method. It allows us to get the raw file data without having it parsed by the LoadVars class.


public function load(csvPath:String):Void {
	var csvLoad:LoadVars = new LoadVars();
	csvLoad._parent = this;
	csvLoad.onData = function(rawData:String) {
		this._parent.onData(rawData);
	}
	csvLoad.load(csvPath);
}

Notice that in our LoadVars.onData method we are calling a method within our class, called onData. We will create that method to handle the parsing of the CSV data after the file has loaded. Once the data is parsed it will pass it back to the user through the onLoad method. We won't actually define the onLoad method. To handle the load method callback, the user will define this method. Users could also override the onData method if they didn't want the data parsed right away.


public function onData(rawData:String):Void {
	csvData = parseCSV(rawData);
	onLoad();
}

Next we'll add the parser method. We'll make this method public so users can utilize it without loading in the CSV data from a file. The parser is the most complicated part of this class - it is also the part of the class where the most can go wrong.

Our parser method will take a raw CSV string as its sole parameter and return the parsed data as an array of objects. The first two things our parser method must do is determine the row and column delimiters. We already know that the row delimiter is a carriage return (\r), a new line (\n), or both (\r\n). A quick search of the string will help us determine what the actual row delimiter is. The column delimiter is always a comma in the CSV specification; however, we can make our parsing more accurate by adding the qualifier before and after the delimiter. This new concatenated string will be our column delimiter.

To begin parsing the CSV string we will split the string into an array of its rows. This will allow us to loop through the rows and parse each row individually.

If the column's parameter has not been defined prior to running this parser method, then we can assume the first row in the CSV file holds the column headings. We will populate the column's array from this row.

As we loop through the rows we will split each row into an array of its columns. If the row doesn't have the same number of columns as the columns parameter, then we will skip that row. As we loop through the columns within each row we will place the data into an object using the column heading as the key. We will then append this object to the end of the array that we will be returning (see Code I).

We also need to create a private method called removeQualifier that supports the parser. This method will pull out the qualifier at the beginning and end of each row (see Code II).

In order to expose the private csvData parameter, we will create a getter method called data. This method will simply return the parsed data to the user. We do this to protect the csvData parameter from being set outside the class.


public function get data():Array {
	return csvData;
}

Using the CSV Class with the Data Grid Component
In this example we will use Macromedia's Data Grid Component to display our CSV data. The data grid's dataProvider parameter accepts an array of objects as a valid value, so we won't have to manually populate the grid. The first thing we need to do is place an instance of the data grid on the stage, then give it an instance name of dataGrid_mc. Then we will create a new layer and name it Actions. We will put all of our code in frame 1 of the Actions layer. Make sure your CSV.as class file is in the same folder as your FLA file.

In frame 1 of our Actions layer we will begin writing our code, creating an instance of the CSV class.


var csvLoad:CSV = new CSV();

Next we define our columns and qualifier parameters before we parse the CSV file.


csvLoad.columns = new Array('Column 1', 'Column 2', 'Column 3');
csvLoad.qualifier = '"';

We then define our onLoad method, where we populate the data grid with the parsed CSV data. Finally, we call the load method and send it the path to our CSV file as an argument.


csvLoad.onLoad = function() {
	dataGrid_mc.dataProvider = this.data;
}
csvLoad.load('sampleData.csv');

Conclusion
I hope this article gives you an idea of how you can use CSV data within your Flash application. But more important, I hope it has given you a concrete example of how you can build an ActionScript 2.0 class and how you can make your class easy and flexible to the developers that implement it. This CSV class may not be the solution for your application, but the principles of object-oriented programming should be used in nearly every application you build with Flash.

Note: Class code can be downloaded from www.sys-con.com/mx/sourcec.cfm.

More Stories By Danny Patterson

Danny Patterson is a Consultant
specializing in Flash and Web technologies. Danny is a Partner and
Author at Community MX (communitymx.com) and a member of Team Macromedia
Flash. He is a Certified Advanced ColdFusion MX, Flash MX and Flash MX
2004 Developer. You can check out his weblog at DannyPatterson.com.

Comments (5) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
kalavati 05/27/09 07:31:00 AM EDT

According to my current requirement I want to know is there simple Flex compatible parser for use in parsing CSV (comma separated value) format files. This may already be available in Flex Builder. If not what is the best way to parse these files.

kalavati 05/27/09 01:17:00 AM EDT

According to my current requirement I want to know is there simple Flex compatible parser for use in parsing CSV (comma separated value) format files. This may already be available in Flex Builder. If not what is the best way to parse these files.

Raul Justiniano 07/25/07 06:52:20 PM EDT

The link: www.sys-con.com/mx/sourcec.cfm. in this blog entry is not a available on the server. It is supposed to be a link to download the class.

Abel 07/25/07 11:05:29 AM EDT

Link to cownload the class not available.

Nermeen Elhelw 06/13/06 07:50:03 AM EDT

so u managed to load data from csv file,

i want to make the user write a word then hit search, and flash searches a certain field in the .csv file and have it display the other fields that are related to the search term

do u know how to do that?????

please help

@ThingsExpo Stories
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
SYS-CON Events announced today that Datera, that offers a radically new data management architecture, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datera is transforming the traditional datacenter model through modern cloud simplicity. The technology industry is at another major inflection point. The rise of mobile, the Internet of Things, data storage and Big...
While the focus and objectives of IoT initiatives are many and diverse, they all share a few common attributes, and one of those is the network. Commonly, that network includes the Internet, over which there isn't any real control for performance and availability. Or is there? The current state of the art for Big Data analytics, as applied to network telemetry, offers new opportunities for improving and assuring operational integrity. In his session at @ThingsExpo, Jim Frey, Vice President of S...
DX World EXPO, LLC., a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
"We provide IoT solutions. We provide the most compatible solutions for many applications. Our solutions are industry agnostic and also protocol agnostic," explained Richard Han, Head of Sales and Marketing and Engineering at Systena America, in this SYS-CON.tv interview at @ThingsExpo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"We are focused on SAP running in the clouds, to make this super easy because we believe in the tremendous value of those powerful worlds - SAP and the cloud," explained Frank Stienhans, CTO of Ocean9, Inc., in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"DX encompasses the continuing technology revolution, and is addressing society's most important issues throughout the entire $78 trillion 21st-century global economy," said Roger Strukhoff, Conference Chair. "DX World Expo has organized these issues along 10 tracks with more than 150 of the world's top speakers coming to Istanbul to help change the world."
"We've been engaging with a lot of customers including Panasonic, we've been involved with Cisco and now we're working with the U.S. government - the Department of Homeland Security," explained Peter Jung, Chief Product Officer at Pulzze Systems, in this SYS-CON.tv interview at @ThingsExpo, held June 6-8, 2017, at the Javits Center in New York City, NY.
With tough new regulations coming to Europe on data privacy in May 2018, Calligo will explain why in reality the effect is global and transforms how you consider critical data. EU GDPR fundamentally rewrites the rules for cloud, Big Data and IoT. In his session at 21st Cloud Expo, Adam Ryan, Vice President and General Manager EMEA at Calligo, will examine the regulations and provide insight on how it affects technology, challenges the established rules and will usher in new levels of diligence...
The financial services market is one of the most data-driven industries in the world, yet it’s bogged down by legacy CPU technologies that simply can’t keep up with the task of querying and visualizing billions of records. In his session at 20th Cloud Expo, Karthik Lalithraj, a Principal Solutions Architect at Kinetica, discussed how the advent of advanced in-database analytics on the GPU makes it possible to run sophisticated data science workloads on the same database that is housing the rich...
SYS-CON Events announced today that Massive Networks will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Massive Networks mission is simple. To help your business operate seamlessly with fast, reliable, and secure internet and network solutions. Improve your customer's experience with outstanding connections to your cloud.
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
"The Striim platform is a full end-to-end streaming integration and analytics platform that is middleware that covers a lot of different use cases," explained Steve Wilkes, Founder and CTO at Striim, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
SYS-CON Events announced today that Calligo, an innovative cloud service provider offering mid-sized companies the highest levels of data privacy and security, has been named "Bronze Sponsor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Calligo offers unparalleled application performance guarantees, commercial flexibility and a personalised support service from its globally located cloud plat...
Everything run by electricity will eventually be connected to the Internet. Get ahead of the Internet of Things revolution and join Akvelon expert and IoT industry leader, Sergey Grebnov, in his session at @ThingsExpo, for an educational dive into the world of managing your home, workplace and all the devices they contain with the power of machine-based AI and intelligent Bot services for a completely streamlined experience.
"MobiDev is a Ukraine-based software development company. We do mobile development, and we're specialists in that. But we do full stack software development for entrepreneurs, for emerging companies, and for enterprise ventures," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
In his opening keynote at 20th Cloud Expo, Michael Maximilien, Research Scientist, Architect, and Engineer at IBM, discussed the full potential of the cloud and social data requires artificial intelligence. By mixing Cloud Foundry and the rich set of Watson services, IBM's Bluemix is the best cloud operating system for enterprises today, providing rapid development and deployment of applications that can take advantage of the rich catalog of Watson services to help drive insights from the vast t...
SYS-CON Events announced today that EnterpriseTech has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. EnterpriseTech is a professional resource for news and intelligence covering the migration of high-end technologies into the enterprise and business-IT industry, with a special focus on high-tech solutions in new product development, workload management, increased effic...
SYS-CON Events announced today that Massive Networks, that helps your business operate seamlessly with fast, reliable, and secure internet and network solutions, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. As a premier telecommunications provider, Massive Networks is headquartered out of Louisville, Colorado. With years of experience under their belt, their team of...