Update August 22nd, 2015 – Please note that this is an experiment in reading a CSV and pulling the data into Visualforce. In no way should this be part of a Production-ready solution as it DOES NOT SCALE. You will hit limits as the number of rows in the CSV increases. As a solution, this would NOT be considered a best practice.

I recently had to develop a Visualforce page that allowed a Salesforce user to upload a CSV file and then generate some records from the parsed values. Yes, I know that is what the Data Loader is for, but the intended user here was not technically adept. And I thought it was an interesting experiment.

The Salesforce Developer Wiki already had a sample class for parsing the file – http://wiki.developerforce.com/index.php/Code_Samples#Parse_a_CSV_with_APEX . So, I had to just create the VF page and my controller. Though, I did modify the parsing method from the Wiki to use the carriage return in the string split. CSV’s produced on my Mac didn’t parse correctly using the newline ‘\n’. I found a good post here explaining how Windows and Mac/Unix handle carriage returns differently. Here’s the results.

Visualforce page: uploadCSV

<apex:page controller=”uploadCSVcontroller” >
  <apex:form >
  <apex:inputFile value=”{!contentFile}” filename=”{!nameFile}” /><br/>
  <apex:commandButton value=”Upload” id=”theButton”/>
  </apex:form>
  <apex:outputPanel id=”results”>
  <p>nameFile: {!nameFile}</p>
  <p>rowCount: {!rowCount}</p>
  <p>colCount: {!colCount}</p>
    <table title=”CSV Output” border=”1″ width=”100%”>
       <apex:repeat value=”{!results}” var=”row”>
           <tr>
               <apex:repeat value=”{!row}” var=”cell”>
                   <td> {!cell} </td>
               </apex:repeat>
           </tr>
       </apex:repeat>
     </table>
  </apex:outputPanel>
</apex:page>

Apex Class:

public class uploadCSVcontroller {

    public Blob contentFile { get; set; }
    public String nameFile { get; set; }
    public Integer rowCount { get; set; }
    public Integer colCount { get; set; }

    public List<List<String>> getResults() {
        List<List<String>> parsedCSV = new List<List<String>>();
        rowCount = 0;
        colCount = 0;
        if (contentFile != null){
            String fileString = contentFile.toString();
            parsedCSV = parseCSV(fileString, false);
            rowCount = parsedCSV.size();
            for (List<String> row : parsedCSV){
                if (row.size() > colCount){
                    colCount = row.size();
                }
            }
        }
        return parsedCSV;
    }
    /*
    Credit to
    http://wiki.developerforce.com/index.php/Code_Samples#Parse_a_CSV_with_APEX
    */
    public static List<List<String>> parseCSV(String contents,Boolean skipHeaders) {
        List<List<String>> allFields = new List<List<String>>();

        // replace instances where a double quote begins a field containing a comma
        // in this case you get a double quote followed by a doubled double quote
        // do this for beginning and end of a field
        contents = contents.replaceAll(‘,”””‘,’,”DBLQT’).replaceall(‘”””,’,’DBLQT”,’);
        // now replace all remaining double quotes – we do this so that we can reconstruct
        // fields with commas inside assuming they begin and end with a double quote
        contents = contents.replaceAll(‘””‘,’DBLQT’);
        // we are not attempting to handle fields with a newline inside of them
        // so, split on newline to get the spreadsheet rows
        List<String> lines = new List<String>();
        try {
            //lines = contents.split(‘\n’); //correction: this only accomodates windows files
            lines = contents.split(‘\r’); // using carriage return accomodates windows, unix, and mac files
            //http://www.maxi-pedia.com/Line+termination+line+feed+versus+carriage+return+0d0a
        } catch (System.ListException e) {
            System.debug(‘Limits exceeded?’ + e.getMessage());
        }
        Integer num = 0;
        for(String line: lines) {
            // check for blank CSV lines (only commas)
            if (line.replaceAll(‘,’,”).trim().length() == 0) break;

            List<String> fields = line.split(‘,’); 
            List<String> cleanFields = new List<String>();
            String compositeField;
            Boolean makeCompositeField = false;
            for(String field: fields) {
                if (field.startsWith(‘”‘) && field.endsWith(‘”‘)) {
                    cleanFields.add(field.replaceAll(‘DBLQT’,'”‘));
                } else if (field.startsWith(‘”‘)) {
                    makeCompositeField = true;
                    compositeField = field;
                } else if (field.endsWith(‘”‘)) {
                    compositeField += ‘,’ + field;
                    cleanFields.add(compositeField.replaceAll(‘DBLQT’,'”‘));
                    makeCompositeField = false;
                } else if (makeCompositeField) {
                    compositeField +=  ‘,’ + field;
                } else {
                    cleanFields.add(field.replaceAll(‘DBLQT’,'”‘));
                }
            }

            allFields.add(cleanFields);
        }
        if (skipHeaders) allFields.remove(0);
        return allFields;      
    }

}