Code example provided by user for sending emails with PDF attachments from Salesforce.com using Sendgrid API v2

gistfile1.txt

global class SendGrid {
  private static final String ENCODING = 'UTF-8';
  private static final String API_URL = 'https://api.sendgrid.com/api/mail.send.json';
  
  private transient String username;
  private transient String password;
  private transient String apikey;
  private enum AUTHTYPE {KEY, USER_PASS}
  private AUTHTYPE selAuthType;
 
  private List<string> tos = new List<String>();

  public SendGrid(String username, String password) {
    this.username = username;
    this.password = password;
    this.apikey = null;
    selAuthType = AUTHTYPE.USER_PASS;
  }

  public SendGrid(String apiKey) {
    this.apikey = apikey;
	this.apikey = '12345766';

    selAuthType = AUTHTYPE.KEY;
  }

  public String credentialsToWebFormat() {
    String output = '';

    if(selAuthType == AUTHTYPE.USER_PASS) {
      output += 'api_user=' + this.username; 
      output += '&api_key=' + this.password;
    }

    return output;
  }

  public void sendTrigger(SendGrid.Email email) {
    verifyAuthentication();

    String body = this.credentialsToWebFormat() + email.toWebFormat();

    Map<String, String> sgHeaders = new Map<String, String>{
      'Content-Type' => 'application/x-www-form-urlencoded',
      'Content-Length' => String.valueof(body.length())
    };

    //HTTPCalloutHandler.HTTPCalloutFuture(API_URL, 'POST', body, sgHeaders, apiKey);
  }

  public SendGridResponse send(SendGrid.Email email) {

    verifyAuthentication();

    String messageBoundry = generateMessageBoundry();

    String body = email.toMultipartFormat(messageBoundry);

    Blob bodyBlob = EncodingUtil.base64Decode(body);

    Map<String, String> sgHeaders = new Map<String, String>{
      'Content-Type' => 'multipart/form-data;boundary="'+messageBoundry+'"',
      'Content-Length' => String.valueof(body.length())
    };
    //return null;
    HTTPResult res = HTTPCalloutHandler.HTTPCallout(API_URL, 'POST', bodyBlob, sgHeaders, apiKey);
    if(res.success) {
      return new SendGridResponse(res.statusCode, res.body);
    } else {
      throw new SendGridException(res.status);
    }

   /*HttpRequest req = new HttpRequest();
    Http http = new Http();

    req.setEndpoint(API_URL);
    req.setMethod('POST');
    req.setHeader('Content-Type','');
    req.setBody(body);
    req.setHeader('Content-Length',String.valueof(body.length()));

    try {
      HttpResponse res = http.send(req);
      return new SendGridResponse(res.getStatusCode(), res.getBody());
    } catch (Exception e) {
      throw new SendGridException(e);
    }*/
  }

  private String generateMessageBoundry() {
      String hashString = '1000' + String.valueOf(Datetime.now().formatGMT('yyyy-MM-dd HH:mm:ss.SSS'));
      Blob hash = Crypto.generateDigest('MD5', Blob.valueOf(hashString));
      String hexString = EncodingUtil.convertToHex(hash);
      return '----------------------------'+hexString;
    }

  global class Email {
    public Smtpapi.Header smtpapi;

    public String fromm;
    public String fromname;
    public String replyto;
    public List<String> bcc = new List<String>();
    public String subject;
    public String text;
    public String html;
    public Map<String, String> headers = new Map<String, String>();
    public Map<String, String> toEmailName = new Map<String, String>();
    public Map<String, Blob> files = new Map<String, Blob>();


    public Email() {
      this.smtpapi = new Smtpapi.Header();
    }

    public Email addTo(String toEmail) {
      return addTo(toEmail, toEmail);
    }

    public Email addTo(String toEmail, String toName) {
      this.smtpapi.addTo(toEmail);
      this.toEmailName.put(toEmail, toName);
      return this;
    }

    public Email setTos(List<String> tos) {
      this.smtpapi.setTos(tos);
      return this;
    }

    public Email setFrom(String email) {
      this.fromm = email;
      return this;
    }

    public Email setFromName(String name) {
      this.fromname = name;
      return this;
    }

    public Email setReplyTo(String email) {
      this.replyto = email;
      return this;
    }

    public Email addBcc(String email) {
      this.bcc.add(email);
      return this;
    }

    public Email setSubject(String subject) {
      this.subject = subject;
      return this;
    }

    public Email setText(String text) {
      this.text = text;
      return this;
    }

    public Email setHtml(String html) {
      this.html = html;
      return this;
    }

    public Email addSubstitution(String key, List<String> val) {
      this.smtpapi.addSubstitution(key, val);
      return this;
    }

    public Email addUniqueArg(String key, String val) {
      this.smtpapi.addUniqueArg(key, val);
      return this;
    }

    public Email addCategory(String category) {
      this.smtpapi.addCategory(category);
      return this;
    }

    public Email addSection(String key, String val) {
      this.smtpapi.addSection(key, val);
      return this;
    }

    public Email addFilter(String filter_name, String parameter_name, String parameter_value) {
      this.smtpapi.addFilter(filter_name, parameter_name, parameter_value);
      return this;
    }

    public Email addHeader(String key, String val) {
      this.headers.put(key, val);
      return this;
    }

    public Email addAttachmentStream(String filename, String content) {
      this.files.put(filename, Blob.valueOf(content));
      return this;
    }

    public Email addAttachmentStream(String filename, Blob content) {
      this.files.put(filename, content);
      return this;
    }

    public String toWebFormat() {
      String output = '';

      // updateMissingTo - There needs to be at least 1 to address, 
      // or else the mail won't send.
      if (!this.smtpapi.to.isEmpty() && !String.isBlank(this.fromm)) {
        for(String t :this.smtpapi.to) {
          String encoded = EncodingUtil.urlEncode(t, ENCODING);
          output += '&to[]=' + encoded;
        }        
      }

      if (!String.isBlank(this.fromm)) {
        String encoded = EncodingUtil.urlEncode(this.fromm, ENCODING);
        output += '&from=' + encoded;
      }

      if (!String.isBlank(this.fromname)) {
        String encoded = EncodingUtil.urlEncode(this.fromname, ENCODING);
        output += '&fromname=' + encoded;
      }

      if (!String.isBlank(this.replyto)) {
        String encoded = EncodingUtil.urlEncode(this.replyto, ENCODING);
        output += '&replyto=' + encoded;
      }

      if (!this.bcc.isEmpty()) {
        for (String bcc_email : this.bcc) {
          String encoded = EncodingUtil.urlEncode(bcc_email, ENCODING);
          output += '&bcc[]=' + encoded;
        }
      }

      if (!String.isBlank(this.subject)) {
        String encoded = EncodingUtil.urlEncode(this.subject, ENCODING);
        output += '&subject=' + encoded;
      }

      if (!String.isBlank(this.text)) {
        String encoded = EncodingUtil.urlEncode(this.text, ENCODING);
        output += '&text=' + encoded;
      }

      if (!String.isBlank(this.html)) {
        String encoded = EncodingUtil.urlEncode(this.html, ENCODING);
        output += '&html=' + encoded;
      }


      if (this.smtpapi.jsonString() != '{}') {
        String encoded = EncodingUtil.urlEncode(this.smtpapi.jsonString(), ENCODING);
        output += '&x-smtpapi=' + encoded;
      }

      if (!this.headers.isEmpty()) {
        String serialized_headers = JSON.serialize(this.headers);
        String encoded = EncodingUtil.urlEncode(serialized_headers, ENCODING);
        output += '&headers=' + encoded;
      }

      /*if (!this.files.isEmpty()) {
        for (String filename : this.files.keySet()){
          String value = this.files.get(filename);
          String encoded = EncodingUtil.urlEncode(value, ENCODING);
          output += '&files['+filename+']=' + encoded;
        }
      }*/

      return output;
    }

    //Allows attaching Binary files
    private String toMultipartFormat(String boundry) {

      String header = '';

      if (!this.smtpapi.to.isEmpty() && !String.isBlank(this.fromm)) {
        for(String t :this.smtpapi.to) {
          header += getPartString('to[]',t, boundry);
          header += getPartString('toname[]',this.toEmailName.get(t), boundry);
        }  
      }

      if (!String.isBlank(this.fromm)) {
        header += getPartString('from',this.fromm, boundry);
      }

      if (!String.isBlank(this.fromname)) {
        header += getPartString('fromname',this.fromname, boundry);
      }

      if (!String.isBlank(this.replyto)) {
        header += getPartString('replyto',this.replyto, boundry);
      }

      if (!this.bcc.isEmpty()) {
        for (String bcc_email : this.bcc) {
          header += getPartString('bcc[]',bcc_email, boundry);
        }
      }

      if (!String.isBlank(this.subject)) {
        header += getPartString('subject',this.subject, boundry);
      }

      if (!String.isBlank(this.text)) {
        header += getPartString('text',this.text, boundry);
      }

      if (!String.isBlank(this.html)) {
        header += getPartString('html',this.html, boundry);
      }


      if (this.smtpapi.jsonString() != '{}') {
        //header += getPartString('x-smtpapi',this.smtpapi.jsonString(), boundry);
      }

      if (!this.headers.isEmpty()) {
        String serialized_headers = JSON.serialize(this.headers);
        header += getPartString('headers',serialized_headers, boundry);
      }

      String footer = '--'+boundry+'--';

      String encodedBody = '';

      String headerEncoded = EncodingUtil.base64Encode(Blob.valueOf(header+'\r\n\r\n'));
      while(headerEncoded.endsWith('=')) {
        header += ' ';
        headerEncoded = EncodingUtil.base64Encode(Blob.valueOf(header+'\r\n\r\n'));
      }

      if (!this.files.isEmpty()) {
        encodedBody = headerEncoded + encodeWithAttachments(footer, boundry, this.files);
      } else {
        encodedBody = headerEncoded + EncodingUtil.base64Encode(Blob.valueOf('\r\n' + footer)); 
      }

      return encodedBody;
    }

    private String encodeWithAttachments(String footer, String boundry, Map<String, Blob> atts) {
      String attachmentsStr = '';
      String lastPrepend = '';
      for(String fileName :atts.keySet()) {
        Blob fileBlob = atts.get(fileName);
        String fHeader = lastPrepend + '--'+boundry+'\r\n';
        fHeader += 'Content-Disposition: form-data; name="files['+fileName+']"; filename="'+fileName+'"\r\nContent-Type: application/octet-stream';
        String fHeaderEncoded = EncodingUtil.base64Encode(Blob.valueOf(fheader+'\r\n\r\n'));
        while(fHeaderEncoded.endsWith('=')) {
          fHeader += ' ';
          fHeaderEncoded = EncodingUtil.base64Encode(Blob.valueOf(fHeader+'\r\n\r\n'));
        }
        String fbodyEncoded = EncodingUtil.base64Encode(fileBlob);
        String last4Bytes = fbodyEncoded.substring(fbodyEncoded.length()-4,fbodyEncoded.length());
        if(last4Bytes.endsWith('==')) {
          last4Bytes = last4Bytes.substring(0,2) + '0K';
          fBodyEncoded = fbodyEncoded.substring(0,fbodyEncoded.length()-4) + last4Bytes;
          lastPrepend = '';
        } else if(last4Bytes.endsWith('=')) {
          last4Bytes = last4Bytes.substring(0,3) + 'N';
          fBodyEncoded = fbodyEncoded.substring(0,fbodyEncoded.length()-4) + last4Bytes;
          lastPrepend = '\n';
        } else {
          lastPrepend = '\r\n';
        }
        attachmentsStr += fHeaderEncoded + fBodyEncoded;
      }
      footer = lastPrepend + footer;

      return attachmentsStr + EncodingUtil.base64Encode(Blob.valueOf(footer)); 
    }

    private String getPartString(String valType, String val, String boundry) {
      String part = '';
      part += '--'+boundry+'\r\n';
      part += 'Content-Disposition: form-data; name="'+valType+'"\r\n\r\n'+val+'\r\n';
      return part;
    }

  }

  

  private void verifyAuthentication() {
    
    if(this.selAuthType == AUTHTYPE.USER_PASS && (this.username == null || this.password == null)) {
      throw new SendGridException('Username and Password Missing');
    }

    if(this.selAuthType == AUTHTYPE.KEY && this.apikey == null) {
      throw new SendGridException('API Key is missing');
    }

  }

  public class SendGridException extends Exception {}

  public class SendGridResponse {
    public Integer code { get; private set; }
    public Boolean success { get; private set; }
    public String message { get; private set; }

    public SendGridResponse(Integer code, String body) {
      this.code = code;
      this.success = code == 200;
      this.message = body;
    }
  }
}