Dave Russell » .Net

Converting HTML to PDF using EvoPdf

Dave — Thu, 14 Apr 2011 07:14:47 +0000

We have been using ABCpdf to generate PDFs on the fly of the page currently being browsed. It has given us years of service, but now with the new version of our site I have had to find an alternative solution as my page body gets styled out of sight and then moved into position using jquery to change the left:-2000px to left:0px;. ABCpdf ignores javascript so I am getting a lovely half generated page in the PDF output.

The only product I have found out there on the interwebs that understands javascript is EvoPdf. I have downloaded the zip file of 52mb done the install – which by the way could not be easier: add reference to dll, copy another, and then call the following method:

usingEvoPdf.HtmlToPdf;
private void ConvertURLToPDF()

    {

        string urlToConvert = Request["url"];
        PdfConverter pdfConverter = new PdfConverter();

        pdfConverter.LicenseKey = "xxxxxxx";

        pdfConverter.PdfDocumentOptions.PdfPageSize = PdfPageSize.A4;

        pdfConverter.PdfDocumentOptions.PdfCompressionLevel = PdfCompressionLevel.Normal;

        pdfConverter.PdfDocumentOptions.PdfPageOrientation = PdfPageOrientation.Portrait;

        pdfConverter.PdfDocumentOptions.LiveUrlsEnabled = true;

        pdfConverter.JavaScriptEnabled = true; //the important bit – waits for javascript

        pdfConverter.ConversionDelay = 10;

        pdfConverter.InterruptSlowJavaScript = false;

        pdfConverter.PdfDocumentOptions.JpegCompressionEnabled = true;

        pdfConverter.PdfDocumentOptions.FitWidth = true;
        byte[] pdfBytes = pdfConverter.GetPdfBytesFromUrl(urlToConvert);

        System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;

        response.Clear();

        response.AddHeader("Content-Type", "application/pdf");

        response.AddHeader("Content-Disposition", String.Format("attachment; filename=Output.pdf; size={0}", pdfBytes.Length.ToString()));

        response.BinaryWrite(pdfBytes);

        response.End();

}

The license is a little hefty, but you can trail the full version to see if it suits your needs before dusting off the credit card – the only thing is the outputed PDF will have a watermark over it until you get a license.

Ajax using .Net and jQuery – Revised and improved with help from Json

Dave — Thu, 03 Dec 2009 14:26:25 +0000

I previously wrote a post outlining a simpler method of making asynchronous calls with jQuery. It turns out that in practice that method was exactly that – too simple. It works fine when you only need one value back, but if you need to work with something a little more complex then try out my new method that uses a JSON object. So the basic overview is as follows:

create an object server-side on page load and add it to the DOM
populate the object using javascript
pass it back to a webservice using jquery’s ajax method and json
use the new object serverside and pass it back

Ok, so lets get started by creating the object in your webservice:

public class Person

    {

        public string Name { get; set; }

        public string ContactNumber { get; set; }

        public string Description { get; set; }

    }

Then in your page load you can inject this object into the DOM:

var objPerson = new Webservice.Person();

var js = new JavaScriptSerializer();

Page.ClientScript.RegisterArrayDeclaration("_person", js.Serialize(objPerson));

Now you can use this object with javascript:

…
function AjaxMethodJSON(serviceFn, paramArray, successFn, errorFn) {

    $.ajax({

        type: "POST",

        url: serviceFn,

        contentType: "application/json; charset=utf-8",

        data: "{‘clientobject’:" + JSON.stringify(paramArray) + "}",

        dataType: "json",

        success: successFn,

        error: errorFn

    })

;
…

$("#btnSubmit").click(function() {

        objPerson.Name = $(‘#txtName’).val();

        objPerson.ContactNumber = $(‘#txtContactNumber’).val();

        objPerson.Description = $(‘#txtDescription’).val();

        AjaxMethodJSON("/webservices/Webservice.asmx/UpdatePerson", objPerson, AjaxSuccessStep, AjaxFailed);

    });

If you have been paying attention you may be thinking – stringify? The official explanation from json.org: If the stringify method sees an object that contains a toJSON method, it calls that method, and stringifies the value returned. This allows an object to determine its own JSON representation. So remember to add a reference to json2.js upstream from this code.

function AjaxSuccessStep(result) {

        if (result != null) {

            var obj = result.d;

            objPerson = JSON.parse(obj);

//got the updated object back, now you can            

//do some more stuff with it

        }

    }

There you go. This works very well when you are stepping through a wizard and updating a few fields with each step.

Tech-Ed Day 2

Dave — Tue, 04 Aug 2009 08:47:45 +0000

What a full day – to be honest its all a blur. But fear not I tweeted up a storm and will revisit this post and update once the dust has settled. Suffice to say there were some awesome talks (and some not so awesome ).

I seized a gap in lectures in the afternoon and took my sedatory body for a run along the beachfront and a dip in the ocean. What a pleasure to just go for a swim and not fear loosing extraneous body bits to frostbite – and this is in the middle of ‘winter’. Turns out I needed the mental refresh as I headed back to attend a session by Gail Shaw on Query hints – I know nothing about sql in comparison to her. mercy.

I got taken out for dinner by the gang at IS Partners to a great little italian place on Florida Road, which seems to be Durban’s version of Kloof street. Shot guys, I had a really good evening – if Cape Town ever ends up under water due to global warming – I will come and see if I can be of any value.

Tech-Ed 2009

Dave — Mon, 03 Aug 2009 09:58:19 +0000

So here I am, Durban by the sea, for the 09 instalment of Microsoft’s Tech-Ed. I have not been in Durbs for many years, but there’s something about the place that agrees with me, stepping of the plane you are welcomed by a thick blanket of humidy – and it’s the middle of winter. I bought a great book to keep me company on the long flight (which included a stop in the friendly city), its inspirational to read stories where people have taken hold of dreams and not let situations deter then from success.

I met Ugene from lightstone (?) on the flight who was also on the way to the event. He was a dead give away – after taking an hour to totally absorb every word he computer mag the whipped out his laptop and plugged himself into a movie. I introduced myself and guessed his reason for traveling to Durban and was right. Turns out that he has been to the last seven tech-eds. Grief, he deserves an award of some sort – matching microsoft mousepads or something. He was totally amped and said the parties are not to be missed.. I smiled and nodded, but remained a little sceptical.

The opening keynote had all the expected elements: big audio visuals, microsoft evangelism, a couple google bashing jokes and demos that mostly worked. There were some very cool things, the ones that come to mind are:
Visual Studio 2010
Control click to auto generate new methods and properties
Windows 7
making use of gestures
Project Gemini (Donald Farmer)
100 million rows in excel, sorted and filtered instantaniously.
Expression Blend Sketching storyboards

I had dinner with my brother, Gavin, and was introduced to Gail Shaw – one of two Microsoft sql mvp’s in the country. It is so amusing to see uber geeks getting there annual chance to be rock stars amongst the few people that actually get what they do. After spending some time with the guys from IS partners, I called it a night made my way back to the city lodge in the warm drizzle.

Tomorrow it begins in ernest with sessions every hour from eight till five. Hoping to get a gap to go for a dip in the warm ocean…

Ajax using .Net and jQuery

Dave — Tue, 28 Jul 2009 11:50:10 +0000

I am not a fan of the classic method of implementing ajax in .net – scriptmanagers and updatepanels. The load on the front end is pretty big (100kb+), especially considering local bandwidth restrictions and challenges. So I set out to find a better way as one does when one feels that something is not quite right.

So it turns out that jQuery comes to the rescue – again.

<div id="clickme1">whats the time? (using code behind)</div>
<div id="clickme2">whats the time? (using a webservice)</div>
<div id="result" style="border:1px solid red;padding:5px;">nothing yet</div>
<script src="/js/v4/jquery.132.min.js" type="text/javascript"></script><script type="text/javascript">// [CDATA[
function AjaxSucceeded(result) {$(‘#result’).html("good " + result.d);}
function AjaxFailed(result) {$(‘#result’).html("bad " + result.d);}
function AjaxMethod(serviceFn, paramArray, successFn, errorFn) {

    var paramList = ”;

    if (paramArray.length > 0) {

        for (var i = 0; i < paramArray.length; i += 2) {             if (paramList.length > 0) paramList += ‘,’;

            paramList += ‘"’ + paramArray[i] + ‘":"’ + paramArray[i + 1] + ‘"’;

        }

    }

    paramList = ‘{‘ + paramList + ‘}’;
    $.ajax({

        type: "POST",

        url: serviceFn,

        contentType: "application/json; charset=utf-8",

        data: paramList,

        dataType: "json",

        success: successFn,

        error: errorFn

    })

;}
$(document).ready(function() {

            $(‘#clickme2′).click(function() { AjaxMethod("/webservices/webservice.asmx/GetDate", [], AjaxSucceeded, AjaxFailed); });

            $(‘#clickme1′).click(function() { AjaxMethod(window.location.pathname + "/GetDate", [], AjaxSucceeded, AjaxFailed); });

        });

// ]]></script>

Using a webservice (clickme2 event):

[ScriptService]

[WebService(Namespace = "http://tempuri.org/")]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

public class WebService : System.Web.Services.WebService

{

[WebMethod()]

public string GetDate()

{

return DateTime.Now.ToLocalTime().ToString();

}

}

And the code behind (clickme1 event)::

[WebMethod()]

public static string GetDate()

{

return DateTime.Now.ToLocalTime().ToString();

}

And there you go – ajax functionality without the bloat. This code has yet to make it into the harsh light of a production environment, but I have successfully used it to return not just one value, but xml data too (see example below), which opens up huge possibilities for front end goodness. The method below makes use of caching which increases performance hugely, but that’s a topic for another day.

function ShowMyPosts(result){
var output ="";
$(result.d).find(‘item’).each(function() {

var title= $(this).attr(‘title’);

var link= $(this).find(‘link’).text();

output += "

" + title + " : " + title+ " : " + link + "


";
});
$(‘#result’).html(output);

}
$(document).ready(function() {

$(‘#clickme3′).click(function() { AjaxMethod(window.location.pathname + "/GetXML", ["url", "http://davidrussellr.wordpress.com/feed/", "cachename", "test2"], ShowMyPosts, AjaxFailed); });
});

And the code behind:

[WebMethod()]

public static string GetXML(string url, string cachename)

{

XmlDocument xmlDoc = FetchXML.ReturnXmlDoc(url, cachename);

return xmlDoc.InnerXml;

}

.Net, HTML mails and embedded images

Dave — Tue, 28 Jul 2009 10:50:27 +0000

So recently I needed to take an image uploaded by the client and embed it into an email as part of a ‘send to a friend’ type piece of functionality. After much trial and error I managed to put all the pieces together – the tricky bit is taking an image that only lives in memory, attaching it to an email and then referencing that image from the html.

So here goes: (ImageData in the example method is the base64 encoded image data that was uploaded)

publicstaticbool SendHTMLMailWithEmbeddedImage(string ContactEmail, string FriendEmail, string ImageData)
{
try

{
byte[] imageBytes = Base64DecodeString(ImageData);

MemoryStream memorystream = new MemoryStream(imageBytes);

memorystream.Seek(0, SeekOrigin.Begin);

System.Drawing.Image img = ByteArrayToImage(imageBytes);
MailMessage emailEnquiry = new MailMessage(ContactEmail, FriendEmail);
emailEnquiry.Subject = "here’s a gripping email";

emailEnquiry.IsBodyHtml = true;

Attachment objAttachment = new Attachment(memorystream, "AnAttachedImage.jpg");

emailEnquiry.Attachments.Add(objAttachment);

String ContentID = "TheAttachedImage";

objAttachment.ContentId = ContentID;
StringBuilder sb = new StringBuilder();
sb.Append("…lots of html here..<img src=’cid:" + ContentID + "’>…ending off with lots of html here too…");
emailEnquiry.Body = sb.ToString();
SmtpClient sendEnquiry = new SmtpClient();

sendEnquiry.Host = WebConfigUtil.GetAppSetting("MySmtpServerName");

sendEnquiry.Send(emailEnquiry);
return true;
}
catch (Exception er)

{

if (!HttpContext.Current.IsDebuggingEnabled)

{

return false;

}

else

throw er;

}
}

So there you go. I have simplified the method in this example by taking out logging etc, so hopefully it still works / makes sense. The part that took the longest to fathom was making the link between the attached image and the rendered html using the “cid:”.