Nov 202013
 

Hello everyone!

A new version of our JavaScript library is now available. This release addresses compatibility issues with IE11. If your web application is compatible with IE11, we strongly recommend that you upgrade to the new version.

The new DYMO Label Framework JavaScript Library 1.2.5 is available here:  http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.1.2.5.js

The latest has been updated to version 1.2.5 as well: http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.latest.js

Dec 162011
 

The previous post demonstrated different ways of printing QR-code from a .NET application. This blog post will demonstrate how to achieve the same goal from a web application. The complete sample is available here. The corresponding JavaScript is here.

Prerequisites

First, make sure the latest DYMO Label software is installed. It is always available on DYMO web-site, at the time of writing it is version 8.3.1.

Use Barcode Object

The easiest way to print QR-code is to use built-in support for QR-code in DYMO Label Framework. First, design your label using DYMO Label software. Unfortunately, DYMO Label itself does not have ability to specify QR-code barcode type in the UI yet. So, add the Barcode object to the label and put it into desired position. Don’t specify the barcode symbology, use the default Code39. Save the label in to a file, open the file in any XML editor and change thetag to “QRCode”.

<BarcodeObject>
    <Name>Barcode</Name>
    <ForeColor Alpha="255" Red="0" Green="0" Blue="0" />
    <BackColor Alpha="0" Red="255" Green="255" Blue="255" />
    <LinkedObjectName></LinkedObjectName>
    <Rotation>Rotation0</Rotation>
    <IsMirrored>False</IsMirrored>
    <IsVariable>False</IsVariable>
    <Text></Text>
   <Type>QRCode</Type>
    <Size>Large</Size>
    <TextPosition>None</TextPosition>
    <TextFont Family="Arial" Size="8" Bold="False" Italic="False" Underline="False" Strikeout="False" />
    <CheckSumFont Family="Arial" Size="8" Bold="False" Italic="False" Underline="False" Strikeout="False" />
    <TextEmbedding>None</TextEmbedding>
    <ECLevel>0</ECLevel>
    <HorizontalAlignment>Left</HorizontalAlignment>
    <QuietZonesPadding Left="0" Top="0" Right="0" Bottom="0" />
</BarcodeObject>

See Barcode.label from the sample. After the label is ready, the actual steps to print it is quite easy: open the label, set desired data, print. Here is a snippet from the sample:

printButton.onclick = function()
{
    try
    {
        if (!barcodeLabel)
            throw "Load label before printing";

        if (!printersSelect.value)
            throw "Select printer.";

        barcodeLabel.setObjectText('Barcode', 'http://developers.dymo.com');
        barcodeLabel.print(printersSelect.value);
    }
    catch(e)
    {
        alert(e.message || e);
    }
}

First, we check that the label is loaded and the printer is selected. Next, the barcode data is set to be the blog’s URL. And finally, the label is printed.

Use Image Object

Printing QR-code by using Barcode object is easy. The only drawback, it is hard to control the actual barcode size. tag can be used for that but it support only three predefined sizes Small/Medium/Large, but still the overall size will depend on the actual barcode data. The longer the data string, the larger is the barcode. So, the idea is to use some library to generate QR-code image of desired size, and then print it using the Image object. As before, design a label using DYMO Label software. Put an Image object on the label where the barcode should be printed. Set the Image objet size to the desired barcode size. When specifying the barcode image size in pixels calculate it based on the printer resolution, that is 300 dpi for LabelWriter printers and 180 dpi for Tape printers. For example, if you want the barcode to be 1” in size, specify the barcode image size as 300×300 pixels. See BarcodeAsImage.label from the sample project.

Image object accepts image data as a string that contains base64-encoded png stream. The question is, how to get/generate this string. Again, there are several ways of doing that.

Generate and base64-encode QR-code image on the server-side

One way is to generate QR-code image on the server using some library. Then encode the image using base64 and return it to the client as a string. Finally, on the client side, call setObjectText on the Image object and print.

printAsImageButton.onclick = function()
{
    try
    {
        if (!barcodeAsImageLabel)
            throw "Load label before printing";

        if (!printersSelect.value)
            throw "Select printer";

        $.get("qr.base64", function(qr)
        {
            try
            {
                barcodeAsImageLabel.setObjectText('Image', qr);

                barcodeAsImageLabel.print(printersSelect.value);
            }
            catch(e)
            {
                alert(e.message || e);
            }
        }, "text");

    }
    catch(e)
    {
        alert(e.message || e);
    }
}

In the sample, we just request “qr.base64” resource that contains precalculated QR-code image for “http://developers.dymo.com”. In real application, you will probably pass the data to be encoded as a resource parameter.

Generate QR-code image on the server-side and base64-encode it on the client-side.

Base64-encoded strings are larger then binary png data. So, to reduce network traffic, we can return original png data from the server and base64-encode it on the client. To encode the data we will create , render our image on it, and then get encoded data using canvas.toDataURL() method.

printAsImageCanvasButton.onclick = function()
{
    try
    {
        if (!barcodeAsImageLabel)
            throw "Load label before printing";

        if (!printersSelect.value)
            throw "Select printer.";

        var img = new Image();
        img.onload = function()
        {
            try
            {
                var canvas = document.createElement('canvas');
                canvas.width = img.width;
                canvas.height = img.height;

                var context = canvas.getContext('2d');
                context.drawImage(img, 0, 0);

                var dataUrl = canvas.toDataURL('image/png');
                var pngBase64 = dataUrl.substr('data:image/png;base64,'.length);

                barcodeAsImageLabel.setObjectText('Image', pngBase64);
                barcodeAsImageLabel.print(printersSelect.value);
            }
            catch(e)
            {
                alert(e.message || e);
            }
        };
        img.onerror = function()
        {
            alert('Unable to load "qr.png"');
        };
        img.src = 'qr.png';
    }
    catch(e)
    {
        alert(e.message || e);
    }
}

Note: image loading is asynchronous process. So, we can’t just assign img.src property and immediately draw it on a canvas; we have to wait until the image is loaded completely from the server. To handle that, we do main work in onload handler. also, toDataURL returns data url, to get the data itself, we have to remove the url prefix.

Again, as in the previous case, qr.png resource contains recalculated QR-code image for “http://developers.dymo.com”. In real application, you will probably pass the data to be encoded as a resource parameter.

A drawback of this method is that it requires support in the browser. All major browsers already support it, but be aware that in Internet Explorer it is supported starting from version 9 only.

Use third-party service

Instead of generating QR-code image on your own server, is it possible to use one of the many free online QR-code generator/service? The answer is yes, but it is even more trickier than the previous way. The problem, as usual in web development, is the security. But default is it not possible to grab canvas pixels if an image from a different domain has been drawn on the canvas. It is possible to overcome it, but it requires three parties to participate properly. First, your JavaScript has to set img.crossOrigin property to ‘anonymous’. This will tell the browser that you are trying to access a cross-domain resource, so the browser can send appropriate request headers, e.g. the browser will not send cookies. Next, the server itself should allow its resources to be accessible from other domains. Only few of many QR-code online generators do allow it. And the last, the browser itself should support CORS for . It is very recent addition to the standards, so at the time of writing only Chrome does support it. In any other browsers you will still get “security exception” error. Here are some links regarding and cross-domain limitations:

http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#security-with-canvas-elements

http://blog.chromium.org/2011/07/using-cross-domain-images-in-webgl-and.html

http://code.google.com/p/chromium/issues/detail?id=82042

Update (2011-12-20): works in Firefox 9 as well.

printAsImageCanvas2Button.onclick = function()
{
    try
    {
        if (!barcodeAsImageLabel)
            throw "Load label before printing";

        if (!printersSelect.value)
            throw "Select printer.";

        var img = new Image();
        img.crossOrigin = 'anonymous';
        img.onload = function()
        {
            try
            {
                var canvas = document.createElement('canvas');
                canvas.width = img.width;
                canvas.height = img.height;

                var context = canvas.getContext('2d');
                context.drawImage(img, 0, 0);

                var dataUrl = canvas.toDataURL('image/png');
                var pngBase64 = dataUrl.substr('data:image/png;base64,'.length);

                barcodeAsImageLabel.setObjectText('Image', pngBase64);
                barcodeAsImageLabel.print(printersSelect.value);
            }
            catch(e)
            {
                alert(e.message || e);
            }
        };
        img.onerror = function()
        {
            alert('Unable to load qr-code image');
        };
        img.src = 'https://chart.googleapis.com/chart?chs=300x300&cht=qr&chl=http%3A//developers.dymo.com&choe=UTF-8';
    }
    catch(e)
    {
        alert(e.message || e);
    }
}

The code is very similar to the previous example. The only difference is that we set img.crossOrigin property and we use Google’s Infographics API to generate the qr-code image. Notice that in this example the image is generated dynamically, and barcode data is passed as the part of the url.

Pure client-side JavaScript

At the time of writing, it seems there is no self-contained pure JavaScript solutions to create QR-code images using <canvas> completely on the client-side. In the future it might be one more way of doing QR-code printing.

Conclusion

It is quite simple to print QR-code barcode even if built-in support is somewhat limited.

Nov 292011
 

This blog post will demonstrate how it is easy to print a label with a QR-code barcode from any .NET application. Even more, it will show how to do that in two different ways. The sample VS 2008 project is available here.

Prerequisites

First, make sure the latest DYMO Label software is installed. It is always available on DYMO web-site, at the time of writing it is version 8.3.1. Next, in Visual Studio create a new .NET project and add a reference to DYMO.Label.Framework assembly. This will make possible to use DYMO Label Framework API in the project.

Use Barcode Object

The easiest way to print QR-code is to use built-in support for QR-code in DYMO Label Framework. First, design your label using DYMO Label software. Unfortunately, DYMO Label itself does not have ability to specify QR-code barcode type in the UI yet. So, add the Barcode object to the label and put it into desired position. Don’t specify the barcode symbology, use the default Code39. Save the label in to a file, open the file in any XML editor and change the <Type> tag to “QRCode”.

<BarcodeObject>
    <Name>Barcode</Name>
    <ForeColor Alpha="255" Red="0" Green="0" Blue="0" />
    <BackColor Alpha="0" Red="255" Green="255" Blue="255" />
    <LinkedObjectName></LinkedObjectName>
    <Rotation>Rotation0</Rotation>
    <IsMirrored>False</IsMirrored>
    <IsVariable>False</IsVariable>
    <Text></Text>
    <Type>QRCode</Type>
    <Size>Large</Size>
    <TextPosition>None</TextPosition>
    <TextFont Family="Arial" Size="8" Bold="False" Italic="False" Underline="False" Strikeout="False" />
    <CheckSumFont Family="Arial" Size="8" Bold="False" Italic="False" Underline="False" Strikeout="False" />
    <TextEmbedding>None</TextEmbedding>
    <ECLevel>0</ECLevel>
    <HorizontalAlignment>Left</HorizontalAlignment>
    <QuietZonesPadding Left="0" Top="0" Right="0" Bottom="0" />
</BarcodeObject>

See Barcode.label file in the sample project. After the label is ready, the actual steps to print it is quite easy: open the label, set desired data, print. Here is a snippet from the sample:

private void PrintBarcodeButton_Click(object sender, RoutedEventArgs e)
{
    // load label template
    var label = DYMO.Label.Framework.Label.Open(
        Application.GetResourceStream(
            new Uri("Barcode.label", UriKind.Relative)).Stream);

    // set barcode data
    label.SetObjectText("Barcode", "http://developers.dymo.com");

    // print
    label.Print(PrintersComboBox.Text);
}

First, label is loaded from a file, stored as a resource in the application assembly. Next, the barcode data is set to be the blog’s URL. And finally, the label is printed on the printer selected in the UI.

Use Image Object

Printing QR-code by using Barcode object is easy. The only drawback, it is hard to control the actual barcode size. <Size> tag can be used for that but it support only three predefined sizes Small/Medium/Large, but still the overall size will depend on the actual barcode data. The longer the data string, the larger is the barcode. So, the idea is to use some library to generate QR-code image of desired size, and then print it using the Image object. As before, design a label using DYMO Label software. Put an Image object on the label where the barcode should be printed. Set the Image’s Scale Mode to None to avoid image scaling and possible problems with the scanning/reading of the printed barcode. See BarcodeAsImage.label from the sample project. Then use selected library to generate the QR-code image. When specifying the barcode image size in pixels calculate it based on the printer resolution, that is 300 dpi for LabelWriter printers and 180 dpi for Tape printers. For example, if you want the barcode to be 1” in size, specify the barcode image size as 300×300 pixels. Actuals API calls are very similar to the first case.

private void PrintBarcodeAsImageButton_Click(object sender, RoutedEventArgs e)
{
    // load label template
    var label = DYMO.Label.Framework.Label.Open(
        Application.GetResourceStream(
            new Uri("BarcodeAsImage.label", UriKind.Relative)).Stream);

    // set data as a barcode image
    var imageStream = Application.GetResourceStream(
            new Uri("qr.png", UriKind.Relative)).Stream;

    label.SetImagePngData("Image", imageStream);

    // print
    label.Print(PrintersComboBox.Text);
}

First, label is loaded from a file, stored as a resource in the application assembly. Next, the barcode image is “generated”; for the simplicity, already created png file is used instead of library calls. Next, the image data is assigned to the Image object. And finally, the label is printed on the printer selected in the UI.

Conclusion

It is quite simple to print QR-code barcode even if built-in support is somewhat limited. The next post will show how to do the same thing by using DYMO Label JavaScript library.

Nov 172011
 

Here is one more sample demonstrates capabilities of DYMO Label JavaScript library. The correspondent JavaScript file is here.

Getting Printers

First, the sample shows how to retrieve a list of available DYMO printers. For each printer it shows all the available properties. To get the printer list use dymo.label.framework.getPrinters function. The function returns an array contains information regarding each printer. The sample calls getPrinters and then put all the information onto a table, see createPrintersTable() for details.

Note: There are helpful function to filter the result list to contain only LabelWriter or Tape printers; use dymo.label.framework.getLabelWriterPrinters or dymo.label.framework.getTapePrinters accordingly. This might be useful if your application is designed to print on die-cut labels or D1 tapes only.

Print Multiple Labels

Next, the sample shows how to print multiple labels at once, in one print job. The sample leverages the library’s LabelSet functionality do archive that. For each printer the sample creates one label set record represent data to be printed on one label. also the sample demonstrates how to apply different text styles to the print data. It uses a feature called text markup, the ability to apply formatting attributes/tags very similar to HTML ones. 

// create label set to print printers' data
var labelSetBuilder = new dymo.label.framework.LabelSetBuilder();
for (var i = 0; i < printers.length; i++)
{
    var printer = printers[i];

    // process each printer info as a separate label
    var record = labelSetBuilder.addRecord();

    // compose text data
    // use framework's text markup feature to set text formatting
    // because text markup is xml you can use any xml tools to compose it
    // here we will use simple text manipulations to avoid cross-browser compatibility.
    var info = "<font family='Courier New' size='14'>"; // default font
    info = info + "Printer: <b>" + printer.name + "n</b>"; 
    info = info + "PrinterType: " + printer.printerType;
    info = info + "n<font size='10'>is local: " + printer.isLocal;
    info = info + "nis online: " + printer.isConnected + "</font>";

    if (typeof printer.isTwinTurbo != "undefined")
    {
        if (printer.isTwinTurbo)
            info = info + "<i><u><br/>The printer is TwinTurbo!!!</u></i>";
        else
            info = info + "<font size='6'><br/>Oops, the printer is NOT TwinTurbo</font>";
    }

    if (typeof printer.isAutoCutSupported != "undefined")
    {
        if (printer.isAutoCutSupported)
            info = info + "<i><u><br/>The printer supports auto-cut!!!</u></i>";
        else
            info = info + "<font size='6'><br/>The printer does not supports auto-cut</font>";
    }

    info = info + "</font>";

    // when printing put info into object with name "Text"
    record.setTextMarkup("Text", info);
}

See print() function for a complete sample.

Note: Here is another blog post regarding using text markup. And one more regarding printing multiple labels.

Oct 072011
 

A new version of DYMO Label Framework JavaScript library is available.

This version adds support for Opera 11.51 on Mac and Windows.

The js script file is available from http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.1.2.4.js.

The http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.latest.js has been updated to version 1.2.4 as well.

Oct 042011
 

There are two ways of providing dynamic text data to be printed on your labels. In both cases the text can be “styled”, so different parts of the text will use different fonts, sizes and/or styles.

The first way covers most use cases for text formatting needs, it is simple, and, of cause, has some limitations. The limitation is that it supports line-by-line formatting only. So, each line can have its own formatting, but all characters in the same line will use the same formatting. If this is OK for your application, then here are the steps needed to utilize this method. first, you have to design you label layout/template. The easiest way to design a label is by using DYMO Label software. While designing, type a sample data for a label object, and apply some formatting, on line by line basis, e.g. make the first line bold, save the file, and put it on your server. 

image

Those are manual steps, now we will need some JavaScript. Load the label by using openLabelXml. Now you can set your real data by using setLabelText or, if you need to print multiple labels, by using a LabelSet. You pass a plain string without any formatting to the setLabelText method, and the library will apply line-by-line formatting for you based on the sample data in the label file. For example, if you call setLabelText(‘Will E. CoyotenACME Birdingn2200 Desert Meadows WaynLas Vegas, NV 89122’), the output will be like that:

image

The second way to format the text is by using so called “Text Markup” feature. It is some what more complex than the first formatting method, but in return you have the full control over the font attributes and can do character-by-character formatting. First, you design your label as described above, but you don’t have to specify any sample data. Next you have to construct a “text markup”.  A text markup is an xml string contains tags controlling font attributes, plus plain text data. The Supported tags are ones similar to HTML tags: <font>, <b>, <i>, <u>, <s>, <br>. Full xml-schema definition is available here. After you have the markup text, you can print it by using a LabelSet and setTextMarkup method.

var labelSet = new dymo.label.framework.LabelSetBuilder();
var record = labelSet.addRecord();

var textMarkup = '...';
record.setTextMarkup('Text', textMarkup);
label.print('DYMO LabelWriter 450', null, labelSet.toString());

Here is an example demonstrates different formatting capabilities: http://labelwriter.com/software/dls/sdk/samples/js/TextMarkup/TextMarkup.html, and the corresponded JavaScript http://labelwriter.com/software/dls/sdk/samples/js/TextMarkup/TextMarkup.js. Type anything into the “Text to Print” text box and click on any button below. The output should correspond to the button’s caption. The corresponded text markup will be copied to the “Text Markup” text box, so you can examine it without going into JavaScript debugger. Also, you can just type any text markup in the box and print it by clicking on “Print text markup” button. Just make sure it is a correct xml and correct markup. If it is not, a runtime error/exception is thrown.

Sep 162011
 

A new version of DYMO Label Framework JavaScript library is available.

This version improves detection of supported browsers, or more precise unsupported ones. There is a known problem with Safari 5.1 running in 32-bit mode on both Mac OS X 10.6 and 10.7. Before version 1.2.3 the library did not detect this problem. Now, the call to dymo.label.framework.checkEnvironment() will return an error.

The js script file is available from http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.1.2.3.js.

The http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.latest.js has been updated to version 1.2.3 as well.

Sep 072011
 

A new version of DYMO Label Framework JavaScript library is available.

Thanks to our friends at lambslist.com a subtle bug in Mac version of DYMO Label software has been discovered (and fixed). The problem manifests itself at print time, when the label data is printed using the default font instead of one specified in the label file. The fix for DYMO Label software is scheduled for the next release, 8.4. In the meantime the js script library has been updated to include a workaround for the problem.

The js script file is available from http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.1.2.2.js.

The http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.latest.js has been updated to version 1.2.2 as well.

Jul 272011
 

A new version of DYMO Label Framework JavaScript library is available. This version adds support for Mac OS X 10.7 (Lion).

The js script file is available from http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.1.2.0.js.

The http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.latest.js has been updated to version 1.2.0 as well.

All major browsers are supported: Safari 4-5.1, Firefox 3-5, Chrome, Opera 10. Opera 11 is not supported at the time of writing.

Jul 202011
 

Update: A subtle bug has been found in the version 1.1.0. It is fixed now and new version 1.1.1 is available.

A new version of DYMO Label Framework JavaScript library is available. This version fixes a problem with setting a label data from Internet Explorer 9. The js script file is available from http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.1.1.1.js

The http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.latest.js has been updated to version 1.1.1 as well.