341 lines
24 KiB
HTML
341 lines
24 KiB
HTML
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Method reference</title><link rel="stylesheet" type="text/css" href="manual.css"><meta name="generator" content="DocBook XSL Stylesheets V1.76.0"><link rel="home" href="index.html" title="JpGraph Manual"><link rel="up" href="ch25.html" title="Chapter 25. PDF417 (2D-Barcode)"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Method reference</th></tr><tr><td width="20%" align="left"> </td><th width="60%" align="center">Chapter 25. PDF417 (2D-Barcode)</th><td width="20%" align="right"> </td></tr></table><hr></div><div class="sect1" title="Method reference"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2602315"></a>Method reference</h2></div></div></div>
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<div class="sect2" title="Encoder methods"><div class="titlepage"><div><div><h3 class="title"><a name="id2602322"></a>Encoder methods</h3></div></div></div>
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<p>All encoder methods are accessed on an instance of <code class="code">class
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PDF417Barcode</code>
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</p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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2
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3
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">...
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$encoder = new PDF417Barcode($columns,$errlevel);
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...</span></pre></td></tr></table></div><p>
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</p>
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<div class="sect3" title="PDF417Barcode"><div class="titlepage"><div><div><h4 class="title"><a name="id2602345"></a>PDF417Barcode</h4></div></div></div>
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<p><code class="code">PDF417Barcode($aNumCols=10, $aErrLevel=2)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>To create a new PDF417 encoder with a chosen number of columns and error
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level. Please note that these parameters can also be adjusted using the methods
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described below. The method will throw exceptions if the parmeters are outside
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there valid range.</p>
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<p><code class="code">$aNumCols</code> , an integer in the range [2,30]</p>
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<p><code class="code">$aErrLevel</code>, an integer in the range [0,8]</p>
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<p><span class="bold"><strong>Returns:</strong></span></p>
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<p>A new encoder which is used by the backend to generate the barcode
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label.</p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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2
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">// Create a new encoder with 20 columns
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$encoder = new PDF417Barcode(20);</span></pre></td></tr></table></div><p>
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</p>
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</div>
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<div class="sect3" title="SetColumns"><div class="titlepage"><div><div><h4 class="title"><a name="id2602389"></a>SetColumns</h4></div></div></div>
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<p><code class="code">SetColumns($aCols)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Specify number of data columns. This should be a value in the range [2-30]
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(inclusively) . Note that it is also possible to specify the number of columns
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in the instantiation of the encoder.</p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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2
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3
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">// Create a new encoder with 20 columns
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$encoder = new PDF417Barcode();
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$encoder->SetColumns(20);</span></pre></td></tr></table></div><p>
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</p>
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<p><span class="bold"><strong>Note:</strong></span></p>
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<p>The number of rows will be automatically adjusted to fit the data and the
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error correction codewords as specified by the error level setting. The number
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of rows is not directly user configurable.</p>
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</div>
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<div class="sect3" title="SetErrLevel"><div class="titlepage"><div><div><h4 class="title"><a name="id2602416"></a>SetErrLevel</h4></div></div></div>
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<p><code class="code">SetErrLevel($aErrLevel)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Specify the chosen level of error correction. </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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2
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$encoder = new PDF417Barcode();
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$encoder->SetErrLevel(5);</span></pre></td></tr></table></div><p>
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</p>
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<p><span class="bold"><strong>Note:</strong></span></p>
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<p>A high error level will limit the number of payload data since the total
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number of data in the label is fixed.</p>
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</div>
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<div class="sect3" title="SetTruncated"><div class="titlepage"><div><div><h4 class="title"><a name="id2602519"></a>SetTruncated</h4></div></div></div>
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<p><code class="code">SetTruncated($aTrunc=true)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Specify that barcode should use the truncated PDF format. This will make the
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barcode slightly narrower and might be used where the physical space is at
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premium. </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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2
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$encoder = new PDF417Barcode();
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$encoder->SetTruncated ();</span></pre></td></tr></table></div><p>
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</p>
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<p><span class="bold"><strong>Note:</strong></span></p>
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<p>Not all barcode scanners can handle truncated PDF417.</p>
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</div>
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</div>
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<div class="sect2" title="Common backend methods"><div class="titlepage"><div><div><h3 class="title"><a name="id2602572"></a>Common backend methods</h3></div></div></div>
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<p>The backend is responsible for the actual output of the barcode (see <a class="xref" href="ch25s03.html#fig.pdf417-encodation-overview" title="Figure 25.4. Overview of the interaction between encoder and backends">Figure 25.4. Overview of the interaction between encoder and backends</a>). </p>
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<p>It is possible to either create an image or a postscript backend. In the creation
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of the backend an instance of the encoder is given as the second argument. The
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actual output from the script (to create the barcode label) is done with a call to
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the <code class="code">Backend::Stroke()</code> method. As usual this call should be the last
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line in the script if it is used to send the image back to the browser. </p>
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<p>The method call to Stroke() should always be guarded with a <code class="code">try{} catch
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{}</code> statement.</p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">try {
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$encoder = new PDF417Barcode( $columns, $errlevel);
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$backend = PDF417BackendFactory::Create( BACKEND_IMAGE, $encoder);
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// .. Output formatting
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$backend->Stroke();
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}
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catch(JpGraphException $e) {
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echo 'PDF417 Error: '.$e->GetMessage();
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}</span></pre></td></tr></table></div><p>
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</p>
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<p>In the example above we have chosen to create an image encoder (specified by
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constant <code class="code">BACKEND_IMAGE</code>) by default the image format used will be PNG
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which is also the recommended format.</p>
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<div class="sect3" title="Stroke"><div class="titlepage"><div><div><h4 class="title"><a name="id2602634"></a>Stroke</h4></div></div></div>
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<p><code class="code">Stroke($aData, $aFile='')</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Encode a specific data string entered as the first argument and send the
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barcode output, depending on backend, either directly back to the browser as an
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image or return the Postscript representation as a string. </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-inlinetags"><?php</span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> Data to be encoded</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$data</span><span class="hl-code"> = ... ;
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</span><span class="hl-reserved">try</span><span class="hl-code"> </span><span class="hl-brackets">{</span><span class="hl-code">
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...
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</span><span class="hl-var">$backend</span><span class="hl-code">-></span><span class="hl-identifier">Stroke</span><span class="hl-brackets">(</span><span class="hl-var">$data</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-brackets">}</span><span class="hl-code"> </span><span class="hl-reserved">catch</span><span class="hl-brackets">(</span><span class="hl-code"> </span><span class="hl-identifier">JpGraphException</span><span class="hl-code"> </span><span class="hl-var">$e</span><span class="hl-brackets">)</span><span class="hl-code"> </span><span class="hl-brackets">{</span><span class="hl-code">
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...
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</span><span class="hl-brackets">}</span><span class="hl-code">
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</span><span class="hl-inlinetags">?></span></pre></td></tr></table></div><p>
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</p>
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</div>
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<div class="sect3" title="SetVertical"><div class="titlepage"><div><div><h4 class="title"><a name="id2602647"></a>SetVertical</h4></div></div></div>
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<p><code class="code">SetVertical($aFlg=true)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Draw the barcode vertically instead of the default horizontal direction</p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$backend->SetVertical();</span></pre></td></tr></table></div><p>
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</p>
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</div>
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<div class="sect3" title="SetScale"><div class="titlepage"><div><div><h4 class="title"><a name="id2602715"></a>SetScale</h4></div></div></div>
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<p><code class="code">SetScale($aScale)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Will arbitrary scale the generated barcode image. Scale factor is specified as
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a floating point number . </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$backend->SetScale(2.5);</span></pre></td></tr></table></div><p>
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</p>
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</div>
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<div class="sect3" title="SetModuleWidth"><div class="titlepage"><div><div><h4 class="title"><a name="id2602754"></a>SetModuleWidth</h4></div></div></div>
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<p><code class="code">SetModuleWidth($aWidth)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Specifies the module width to be used in the barcode. The module width is
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interpretated differently depending on whether it is applied on an image or a
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postscript backend. The module width will determine the physical width of the
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overall barcode. Please make sure that the printer has good enough resolution to
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handle the chosen module width. </p>
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<p>For image backends is specifies the number of pixels to be used for the width
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of one module in the barcode. The module can be thought of as the thinnest line
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printed in the barcode. Each codeword is encoded 17 modules wide where there are
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4 black and 4 white separated areas.</p>
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<p>Even though most modern inkjet printers (2003 and later) can resolve modules
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down to 1 pixels it is recommended that for inkjet printers a module width of >=
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2 is used. </p>
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<p>For Postcript backend the module width specified the width in Postscript
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points (1 point = 1/72 inch).</p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$backend->SetModuleWidth(2);</span></pre></td></tr></table></div><p>
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</p>
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<p>
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</p><div class="tip" title="Tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3>
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<p>The size of the barcode image can be fine tuned by applying an overall
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scaling constant as specified with the method
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<code class="code">SetScale()</code>.</p>
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</div><p>
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</p>
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</div>
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<div class="sect3" title="SetHeight"><div class="titlepage"><div><div><h4 class="title"><a name="id2602757"></a>SetHeight</h4></div></div></div>
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<p><code class="code">SetHeight($aHeight)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Specified the height to width ratio for the individual rows in the barcode. By
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default the ratio is 3, which means that the height of the rows in the barcode
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is 3 times the module width. Most scanners can handle a factor between 2-5. You
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should very rarely have to change this parameter. </p>
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<p>The ratio is specified as an integer. </p>
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<p>One reason to change this to a smaller value is to make a barcode label take
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up less vertical space.</p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$backend->SetHeight(2);</span></pre></td></tr></table></div><p>
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</p>
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<p>
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</p><div class="caution" title="Caution" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Caution</h3>
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<p>Not all barcode scanners are good at handling very small ratios. This
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will also make the barcode more susceptible to damages.</p>
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</div><p>
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</p>
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</div>
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<div class="sect3" title="SetColor"><div class="titlepage"><div><div><h4 class="title"><a name="id2602882"></a>SetColor</h4></div></div></div>
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<p><code class="code">SetColor($aFrgColor,$aBkgColor)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Specify the foreground and background color for the barcode. </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$backend->SetColor( 'black', 'lightyellow');</span></pre></td></tr></table></div><p>
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</p>
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</div>
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<div class="sect3" title="ShowFrame"><div class="titlepage"><div><div><h4 class="title"><a name="id2602930"></a> ShowFrame</h4></div></div></div>
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<p><code class="code">ShowFrame($aFlg=true)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Draw a 1 pixel frame around the barcode. This is not recommended in production
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since it might disturb some scanners reading. This is only useful if you need a
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visual feedback on the boundaries for the image. </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">backend->SetFrame();</span></pre></td></tr></table></div><p>
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</p>
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</div>
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<div class="sect3" title="ShowText"><div class="titlepage"><div><div><h4 class="title"><a name="id2602973"></a>ShowText</h4></div></div></div>
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<p><code class="code">ShowText($aFlg=true)</code></p>
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<p>
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</p><div class="caution" title="Caution" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Caution</h3>
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<p>This is an extension specific to JpGraph. Human readable text is not
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part of the official PDF417 standard and hence this is disabled by
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default.. There are usually no problems of including this text but it is
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not recommended to do so in a production environment. This is mostly
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useful when debugging an application and to make it easer to see that
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the correct data is encoded as a barcode label.</p>
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</div><p>
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</p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Show human readable text of the encoded data underneath the barcode label. </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p>%%<p>
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</p>
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</div>
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<div class="sect3" title="SetFont"><div class="titlepage"><div><div><h4 class="title"><a name="id2602917"></a>SetFont</h4></div></div></div>
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<p><code class="code">SetFont($aFontFam,$aFontStyle,$aFontSize)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p> Specify the font for the human readable text underneath the barcode label. </p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$backend->SetFont( FF_ARIAL, FS_NORMAL, 8);</span></pre></td></tr></table></div><p>
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</p>
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</div>
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</div>
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<div class="sect2" title="Image backend methods"><div class="titlepage"><div><div><h3 class="title"><a name="id2603037"></a>Image backend methods</h3></div></div></div>
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<div class="sect3" title="SetImgFormat"><div class="titlepage"><div><div><h4 class="title"><a name="id2603067"></a> SetImgFormat</h4></div></div></div>
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<p><code class="code">SetImgFormat($aFormat)</code></p>
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<p><span class="bold"><strong>Purpose:</strong></span></p>
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<p>Specify image format. Possible values are </p>
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<p>
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</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
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<p><code class="code">'auto'</code></p>
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</li><li class="listitem">
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<p><code class="code">'png'</code></p>
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</li><li class="listitem">
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<p><code class="code">'jpeg'</code></p>
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</li><li class="listitem">
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<p><code class="code">'gif'</code></p>
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</li></ul></div><p>
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</p>
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<p><span class="bold"><strong>Example:</strong></span></p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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||
</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$backend->SetImgFormat('jpeg');</span></pre></td></tr></table></div><p>
|
||
</p>
|
||
</div>
|
||
</div>
|
||
<div class="sect2" title="Postscript backend methods"><div class="titlepage"><div><div><h3 class="title"><a name="id2603084"></a>Postscript backend methods</h3></div></div></div>
|
||
|
||
<p></p>
|
||
<div class="sect3" title="SetEPS($aFlg=true)"><div class="titlepage"><div><div><h4 class="title"><a name="id2603155"></a>SetEPS($aFlg=true)</h4></div></div></div>
|
||
|
||
<p><code class="code">SetEPS($aFlg=true)</code></p>
|
||
<p><span class="bold"><strong>Purpose:</strong></span></p>
|
||
<p>Format the output as Encapsulated Postcript. This adds a bounding box
|
||
information to the output and makes this format suitable to be included in other
|
||
postscript files. </p>
|
||
<p><span class="bold"><strong>Example:</strong></span></p>
|
||
<p>
|
||
</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
|
||
2
|
||
3
|
||
</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$encoder = new PDF417Barcode( $columns, $errlevel);
|
||
$backend = PDF417BackendFactory::Create( BACKEND_PS, $encoder);
|
||
$backend->SetEPS();</span></pre></td></tr></table></div><p>
|
||
</p>
|
||
</div>
|
||
</div>
|
||
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