iText7表摘要

问题描述 投票:1回答:2

我使用iText7和pdfHTML插件将表格添加到PDF中。要设置表的可访问性,我想设置表的摘要。我在下面找到了同样的问题。但对此没有明确的答案。如何设置表格摘要。请指教。

iText7 508 Table Summary

c# itext7
2个回答
1
投票

谢谢布鲁诺。我用过C#。并且ProcessEnd方法应该如下更改。

public override void ProcessEnd(IElementNode element, ProcessorContext context)
    {
    base.ProcessEnd(element, context);
    IPropertyContainer elementResult = base.GetElementResult();
    if (elementResult is IAccessibleElement)
    {
    string summary= element.GetAttribute("summary"); //This is the summary="tbl summary" in HTML
    AccessibilityProperties properties = ((IAccessibleElement)elementResult).GetAccessibilityProperties();
    properties.AddAttributes(new PdfStructureAttributes("Table").AddEnumAttribute("Summary", summary));
    }
    }

要查看表格标题,您必须使用Adobe Acrobat Professional打开pdf。右键单击表并选择“编辑表摘要”。标题将显示在此处。


1
投票

我刚试过这个:

PdfDictionary attr = new PdfDictionary();
attr.put(new PdfName("Summary"), new PdfString("Info about the table"));
table.getAccessibilityProperties().addAttributes(new PdfStructureAttributes(attr));

这似乎可以解决问题。现在,您需要调整标记工作程序以确保在遇到table标记时执行此代码。

更新1:

我采用了以下HTML文件:

<body>
<table summary="some keys and values">
<thead>
<tr><th scope="col">KEY</th><th scope="col">VALUE</th></tr>
</thead>
<tbody>
<tr><td>Color</td><td>Blue</td></tr>
<tr><td>Shape</td><td>Rectangle</td></tr>
<tr><td>Description</td><td>Blue rectangle</td></tr>
</tbody>
</table>
</body>

我已将其转换为可访问的PDF文档,如下所示:

public void createPdf(String src, String dest) throws IOException {
    PdfWriter writer = new PdfWriter(dest,
        new WriterProperties().addUAXmpMetadata());
    PdfDocument pdf = new PdfDocument(writer);
    pdf.setTagged();
    pdf.getCatalog().setLang(new PdfString("en-US"));
    pdf.getCatalog().setViewerPreferences(
            new PdfViewerPreferences().setDisplayDocTitle(true));
    PdfDocumentInfo info = pdf.getDocumentInfo();
    info.setTitle("iText7 accessible tables");
    ConverterProperties properties = new ConverterProperties();
    FontProvider fontProvider = new DefaultFontProvider(false, true, false);
    properties.setFontProvider(fontProvider);
    HtmlConverter.convertToPdf(new FileInputStream(src), pdf, properties);
}

使用PAC3检查结果时,我得到以下结果:

enter image description here

到目前为止,从技术角度来看,PDF被认为是一个可访问的PDF / UA文件。

然后我做了“人”检查:表总结出现了吗?不幸的是,它没有,所以我查看了pdfHTML附加组件的代码,我没有找到任何对summary标签的table属性的引用。我认为在实现pdfHTML时会忘记它。

首先,我将编写一个自定义标记工作程序,负责添加摘要。完成后,我会要求iText Group实现summary属性,以便将其添加到下一个版本中。

更新2:

我改编了这样的例子:

public void createPdf(String src, String dest) throws IOException {
    PdfWriter writer = new PdfWriter(dest,
        new WriterProperties().addUAXmpMetadata());
    PdfDocument pdf = new PdfDocument(writer);
    pdf.setTagged();
    pdf.getCatalog().setLang(new PdfString("en-US"));
    pdf.getCatalog().setViewerPreferences(
            new PdfViewerPreferences().setDisplayDocTitle(true));
    PdfDocumentInfo info = pdf.getDocumentInfo();
    info.setTitle("iText7 accessible tables");
    ConverterProperties properties = new ConverterProperties();
    properties.setTagWorkerFactory(new AdaptedTagWorkerFactory());
    FontProvider fontProvider = new DefaultFontProvider(false, true, false);
    properties.setFontProvider(fontProvider);
    HtmlConverter.convertToPdf(new FileInputStream(src), pdf, properties);
}

class AdaptedTagWorkerFactory extends DefaultTagWorkerFactory {
    @Override
    public ITagWorker getCustomTagWorker(IElementNode tag, ProcessorContext context) {
        if(tag.name().equals("table")){
            return new TableWithSummaryTagWorker(tag, context);
        }
        return null;
     }
}

class TableWithSummaryTagWorker extends TableTagWorker {

    private String summary = null;

    public TableWithSummaryTagWorker(IElementNode element, ProcessorContext context) {
        super(element, context);
    }

    @Override
    public void processEnd(IElementNode element, ProcessorContext context) {
        super.processEnd(element, context);
        summary = element.getAttribute("summary");
        if (summary != null) {
            Table table = (Table) super.getElementResult();
            PdfDictionary attr = new PdfDictionary();
            attr.put(new PdfName("Summary"), new PdfString(summary));
            table.getAccessibilityProperties().addAttributes(new PdfStructureAttributes(attr));
        }
    }
}

我通过PAC3运行它,它仍然验证为PDF / UA,但它没有提到任何地方的表摘要。当我查看PDF时,我现在可以看到摘要:

enter image description here

我现在将与iText Group分享此信息,并要求他们检查我的解决方案是否正确(如果这不能解决您的问题,请添加评论)。如果确实如此,那么从iText 7.1.4开始实现这一点的可能性很大。

更新3:

我根据OP提供的答案调整了我的代码。 OP的代码中有一个错误。在该代码中,/Summary作为PDF名称添加,而它应该是PDF字符串。

public void createPdf(String src, String dest) throws IOException {
    PdfWriter writer = new PdfWriter(dest,
        new WriterProperties().addUAXmpMetadata());
    PdfDocument pdf = new PdfDocument(writer);
    pdf.setTagged();
    pdf.getCatalog().setLang(new PdfString("en-US"));
    pdf.getCatalog().setViewerPreferences(
            new PdfViewerPreferences().setDisplayDocTitle(true));
    PdfDocumentInfo info = pdf.getDocumentInfo();
    info.setTitle("iText7 accessibility example");
    ConverterProperties properties = new ConverterProperties();
    properties.setTagWorkerFactory(new AdaptedTagWorkerFactory());
    FontProvider fontProvider = new DefaultFontProvider(false, true, false);
    properties.setFontProvider(fontProvider);
    HtmlConverter.convertToPdf(new FileInputStream(src), pdf, properties);
}

class AdaptedTagWorkerFactory extends DefaultTagWorkerFactory {
    @Override
    public ITagWorker getCustomTagWorker(IElementNode tag, ProcessorContext context) {
        if(tag.name().equals("table")){
            return new TableWithSummaryTagWorker(tag, context);
        }
        return null;
     }
}

class TableWithSummaryTagWorker extends TableTagWorker {

    private String summary = null;

    public TableWithSummaryTagWorker(IElementNode element, ProcessorContext context) {
        super(element, context);
    }

    @Override
    public void processEnd(IElementNode element, ProcessorContext context) {
        super.processEnd(element, context);
        IPropertyContainer elementResult = super.getElementResult();
        summary = element.getAttribute("summary");
        if (summary != null && elementResult instanceof IAccessibleElement) {
            AccessibilityProperties properties = ((IAccessibleElement)elementResult).getAccessibilityProperties();
            properties.addAttributes(new PdfStructureAttributes("Table").addTextAttribute("Summary", summary));
        }
    }
}

现在,当您检查结果时,您会收到以下报告:

enter image description here

如您所见,Summary测试通过。

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