HTMLRenderReport of BIRT adds a `file://`-like url to embedded images (instead of embedding them into the HTML)

问题

I have a BIRT report with an image in the master page.

My BIRT design file:

I embedded a png inside the report and it generated the following XML after the body tag:

  <list-property name="images">
      <structure>
          <property name="name">filename.png</property>
          <property name="type">image/png</property>
          <property name="data">
            BASE64 of the image
          </property>
      </structure>
   </list-property>

Then, I have included it into the master page, adding this element:

    <image id="828">
       <property name="source">embed</property>
       <property name="imageName">filename.png</property>
    </image>

Behaviours of my BIRT design file:

Then, If I run the preview from the BIRT designer it works great with both HTML and PDF output. If I render it using IPDFRenderOption (from my software) it generates the correct pdf fine. But if I use HTMLRenderOption, then the image is not embeded into the HTML report, but it is rendered with something like:

 <img src="file:/.../apache-tomcat-7.0.35/design11.png">

What I expect:

While I expected something like:

 <img src="data:image/png;base64,BASE64 STUFF THAT I PUT IN THE LIST-PROPERTIES ">

So, how can I let BIRT, when executed with HTMLRenderOption, to embed my image into the HTML file instead of creating a link to it?

回答1:

I solved this by adding two different images to the masterpage of the report:

Setting of the image in the PDF output:

Since the PDF is well rendered, I leaved the image as I wrote in the question, and I set off the visibility of this image in the HTML output

Setting of the image in the HTML output:

Then, in the master page, I added a new image. This time I haven't set it as embedded. Instead I set it as referenced by an URI. As URI I set the base64 URI that I need in my HTML output. Basically, I added to the XML of the report the following image:

<image id="1972">
    <list-property name="visibility">
        <structure>
            <property name="format">pdf</property>
            <expression name="valueExpr" type="javascript">true</expression>
        </structure>
    </list-property>
        <property name="source">url</property>
        <expression name="uri" type="constant">data:image/png;base64, BASE 64 OF MY PNG IMAGE</expression>
 </image>

I then set the image to be visibile only for the HTML output.

In this way BIRT renders an img tag with the URL i put in the XML, whatever it is. And thus, it puts the data:image/png;base64, BASE 64 OF MY PNG IMAGE as url. And thus it embeds the image in the HTML output.

Adding images from the database in your table:

BIRT supports the images inside blob fiels, and can manage in adding them to your report. To see how, see there: http://help.eclipse.org/helios/index.jsp?topic=%2Forg.eclipse.birt.doc%2Fbirt%2Flayout.5.7.html

If it does not works, you can manage inserting a dynamic value on your url, still without editing the scripts (but of course using a bit of Javascript to decide which column contains the data of teh image).

Here below the XML code of an image that reads the base64 value from a column:

  <image id="1974">
        <property name="source">url</property>
        <expression name="uri" type="javascript">"data:image/png;base64,"+row["BASE_64_PNG_COLUMN"]     </expression>
  </image>

来源：https://stackoverflow.com/questions/24308980/htmlrenderreport-of-birt-adds-a-file-like-url-to-embedded-images-instead-o

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