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Convert HTML to PDF

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  • JoeCFDJ Offline
    JoeCFDJ Offline
    JoeCFD
    wrote on last edited by JoeCFD
    #6

    Another way is to convert the web page to a xml file which can be used to make web pages. You may be able to find tools to do that. Then it may be easier to convert xml file to PDF or QTextDocument.

    1 Reply Last reply
    0
    • M Marcus Barnet

      Thank you! Yes, I could try! I have all the html code store into a QString html_page variable.

      What is the fastest way to convert it to QTextDocument?

      QTextDocument doc;
      doc.setHtml(html_page );
      

      The web page is formatted to fit in a A4 format as it is.
      I couldn't find any simple code to understand how to use QPdfWriter, by the way!

      JonBJ Offline
      JonBJ Offline
      JonB
      wrote on last edited by
      #7

      @Marcus-Barnet
      Be aware that QTextDocument's support for HTML is "limited". To that subset specified by Qt.

      When you talk about

      Unfortunately, I can't get rid of the HTML part since the webpage is formatted in a very specific way.

      it makes me think you may need full, unadulterated HTML support. Like that in a web browser.

      You can use the older Qt webkit that you mention. However, that is no longer supplied with Qt, and you'll likely have to build it yourself. If you do not want to do that, are you aware that Qt replaced that with Qt WebEngine, which can also be used to display a web page and print it, including to PDF?

      M 1 Reply Last reply
      0
      • M Marcus Barnet

        Thank you! Yes, I could try! I have all the html code store into a QString html_page variable.

        What is the fastest way to convert it to QTextDocument?

        QTextDocument doc;
        doc.setHtml(html_page );
        

        The web page is formatted to fit in a A4 format as it is.
        I couldn't find any simple code to understand how to use QPdfWriter, by the way!

        artwawA Offline
        artwawA Offline
        artwaw
        wrote on last edited by
        #8

        @Marcus-Barnet setHTML() is a way to go.
        QPdfWriter operates as usual printer, difference is that it produces well formed PDF document.

        The way to do it is use QTextDocument::drawContents() method, like on the printer. You might need to take care of setting the resolution of the "printer" and so on (when you notice that image is scaled up/down, etc, my usual setting is 300dpi).

        If that works then it works and you have less work.
        It it does not... Like @JonB said, only cumbersome solutions like webkit or QtWebEngine.

        On that note I fully endorse your decision of using lightweight webkit over a heavy cow of web engine. For this particular task should suffice.
        But I hope you don't have to use any of them.

        For more information please re-read.

        Kind Regards,
        Artur

        1 Reply Last reply
        1
        • JonBJ JonB

          @Marcus-Barnet
          Be aware that QTextDocument's support for HTML is "limited". To that subset specified by Qt.

          When you talk about

          Unfortunately, I can't get rid of the HTML part since the webpage is formatted in a very specific way.

          it makes me think you may need full, unadulterated HTML support. Like that in a web browser.

          You can use the older Qt webkit that you mention. However, that is no longer supplied with Qt, and you'll likely have to build it yourself. If you do not want to do that, are you aware that Qt replaced that with Qt WebEngine, which can also be used to display a web page and print it, including to PDF?

          M Offline
          M Offline
          Marcus Barnet
          wrote on last edited by
          #9

          @JonB said in Convert HTML to PDF:

          @Marcus-Barnet
          Be aware that QTextDocument's support for HTML is "limited". To that subset specified by Qt.

          When you talk about

          Unfortunately, I can't get rid of the HTML part since the webpage is formatted in a very specific way.

          it makes me think you may need full, unadulterated HTML support. Like that in a web browser.

          You can use the older Qt webkit that you mention. However, that is no longer supplied with Qt, and you'll likely have to build it yourself. If you do not want to do that, are you aware that Qt replaced that with Qt WebEngine, which can also be used to display a web page and print it, including to PDF?

          Yes, it's for this reason that I skipped the QTextDocument months ago.
          I remember that someone in this forum (may be you) told me that is supports only a limited set of HTML tags while my webpage is highly formatted.

          I do not think I have the skills to be able to build my myself the package, may be I should try Qt WebEngine, I need to check if there is any code example about that on google.

          JonBJ artwawA 2 Replies Last reply
          0
          • M Marcus Barnet

            @JonB said in Convert HTML to PDF:

            @Marcus-Barnet
            Be aware that QTextDocument's support for HTML is "limited". To that subset specified by Qt.

            When you talk about

            Unfortunately, I can't get rid of the HTML part since the webpage is formatted in a very specific way.

            it makes me think you may need full, unadulterated HTML support. Like that in a web browser.

            You can use the older Qt webkit that you mention. However, that is no longer supplied with Qt, and you'll likely have to build it yourself. If you do not want to do that, are you aware that Qt replaced that with Qt WebEngine, which can also be used to display a web page and print it, including to PDF?

            Yes, it's for this reason that I skipped the QTextDocument months ago.
            I remember that someone in this forum (may be you) told me that is supports only a limited set of HTML tags while my webpage is highly formatted.

            I do not think I have the skills to be able to build my myself the package, may be I should try Qt WebEngine, I need to check if there is any code example about that on google.

            JonBJ Offline
            JonBJ Offline
            JonB
            wrote on last edited by JonB
            #10

            @Marcus-Barnet
            Note that @artwaw has just posted before you. He suggests that QPdfWriter (didn't yet exist when I did my stuff for this a few years ago) is preferable to WebKit/Engine, on the cumbersome-ness front. He may well know what he is talking about! But for QTextDocument I'm not sure it will support the raw HTML you seem to have? Maybe @artwaw will comment further?

            artwawA 1 Reply Last reply
            0
            • JonBJ JonB

              @Marcus-Barnet
              Note that @artwaw has just posted before you. He suggests that QPdfWriter (didn't yet exist when I did my stuff for this a few years ago) is preferable to WebKit/Engine, on the cumbersome-ness front. He may well know what he is talking about! But for QTextDocument I'm not sure it will support the raw HTML you seem to have? Maybe @artwaw will comment further?

              artwawA Offline
              artwawA Offline
              artwaw
              wrote on last edited by
              #11

              @JonB /me will.
              It all depends on the document. Supported subset is documented here: https://doc.qt.io/qt-5/richtext-html-subset.html

              If that doesn't work, well... Further up I posted links to binaries of QtWebkit, just download and put into your Qt tree. As for printing - I'd need about half an hour to dig out how I did it with webkit in the past.

              For more information please re-read.

              Kind Regards,
              Artur

              1 Reply Last reply
              0
              • M Marcus Barnet

                @JonB said in Convert HTML to PDF:

                @Marcus-Barnet
                Be aware that QTextDocument's support for HTML is "limited". To that subset specified by Qt.

                When you talk about

                Unfortunately, I can't get rid of the HTML part since the webpage is formatted in a very specific way.

                it makes me think you may need full, unadulterated HTML support. Like that in a web browser.

                You can use the older Qt webkit that you mention. However, that is no longer supplied with Qt, and you'll likely have to build it yourself. If you do not want to do that, are you aware that Qt replaced that with Qt WebEngine, which can also be used to display a web page and print it, including to PDF?

                Yes, it's for this reason that I skipped the QTextDocument months ago.
                I remember that someone in this forum (may be you) told me that is supports only a limited set of HTML tags while my webpage is highly formatted.

                I do not think I have the skills to be able to build my myself the package, may be I should try Qt WebEngine, I need to check if there is any code example about that on google.

                artwawA Offline
                artwawA Offline
                artwaw
                wrote on last edited by artwaw
                #12

                @Marcus-Barnet Got it. Not overly complicated.

                I write this under the assumption that you do not need to display the page.
                Once you have QtWebkit installed, you take QWebPage, usual QWebPage page; or something.

                Important concept with webkit is that (in our context) page manipulation like printing is not done on QWebPage object but on frames. Each QWebPage has at least one frame accessible via mainFrame() method. That is the key.

                So, to set the content we do page->mainFrame()->setHtml(QString html);
                To print, we need to setup the printer (plot twist! NOT QPdfWriter) and simply call page->mainFrame()->print(QPrinter *printer);
                To print to pdf from QPrinter you need to call during the setup QPrinter::setOutputFormat(QPrinter::PdfFormat); and QPrinter::setOutputFileName(QString fname);

                Documentation is here:

                https://qtwebkit.github.io/doc/qtwebkit/qwebpage.html
                https://qtwebkit.github.io/doc/qtwebkit/qwebframe.htm
                https://doc.qt.io/qt-5/qprinter.html

                At least that's what I did in my last project and I have to say it worked rather well.

                The reason I opt so often towards QtWebkit is that for solutions like this it is really lightweight and fast. Say, for headless processing or static html. For full fledged web applications it might be not enough but for like the above? Ideal.

                Have fun!

                Edit: I corrected calls to QWebFrame methods since I forgot that mainFrame() returns pointer.

                For more information please re-read.

                Kind Regards,
                Artur

                1 Reply Last reply
                1
                • M Offline
                  M Offline
                  Marcus Barnet
                  wrote on last edited by
                  #13

                  Thank you a lot! I'll check everything this evening and I'll let you know if it worked!

                  1 Reply Last reply
                  0
                  • JonBJ Offline
                    JonBJ Offline
                    JonB
                    wrote on last edited by JonB
                    #14

                    You can do the same as @artwaw's approach of using PDF printer from QWebEnginePage. Absolutely nothing wrong with QtWebKit QWebPage. Just I don't compile anything Qt, just so you know if you have any compile problems.

                    artwawA 1 Reply Last reply
                    0
                    • JonBJ JonB

                      You can do the same as @artwaw's approach of using PDF printer from QWebEnginePage. Absolutely nothing wrong with QtWebKit QWebPage. Just I don't compile anything Qt, just so you know if you have any compile problems.

                      artwawA Offline
                      artwawA Offline
                      artwaw
                      wrote on last edited by
                      #15

                      @JonB side note and part explanation: for me QWebEngine is a no go on Windows as it requires Microsoft environment. I never managed to set it up properly, for some reason I saw my programs working well on mingw failing to compile I checked no further. Call me spoiled but...

                      For more information please re-read.

                      Kind Regards,
                      Artur

                      1 Reply Last reply
                      1
                      • JoeCFDJ Offline
                        JoeCFDJ Offline
                        JoeCFD
                        wrote on last edited by
                        #16

                        https://doc.qt.io/qt-5/qtwebengine-webenginewidgets-html2pdf-example.html
                        does this one help?

                        1 Reply Last reply
                        0
                        • M Offline
                          M Offline
                          Marcus Barnet
                          wrote on last edited by
                          #17

                          Thank you to all, guys, for your support!

                          Unfortunately, I think using qtwebkit requires some skills, since I downloaded this one: https://download.qt.io/snapshots/ci/qtwebkit/5.212/latest/qtwebkit/qtwebkit-Windows-Windows_10-MSVC2019-Windows-Windows_10-X86_64.7z and I got a folder that I moved to my QT directory:

                          C:\Qt\5.15.0\qtwebkit-Windows-Windows_10-MSVC2019-Windows-Windows_10-X86_64
                          
                          08/06/2021  22:50    <DIR>          .
                          08/06/2021  22:50    <DIR>          ..
                          08/06/2021  22:50    <DIR>          bin
                          08/06/2021  22:50    <DIR>          include
                          08/06/2021  22:50    <DIR>          lib
                          24/09/2020  14:15    <DIR>          mkspecs
                          08/06/2021  22:50    <DIR>          qml
                          

                          and I do not know how to proceed from this step. I tried to search on the forum, but I didn't found any topic about this (only one, but it was for Linux while I'm on Windows 10).
                          My current program uses msvc2019_64.

                          I can't understand how I can build this package.

                          artwawA 1 Reply Last reply
                          0
                          • M Marcus Barnet

                            Thank you to all, guys, for your support!

                            Unfortunately, I think using qtwebkit requires some skills, since I downloaded this one: https://download.qt.io/snapshots/ci/qtwebkit/5.212/latest/qtwebkit/qtwebkit-Windows-Windows_10-MSVC2019-Windows-Windows_10-X86_64.7z and I got a folder that I moved to my QT directory:

                            C:\Qt\5.15.0\qtwebkit-Windows-Windows_10-MSVC2019-Windows-Windows_10-X86_64
                            
                            08/06/2021  22:50    <DIR>          .
                            08/06/2021  22:50    <DIR>          ..
                            08/06/2021  22:50    <DIR>          bin
                            08/06/2021  22:50    <DIR>          include
                            08/06/2021  22:50    <DIR>          lib
                            24/09/2020  14:15    <DIR>          mkspecs
                            08/06/2021  22:50    <DIR>          qml
                            

                            and I do not know how to proceed from this step. I tried to search on the forum, but I didn't found any topic about this (only one, but it was for Linux while I'm on Windows 10).
                            My current program uses msvc2019_64.

                            I can't understand how I can build this package.

                            artwawA Offline
                            artwawA Offline
                            artwaw
                            wrote on last edited by
                            #18

                            @Marcus-Barnet It should be already build. Just reopen QtCreator and add Qt += webkit in your .pro file.
                            I have also Qt += webkitwidgets but I don't think you need them.

                            At any rate you can then do #include <QWebPage> in the header files.

                            For more information please re-read.

                            Kind Regards,
                            Artur

                            1 Reply Last reply
                            1
                            • M Offline
                              M Offline
                              Marcus Barnet
                              wrote on last edited by
                              #19

                              where should I copy the files contained in the archive I downloaded?

                              This is the path where my qmake is:

                              C:\Qt\5.15.0\msvc2019_64\bin\qmake.exe
                              

                              should I copy the content of:

                              C:\Qt\5.15.0\qtwebkit-Windows-Windows_10-MSVC2019-Windows-Windows_10-X86_64
                              08/06/2021  22:50    <DIR>          .
                              08/06/2021  22:50    <DIR>          ..
                              08/06/2021  22:50    <DIR>          bin
                              08/06/2021  22:50    <DIR>          include
                              08/06/2021  22:50    <DIR>          lib
                              24/09/2020  14:15    <DIR>          mkspecs
                              08/06/2021  22:50    <DIR>          qml
                              

                              in this directory?

                              C:\Qt\5.15.0\msvc2019_64
                              
                              19/07/2020  21:36    <DIR>          .
                              19/07/2020  21:36    <DIR>          ..
                              29/07/2020  10:15    <DIR>          bin
                              19/07/2020  21:34    <DIR>          doc
                              19/07/2020  21:36    <DIR>          include
                              19/07/2020  21:39    <DIR>          lib
                              19/07/2020  21:34    <DIR>          mkspecs
                              19/07/2020  21:34    <DIR>          phrasebooks
                              19/07/2020  21:36    <DIR>          plugins
                              19/07/2020  21:36    <DIR>          qml
                              19/07/2020  21:36    <DIR>          resources
                              19/07/2020  21:36    <DIR>          translations
                              

                              Sorry for the stupid question, but I can't understand how to use these files.
                              Usually, in linux, there is /src and /lib folders that you can pass as parameter to the compiler.

                              artwawA 1 Reply Last reply
                              0
                              • M Marcus Barnet

                                where should I copy the files contained in the archive I downloaded?

                                This is the path where my qmake is:

                                C:\Qt\5.15.0\msvc2019_64\bin\qmake.exe
                                

                                should I copy the content of:

                                C:\Qt\5.15.0\qtwebkit-Windows-Windows_10-MSVC2019-Windows-Windows_10-X86_64
                                08/06/2021  22:50    <DIR>          .
                                08/06/2021  22:50    <DIR>          ..
                                08/06/2021  22:50    <DIR>          bin
                                08/06/2021  22:50    <DIR>          include
                                08/06/2021  22:50    <DIR>          lib
                                24/09/2020  14:15    <DIR>          mkspecs
                                08/06/2021  22:50    <DIR>          qml
                                

                                in this directory?

                                C:\Qt\5.15.0\msvc2019_64
                                
                                19/07/2020  21:36    <DIR>          .
                                19/07/2020  21:36    <DIR>          ..
                                29/07/2020  10:15    <DIR>          bin
                                19/07/2020  21:34    <DIR>          doc
                                19/07/2020  21:36    <DIR>          include
                                19/07/2020  21:39    <DIR>          lib
                                19/07/2020  21:34    <DIR>          mkspecs
                                19/07/2020  21:34    <DIR>          phrasebooks
                                19/07/2020  21:36    <DIR>          plugins
                                19/07/2020  21:36    <DIR>          qml
                                19/07/2020  21:36    <DIR>          resources
                                19/07/2020  21:36    <DIR>          translations
                                

                                Sorry for the stupid question, but I can't understand how to use these files.
                                Usually, in linux, there is /src and /lib folders that you can pass as parameter to the compiler.

                                artwawA Offline
                                artwawA Offline
                                artwaw
                                wrote on last edited by
                                #20

                                @Marcus-Barnet yes. exactly there, all folders' content to the respective folders.

                                For more information please re-read.

                                Kind Regards,
                                Artur

                                1 Reply Last reply
                                1
                                • M Offline
                                  M Offline
                                  Marcus Barnet
                                  wrote on last edited by
                                  #21

                                  thank you, I did as you suggested and now I get no errors when I try to call QWebPage.

                                  Later, this evening, I will try to use it for the PDF and I will update you.

                                  1 Reply Last reply
                                  2
                                  • M Offline
                                    M Offline
                                    Marcus Barnet
                                    wrote on last edited by Marcus Barnet
                                    #22

                                    I tried to convert the html to pdf, it works fine even if this process doesn't include a PNG image which is included in the HTML page.

                                    Unfortunately, this image is very important since it is a logo which must be included also in the PDF file. (I use the <img> tag to insert the image)
                                    Is there any specific reason for not including the image?

                                    Moreover, I noticed that the table borders are displayed in grey color while they should be black.
                                    This is the code I'm using:

                                      ```
                                           QWebPage page;
                                           page.mainFrame()->setHtml(html_scheda);
                                    
                                           QPrinter printer(QPrinter::HighResolution);
                                           printer.setOrientation(QPrinter::Portrait);
                                           printer.setOutputFormat(QPrinter::PdfFormat);
                                           printer.setPaperSize(QPrinter::A4);
                                           printer.setPageMargins(QMarginsF(5, 5, 5, 5));
                                           QString fileName = "C:/folder/test.pdf";
                                           printer.setOutputFileName(fileName);
                                    
                                           page.mainFrame()->print(&printer);
                                    
                                    artwawA 1 Reply Last reply
                                    0
                                    • M Marcus Barnet

                                      I tried to convert the html to pdf, it works fine even if this process doesn't include a PNG image which is included in the HTML page.

                                      Unfortunately, this image is very important since it is a logo which must be included also in the PDF file. (I use the <img> tag to insert the image)
                                      Is there any specific reason for not including the image?

                                      Moreover, I noticed that the table borders are displayed in grey color while they should be black.
                                      This is the code I'm using:

                                        ```
                                             QWebPage page;
                                             page.mainFrame()->setHtml(html_scheda);
                                      
                                             QPrinter printer(QPrinter::HighResolution);
                                             printer.setOrientation(QPrinter::Portrait);
                                             printer.setOutputFormat(QPrinter::PdfFormat);
                                             printer.setPaperSize(QPrinter::A4);
                                             printer.setPageMargins(QMarginsF(5, 5, 5, 5));
                                             QString fileName = "C:/folder/test.pdf";
                                             printer.setOutputFileName(fileName);
                                      
                                             page.mainFrame()->print(&printer);
                                      
                                      artwawA Offline
                                      artwawA Offline
                                      artwaw
                                      wrote on last edited by
                                      #23

                                      @Marcus-Barnet from documentation: External objects referenced in the content are located relative to baseUrl. I'd search in that direction.

                                      For more information please re-read.

                                      Kind Regards,
                                      Artur

                                      M 1 Reply Last reply
                                      0
                                      • artwawA artwaw

                                        @Marcus-Barnet from documentation: External objects referenced in the content are located relative to baseUrl. I'd search in that direction.

                                        M Offline
                                        M Offline
                                        Marcus Barnet
                                        wrote on last edited by
                                        #24

                                        @artwaw said in Convert HTML to PDF:

                                        @Marcus-Barnet from documentation: External objects referenced in the content are located relative to baseUrl. I'd search in that direction.

                                        The problem is that the logo is loaded from the network, so I do not know what kind of base_url I should specify.

                                        This is the HTML where I load the picture:

                                        html_scheda = "<table align=\"center\" border=\"0\" style=\"border-collapse: collapse; width: 21cm; height: 29 cm;\"> <tbody> <tr> <td style=\"width: 100%;\"> <table border=\"0\" style=\"height: 146px; width: 100%; border-collapse: collapse; margin-left: auto; margin-right: auto;\"> <tbody> <tr style=\"height: 0px;\"> <td style=\"width: 50%; height: 146px; text-align: center;\" rowspan=\"4\"><img width=\"200\" align=\"center\" src=\"http://www.robo-dyne.com/pics/pump_logo.png\" alt=\"\" /></td>
                                        

                                        What should I use as baseurl in this situation?

                                        artwawA 2 Replies Last reply
                                        0
                                        • A Offline
                                          A Offline
                                          AlexMaly
                                          wrote on last edited by
                                          #25

                                          We had the same problem and while webkit is viable option it does not support everything we needed.
                                          We tried a few options, but the best result was produced with using chrome:
                                          It can do it in headless mode
                                          google-chrome --headless --disable-gpu --print-to-pdf=file1.pdf http://www.example.com/

                                          So if you could make sure chrome is installed on your system, this would be an approach I recommend.

                                          M 1 Reply Last reply
                                          0

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