python - QWebEngineView update with pdf path

Question

I have a QtWebEngineWidgets showing some pdf files. I want to change pdf and force QtWebEngineView display automatically and dynamically. The problem I get is the QtWebEngineWidgets does not update, incapabile to display when pdf file path changes.

class PdfReport(QtWebEngineWidgets.QWebEngineView):
    PDFJS = 'file:///pdfjs/web/viewer.html'
    def __init__(self, parent=None):
        super(PdfReport, self).__init__(parent)
        self.PDF = 'file:///Technicalreport/file0.pdf'
        self.load(QtCore.QUrl.fromUserInput('%s?file=%s' % (PDFJS, self.PDF))) 

    @QtCore.pyqtSlot(int)    
    def index_load(self, _index):
        self._index = _index
        self.PDF = pdfpath(self._index)

Outer function:

def pdfpath(index):
    if index == -1:
        PDF = 'file:///Technicalreport/file0.pdf'
    else:
        PDF = 'file:///Technicalreport/file%d.pdf' %index
    return PDF

tried to test function and returns as expected:

for i in range(3):
    print(pdfpath(i), type(pdfpath(i)))

file:///Technicalreport/file0.pdf <class 'str'>
file:///Technicalreport/file1.pdf <class 'str'>
file:///Technicalreport/file2.pdf <class 'str'>

Yes pdf files 'file0', 'file1' and 'file2' exist:

When it runs gets this error:

TypeError: 'module' object is not callable

Update:

import sys
from PyQt5 import QtCore, QtWidgets, QtWebEngineWidgets

PDFJS = 'file:///pdfjs/web/viewer.html'
PDF = 'file:///Technicalreport/file0.pdf'

def pdfpath(index):
    if index == -1:
        PDF = 'file:///Technicalreport/file0.pdf'
    else:
        PDF = 'file:///Technicalreport/file%d.pdf' %index
    return PDF


class Foo(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Foo, self).__init__(parent)
        self.setGeometry(QtCore.QRect(200, 100, 800, 800))

        self.pdf = Window()
        self.com = Widget()
        self.lay = QtWidgets.QVBoxLayout(self)
        self.lay.addWidget(self.pdf)
        self.lay.addWidget(self.com)

        self.com.IndexChanged.connect(self.pdf.index_load)


class Window(QtWebEngineWidgets.QWebEngineView):

    def __init__(self, parent=None):
        super(Window, self).__init__(parent)
        self.PDF = PDF
        self.load(QtCore.QUrl.fromUserInput('%s?file=%s' % (PDFJS, self.PDF)))            

    @QtCore.pyqtSlot(int)    
    def index_load(self, _index):
        self._index = _index
        self.PDF = pdfpath(self._index)
        print(self.PDF,'=', self._index)



class Widget(QtWidgets.QWidget):
    IndexChanged = QtCore.pyqtSignal(int)
    def __init__(self, parent=None):
        QtWidgets.QWidget.__init__(self, parent)
        self.setLayout(QtWidgets.QVBoxLayout())
        self.combo = QtWidgets.QComboBox(self)
        self.layout().addWidget(self.combo)
        self.combo.addItems(["item1", "item2", "item3"])
        self.combo.setMinimumWidth(150)
        self.combo.activated[int].connect(self.onActivatedIndex)

    @QtCore.pyqtSlot(int)
    def onActivatedIndex(self, index):
        self.IndexChanged.emit(index)


if __name__ == '__main__':

    app = QtWidgets.QApplication(sys.argv)
    window = Foo()
    window.setGeometry(600, 50, 800, 600)
    window.show()
    sys.exit(app.exec_())

Display:

Answer 1

Assuming that the other parts of your program work correctly, the problem is that you are only updating a variable but you are not loading the new url, so the solution is:

class PdfReport(QtWebEngineWidgets.QWebEngineView):
    PDFJS = "file:///pdfjs/web/viewer.html"

    def __init__(self, parent=None):
        super(PdfReport, self).__init__(parent)
        self.load_pdf("file:///Technicalreport/file0.pdf")

    def load_pdf(self, pdf):
        self.load(
            QtCore.QUrl.fromUserInput("%s?file=%s" % (PdfReport.PDFJS, pdf))
        )

The problem in your case is that you are creating the path incorrectly because you must use an absolute path and not relative as in your case. Considering the above the solution is:

import os
import sys
from PyQt5 import QtCore, QtWidgets, QtWebEngineWidgets

CURRENT_DIR = os.path.dirname(os.path.realpath(__file__))

PDFJS = QtCore.QUrl.fromLocalFile(
    os.path.join(CURRENT_DIR, "pdfjs/web/viewer.html")
).toString()


def pdfpath(index):
    filename = ""
    if index == -1:
        filename = "Technicalreport/file0.pdf"
    else:
        filename = "Technicalreport/file%d.pdf" % index
    return os.path.join(CURRENT_DIR, filename)


class PdfReport(QtWebEngineWidgets.QWebEngineView):
    def load_pdf(self, filename):
        url = QtCore.QUrl.fromLocalFile(filename).toString()
        self.load(QtCore.QUrl.fromUserInput("%s?file=%s" % (PDFJS, url)))

    def sizeHint(self):
        return QtCore.QSize(640, 480)

    @QtCore.pyqtSlot(int)
    def index_load(self, index):
        path = pdfpath(index)
        self.load_pdf(path)


class Widget(QtWidgets.QWidget):
    indexChanged = QtCore.pyqtSignal(int)

    def __init__(self, parent=None):
        super(Widget, self).__init__(parent)
        self.combo = QtWidgets.QComboBox()
        self.combo.addItems(["item1", "item2", "item3"])
        self.combo.setMinimumWidth(150)
        self.combo.activated[int].connect(self.indexChanged)

        lay = QtWidgets.QVBoxLayout(self)
        lay.addWidget(self.combo)

        self.setSizePolicy(
            QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Maximum
        )


class Foo(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super(Foo, self).__init__(parent)

        self.pdf = PdfReport()
        self.com = Widget()

        self.com.indexChanged.connect(self.pdf.index_load)
        self.pdf.index_load(-1)

        lay = QtWidgets.QVBoxLayout(self)
        lay.addWidget(self.pdf)
        lay.addWidget(self.com)


if __name__ == "__main__":

    app = QtWidgets.QApplication(sys.argv)
    w = Foo()
    w.show()
    sys.exit(app.exec_())

├── main.py
├── pdfjs
│?? ├── build
│?? │?? └── ...
│?? ├── LICENSE
│?? └── web
│??     ├── ...
│??     ├── viewer.html
│??     └── ...
└── Technicalreport
    ├── file0.pdf
    ├── file1.pdf
    └── file2.pdf