采用chrome headless方案

为什么要采用Chrome headless

因为wkhtmltopdf内置的为qt的webkit，已经很久不更新了，很多css3以及html5都支持不友好。

Chrome官方提供的页面转换为PDF的接口

https://chromedevtools.github.io/devtools-protocol/tot/Page#method-printToPDF

命令行方式

chrome --headless --print-to-pdf=path/to/file.pdf https://example.com

参考：HTML to PDF conversion using Chrome pdfium?

NodeJS扩展

html-pdf-chrome HTML to PDF converter via Chrome/Chromium.

PHP扩展

chrome-html-to-pdf Converts HTML to PDF using Google Chrome

Chrome命令行参数列表

List of Chromium Command Line Switches

采用Qt的Webkit(PyQt5)

由于当前的chrome转换存在BUG，转换大文件时内存消耗特别大，生成的文件也比较大，测试了10多种方法后，最后决定采用PyQt5来做

#!/usr/bin/env python3

import sys
import argparse

from PyQt5.QtCore import QUrl, QMarginsF
from PyQt5.QtGui import QPageLayout, QPageSize
from PyQt5.QtWebEngineWidgets import QWebEngineView
from PyQt5.QtWidgets import QApplication


class PrinterView(QWebEngineView):
    def __init__(self, url, filename, do_preview, parent=None):
        super(PrinterView, self).__init__(parent)
        self.do_preview = do_preview
        self.setUrl(QUrl(url))
        self.setZoomFactor(1)
        self.loadFinished.connect(self.load_finished)
        self.filename = filename

    def load_finished(self):
        if self.do_preview:
            self.show()
        else:
            pageLayout = QPageLayout(QPageSize(QPageSize.A5), QPageLayout.Portrait,
                                     QMarginsF(0, 0, 0, 0))
            self.page().printToPdf(self.filename, pageLayout)
            self.page().pdfPrintingFinished.connect(on_pdf_finished)


def on_pdf_finished(result):
    if result:
        print(result)
        QApplication.exit()
    else:
        QApplication.exit(1)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    parser = argparse.ArgumentParser()
    parser.add_argument("--url", "-i", help="Input URL (http://example.com, file:///home/user/example.html, ...)",
                        required=True)
    parser.add_argument("--output", "-o", help="Write pdf to this file", required=True)
    parser.add_argument("--preview", "-p", help="Open preview", action="store_true")
    args = parser.parse_args()
    a = PrinterView(args.url, args.output, args.preview)
    sys.exit(app.exec_())

　采用qt打印

import sys
import argparse

from PyQt5.QtCore import QUrl, QMarginsF
from PyQt5.QtGui import QPageLayout, QPageSize
from PyQt5.QtWebEngineWidgets import QWebEngineView, QWebEnginePage, QWebEngineProfile
from PyQt5.QtWidgets import QApplication
from PyQt5.QtPrintSupport import QPrinter, QPrintDialog


class PrinterView(QWebEngineView):
    def __init__(self, url, filename, do_preview, parent=None):
        self.printer = QPrinter()
        self.printer.setPageSize(QPrinter.A5)
        self.printer.setOrientation(QPrinter.Portrait)
        self.printer.setOutputFormat(QPrinter.PdfFormat)
        self.printer.setOutputFileName(filename)
        self.printer.setPageMargins(0, 0, 0, 0, QPrinter.Millimeter)
        super(PrinterView, self).__init__(parent)
        self.do_preview = do_preview
        self.page().profile().setHttpCacheMaximumSize(5 * 1024 * 1024 * 1024)
        self.page().profile().setHttpCacheType(QWebEngineProfile.MemoryHttpCache)
        self.setUrl(QUrl(url))
        self.setZoomFactor(1)
        self.loadFinished.connect(self.load_finished2)
        self.filename = filename

    def load_finished(self):
        if self.do_preview:
            self.show()
        else:
            pageLayout = QPageLayout(QPageSize(QPageSize.A5), QPageLayout.Portrait,
                                     QMarginsF(0, 0, 0, 0))
            self.page().printToPdf(self.filename, pageLayout)
            self.page().pdfPrintingFinished.connect(on_pdf_finished)

    def load_finished2(self):
        self.show()
        self.page().print(self.printer, on_pdf_finished)


def on_pdf_finished(result):
    if result:
        print(result)
        QApplication.exit()
    else:
        QApplication.exit(1)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    parser = argparse.ArgumentParser()
    parser.add_argument("--url", "-i", help="Input URL (http://example.com, file:///home/user/example.html, ...)",
                        required=True)
    parser.add_argument("--output", "-o", help="Write pdf to this file", required=True)
    parser.add_argument("--preview", "-p", help="Open preview", action="store_true")
    args = parser.parse_args()
    a = PrinterView(args.url, args.output, args.preview)
    sys.exit(app.exec_())

使用firefox的pdf

slimer-html-pdf – convert any HTML document to PDF format using slimerjs (Gecko)

大文件合并(Python)

 def on_pdf_finished(self, result):
        if result:
            print(result + ', total ' + str(self.total))
        else:
            print("导出失败")
        self.printed = self.printed + 1
        print('导出第', self.printed, '本')
        if self.printed < self.total:
            self.print_book()
        else:
            print('开始合并')
            merger = PdfFileMerger()
            for index in range(0, self.total):
                filepath = self.filename + '.' + str(index) + '.pdf'
                merger.append(filepath)
                print('合并第', index, '本')
            merger.write(self.filename)
            merger.close()
            print('合并完成，开始清除临时文件')
            # for index in range(0, self.total):
            #     filepath = self.filename + '.' + str(index) + '.pdf'
            #     os.remove(filepath)
            print('清除临时文件完成')
            QApplication.exit()