Convert HTML to PDF in Angular 6

2020-02-27 03:57发布

问题:

I have a component (Angular 6) which is an aggregation of several components. This produces a long HTML (I am using Bootstrap 4). Now I want to convert this HTML to PDF. I have searched far and wide and found many solutions that work on jsPDF. The requirement is to produce a crisp layout as it appears in the HTML (so that users can select, copy, etc). But the solutions I found either try to add lines of text manually, which is impossible in my scenario; or they convert (rasterize?) the HTML to image format. Also, I want to preserve the formatting and fonts and styling of my HTML.

So far I have tried: this and this.

回答1:

Best possible solution I could come up with till now.

You would have to install the below packages from npm

html2canvas

jspdf

import * as jsPDF from 'jspdf';
import html2canvas from 'html2canvas';

htmltoPDF()
{
    // parentdiv is the html element which has to be converted to PDF
    html2canvas(document.querySelector("#parentdiv")).then(canvas => {

      var pdf = new jsPDF('p', 'pt', [canvas.width, canvas.height]);

      var imgData  = canvas.toDataURL("image/jpeg", 1.0);
      pdf.addImage(imgData,0,0,canvas.width, canvas.height);
      pdf.save('converteddoc.pdf');

  });

}

UPDATE:

Came up with another solution. I wasn't able to break it down into A4 size pages, but I was able to make a single pdf file.

Packages:

dom-to-image

jspdf

import domtoimage from 'dom-to-image';
import * as jsPDF from 'jspdf';



            downloadPDF()
            {

              var node = document.getElementById('parentdiv');

              var img;
              var filename;
              var newImage;


              domtoimage.toPng(node, { bgcolor: '#fff' })

                .then(function(dataUrl) {

                  img = new Image();
                  img.src = dataUrl;
                  newImage = img.src;

                  img.onload = function(){

                  var pdfWidth = img.width;
                  var pdfHeight = img.height;

                    // FileSaver.saveAs(dataUrl, 'my-pdfimage.png'); // Save as Image

                    var doc;

                    if(pdfWidth > pdfHeight)
                    {
                      doc = new jsPDF('l', 'px', [pdfWidth , pdfHeight]);
                    }
                    else
                    {
                      doc = new jsPDF('p', 'px', [pdfWidth , pdfHeight]);
                    }


                    var width = doc.internal.pageSize.getWidth();
                    var height = doc.internal.pageSize.getHeight();


                    doc.addImage(newImage, 'PNG',  10, 10, width, height);
                    filename = 'mypdf_' + '.pdf';
                    doc.save(filename);

                  };


                })
                .catch(function(error) {

                 // Error Handling

                });



            }


回答2:

With some effort, the best solution my team and I came up with for our own Angular HTML to PDF problems involved sending the raw HTML to our Java API and then utilizing wkhtmltopdf (https://github.com/wkhtmltopdf/wkhtmltopdf) with the Java wrapper (https://github.com/jhonnymertz/java-wkhtmltopdf-wrapper). Overcoming a few gotchas (like making sure the server has the correctly installed fonts; everything is properly encoded; figuring out page breaks and making them work), we were able to reproduce our page exactly and use our Angular HTML as the universal template (which changes based on different scenarios). It is not an easy road, but it is one that produces great results in an enterprise-level production environment once you get it figured out.

It should be noted that we also tried jspdf (and other libraries) and came to similar conclusions as yourself: they just didn't do what we needed them to do. Hopefully this helps.



回答3:

The following code was used and worked for my project

Step 1 : Run following commands to install npm packages

> npm install jspdf
> npm install html2canvas

Step 2: Import installed packages in app.components.ts. I haven't imported those packages in constructor()

> import * as jspdf from 'jspdf';
> import html2canvas from 'html2canvas';

Step 3: Give an id for the HTML div that has to be exported as PDF. Add a button that activates the function too.

<div id="MyDIv" style="margin-left: 45px;" class="main-container">

</div>
<div class="icon_image " title="Share As PDF" (click)="exportAsPDF('MyDIv');"><img src="assets/img/pdf.png"></div>

Step 4 : Write the code for generating PDF as follows

exportAsPDF()
  {
    let data = document.getElementById('MyDIv');  
    html2canvas(data).then(canvas => {
      const contentDataURL = canvas.toDataURL('image/png')  
      let pdf = new jspdf('l', 'cm', 'a4'); //Generates PDF in landscape mode
      // let pdf = new jspdf('p', 'cm', 'a4'); Generates PDF in portrait mode
      pdf.addImage(contentDataURL, 'PNG', 0, 0, 29.7, 21.0);  
      pdf.save('Filename.pdf');   
    }); 
  }


回答4:

Refer this you may get some ideas pdf-angular

npm-angular



回答5:

Try to use a backend service for this such as Thymeleaf or itextpdf with Spring Boot.



回答6:

Firstly install the following: 1) npm install jspdf 2) npm install html2canvas

Later import and use the following code

 public captureScreen() {
      const data = document.getElementById('invoice');
      html2canvas(data).then(canvas => {
      const imgWidth = 208;
      const pageHeight = 295;
      const imgHeight = canvas.height * imgWidth / canvas.width;
      const heightLeft = imgHeight;
      const contentDataURL = canvas.toDataURL('image/png');
      const pdf = new jspdf('p', 'mm', 'a4'); 
      const position = 0;
      pdf.addImage(contentDataURL, 'PNG', 0, position, imgWidth, imgHeight);
      pdf.save('invoice.pdf'); 
      });
      }