Adding Footer to pdf using jsPDF

问题:

I am generating pdf from jsPDF api , I want to add footer to each page with page number .

How to achieve this . It is having option of adding footer from fromHTML plugin , but I am writing without HTML.

var doc = new jsPDF("portrait","px","a4");

回答1:

You have to implement it yourself. You can do something like this:

var doc = new jsPDF();
doc.page=1; // use this as a counter.

function footer(){ 
    doc.text(150,285, 'page ' + doc.page); //print number bottom right
    doc.page ++;
};

// and call footer() after each doc.addPage()

回答2:

If you need something like "current page / totalPage" displaying for each page. Using "Total page number" plugin available in jspdf v1.0+

How to use:

        var doc = new jsPDF();
        doc.page=1; // use this as a counter.
        var totalPagesExp = "{total_pages_count_string}";


        function footer(){ 
          var str = "Page " + doc.page;           
          if (typeof doc.putTotalPages === 'function') {
            str = str + "/" + totalPagesExp;
          }
          doc.text(150,285, str); //print number bottom right
        }

        // call footer() after each doc.addPage()

        // and before doc.save() do not forget put
        if (typeof doc.putTotalPages === 'function') {
            doc.putTotalPages(totalPagesExp);
        }

It should work. Hope this helps.

回答3:

After digging into the code, I think the feature you ask is not implemented. But there is a function to generate a footer from html and you can use this code to fullfill your need. But beware some part of the code is marked as "bad hack".

From plugins/from_html.js

checkForFooter = function (elem, renderer, elementHandlers) {
    //check if we can found a <footer> element
    var footer = elem.getElementsByTagName("footer");
    if (footer.length > 0) {

        footer = footer[0];

        //bad hack to get height of footer
        //creat dummy out and check new y after fake rendering
        var oldOut = renderer.pdf.internal.write;
        var oldY = renderer.y;
        renderer.pdf.internal.write = function () {};
        DrillForContent(footer, renderer, elementHandlers);
        var footerHeight = Math.ceil(renderer.y - oldY) + 5;
        renderer.y = oldY;
        renderer.pdf.internal.write = oldOut;

        //add 20% to prevent overlapping
        renderer.pdf.margins_doc.bottom += footerHeight;

        //Create function render header on every page
        var renderFooter = function (pageInfo) {
            var pageNumber = pageInfo !== undefined ? pageInfo.pageNumber : 1;
            //set current y position to old margin
            var oldPosition = renderer.y;
            //render all child nodes of the header element
            renderer.y = renderer.pdf.internal.pageSize.height - renderer.pdf.margins_doc.bottom;
            renderer.pdf.margins_doc.bottom -= footerHeight;

            //check if we have to add page numbers
            var spans = footer.getElementsByTagName('span');
            for (var i = 0; i < spans.length; ++i) {
                //if we find some span element with class pageCounter, set the page
                if ((" " + spans[i].className + " ").replace(/[\n\t]/g, " ").indexOf(" pageCounter ") > -1) {
                    spans[i].innerHTML = pageNumber;
                }
                //if we find some span element with class totalPages, set a variable which is replaced after rendering of all pages
                if ((" " + spans[i].className + " ").replace(/[\n\t]/g, " ").indexOf(" totalPages ") > -1) {
                    spans[i].innerHTML = '###jsPDFVarTotalPages###';
                }
            }

            //render footer content
            DrillForContent(footer, renderer, elementHandlers);
            //set bottom margin to previous height including the footer height
            renderer.pdf.margins_doc.bottom += footerHeight;
            //important for other plugins (e.g. table) to start rendering at correct position after header
            renderer.y = oldPosition;
        };

        //check if footer contains totalPages which shoudl be replace at the disoposal of the document
        var spans = footer.getElementsByTagName('span');
        for (var i = 0; i < spans.length; ++i) {
            if ((" " + spans[i].className + " ").replace(/[\n\t]/g, " ").indexOf(" totalPages ") > -1) {
                renderer.pdf.internal.events.subscribe('htmlRenderingFinished', renderer.pdf.putTotalPages.bind(renderer.pdf, '###jsPDFVarTotalPages###'), true);
            }
        }

        //register event to render footer on every new page
        renderer.pdf.internal.events.subscribe('addPage', renderFooter, false);
        //render footer on first page
        renderFooter();

        //prevent footer rendering
        SkipNode['FOOTER'] = 1;
    }
};

回答4:

I know this post is old but I'm going to offer another solution. First define your total amount of pages. There's multiple ways to determine this so I won't go into that.

        var doc = new jsPDF('p', 'pt', 'letter');
        doc.page = 1; // use this as a counter.
        var totalPages = 10; // define total amount of pages
        // HEADER
        doc.setFontSize(20);//optional
        doc.setTextColor(40);//optional
        doc.setFontStyle('normal');//optional
        doc.text("Report", 50, 22);// set your margins
        // FOOTER
        var str = "Page " + doc.page  + " of " +  totalPages;
        doc.setFontSize(10);// optional
        doc.text(str, 50, doc.internal.pageSize.height - 10);//key is the interal pageSize function


        // Add Page content
        .....


        //Add new page and increase page count
        doc.addPage();
        doc.page ++;
        //Begin process all over again.

This works well in a loop as you can set your page count by taking your array.length + 1 (as it's zero based).

回答5:

Run this function before you run doc.save()

function addFooters() {
    const pageCount = doc.internal.getNumberOfPages();
    for(var i = 0; i < pageCount; i++) {
        doc.text(String(i),196,285);
    }
}