Is There Any Way To Center Text With JsPDF?

January 31, 2023 Post a Comment

I'm trying to create a simple pdf doc using javascript. I found jsPDF but I don't figure out how to center text. Is it possible?

Solution 1:

Yes it's possible. You could write a jsPDF plugin method to use.

One quick example is this:

    (function(API){
    API.myText = function(txt, options, x, y) {
        options = options ||{};
        /* Use the options align property to specify desired text alignment
         * Param x will be ignored if desired text alignment is 'center'.
         * Usage of options can easily extend the function to apply different text 
         * styles and sizes 
        */
        if( options.align == "center" ){
            // Get current font size
            var fontSize = this.internal.getFontSize();

            // Get page width
            var pageWidth = this.internal.pageSize.width;

            // Get the actual text's width
            /* You multiply the unit width of your string by your font size and divide
             * by the internal scale factor. The division is necessary
             * for the case where you use units other than 'pt' in the constructor
             * of jsPDF.
            */
            txtWidth = this.getStringUnitWidth(txt)*fontSize/this.internal.scaleFactor;

            // Calculate text's x coordinate
            x = ( pageWidth - txtWidth ) / 2;
        }

        // Draw text at x,y
        this.text(txt,x,y);
    }
})(jsPDF.API);

And you use it like this

var doc = new jsPDF('p','in');
doc.text("Left aligned text",0.5,0.5);
doc.myText("Centered text",{align: "center"},0,1);

Solution 2:

This works in the scratchpad on the jsPdf homepage:

var centeredText = function(text, y) {
    var textWidth = doc.getStringUnitWidth(text) * doc.internal.getFontSize() / doc.internal.scaleFactor;
    var textOffset = (doc.internal.pageSize.width - textWidth) / 2;
    doc.text(textOffset, y, text);
}

Solution 3:

I have found that the current version of jsPdf supports a parameter 'align' with the function signature like this:

API.text = function (text, x, y, flags, angle, align)

So the following should give you a center-aligned text:

doc.text('The text', doc.internal.pageSize.width, 50, null, null, 'center');

However, at the current point in time, an error is thrown in the library when strict mode is on because a 'var' is missing. There is an issue and pull request for it, but the fix hasn't made it in: https://github.com/MrRio/jsPDF/issues/575

Whoever is looking for this, one day, you might be able to use this to make it easier to center text.

Solution 4:

WootWoot, just in case you need more layout options, you could also take a look at my pdfmake library

It supports:

text alignments, lists, margins
styling (with style inheritance)
tables with auto/fixed/star sized columns, auto-repeated headers, col/row spans
page headers and footers
font embedding, and a couple of other options

It works on client-side (pure JS) or server-side (an npm module)

Take a look at the playground to see what's possible

Good luck

Solution 5:

I had the same problem and a lot of others while creating PDF-Files (e.g. auto-pagebreak, total-pageCount). So i started writing a little lib, which depends on jsPDF but gives you a lot of features in a way you know them (form HTML/CSS and jQuery). You can find it on GitHub. I hope it makes PDF-Creating easier... =)

JavaScript Lib