How to display whole PDF (not only one page) with PDF.JS?

PDFJS has a member variable numPages, so you’d just iterate through them. BUT it’s important to remember that getting a page in pdf.js is asynchronous, so the order wouldn’t be guaranteed. So you’d need to chain them. You could do something along these lines:

var currPage = 1; //Pages are 1-based not 0-based
var numPages = 0;
var thePDF = null;

//This is where you start
PDFJS.getDocument(url).then(function(pdf) {

        //Set PDFJS global object (so we can easily access in our page functions
        thePDF = pdf;

        //How many pages it has
        numPages = pdf.numPages;

        //Start with first page
        pdf.getPage( 1 ).then( handlePages );
});



function handlePages(page)
{
    //This gives us the page's dimensions at full scale
    var viewport = page.getViewport( 1 );

    //We'll create a canvas for each page to draw it on
    var canvas = document.createElement( "canvas" );
    canvas.style.display = "block";
    var context = canvas.getContext('2d');
    canvas.height = viewport.height;
    canvas.width = viewport.width;

    //Draw it on the canvas
    page.render({canvasContext: context, viewport: viewport});

    //Add it to the web page
    document.body.appendChild( canvas );

    //Move to next page
    currPage++;
    if ( thePDF !== null && currPage <= numPages )
    {
        thePDF.getPage( currPage ).then( handlePages );
    }
}