String.prototype.endsWith = function(pattern) {
    var d = this.length - pattern.length;
    return d >= 0 && this.lastIndexOf(pattern) === d;
};
$(document).ready(function() {
   $('a').each(function(i,e) {
		var href = $(e).attr('href');
		if(href.endsWith('pdf') || href.endsWith('PDF'))
			$(e).attr('href', 'javascript: renderPDF("' + href + '")');
   });
	$('#pdfModal').on('hidden.bs.modal', function (e) {
		pdfDoc.destroy();
	});

});

function renderPDF(pdf_url) {
    var url = pdf_url;

    // The workerSrc property shall be specified.

    pdfDoc = null;
       var pageNum = 1,
        pageRendering = false,
        pageNumPending = null,
        scale = 1.8,
        canvas = document.getElementById('pdfcanvas'),
        ctx = canvas.getContext('2d');
	ctx.clearRect(0, 0, canvas.width, canvas.height);

    /**
     * Get page info from document, resize canvas accordingly, and render page.
     * @param num Page number.
     */
    function renderPage(num) {
      pageRendering = true;
      // Using promise to fetch the page
      pdfDoc.getPage(num).then(function(page) {
        var viewport = page.getViewport(scale);
        canvas.height = viewport.height;
        canvas.width = viewport.width;

        // Render PDF page into canvas context
        var renderContext = {
          canvasContext: ctx,
          viewport: viewport
        };
        var renderTask = page.render(renderContext);

        // Wait for rendering to finish
        renderTask.promise.then(function() {
          pageRendering = false;
          if (pageNumPending !== null) {
            // New page rendering is pending
            renderPage(pageNumPending);
            pageNumPending = null;
          }
        });
      });

      // Update page counters
      document.getElementById('page_num').textContent = pageNum;
    }

    /**
     * If another page rendering in progress, waits until the rendering is
     * finised. Otherwise, executes rendering immediately.
     */
    function queueRenderPage(num) {
      if (pageRendering) {
        pageNumPending = num;
      } else {
        renderPage(num);
      }
    }

    /**
     * Displays previous page.
     */
    function onPrevPage() {
      if (pageNum <= 1) {
        return;
      }
      pageNum--;
      queueRenderPage(pageNum);
    }
    document.getElementById('prev').addEventListener('click', onPrevPage);

    /**
     * Displays next page.
     */
    function onNextPage() {
      if (pageNum >= pdfDoc.numPages) {
        return;
      }
      pageNum++;
      queueRenderPage(pageNum);
    }
    document.getElementById('next').addEventListener('click', onNextPage);

    /**
     * Asynchronously downloads PDF.
     */
    PDFJS.getDocument(url).then(function(pdfDoc_) {
      pdfDoc = pdfDoc_;
      document.getElementById('page_count').textContent = pdfDoc.numPages;

      // Initial/first page rendering
      renderPage(pageNum);
    });
	$('#pdfdownload').attr('href', pdf_url);
	$('#pdfModal').modal('show');	
                        
}