pdfobject.js

/*global ActiveXObject, window, console, define, module, jQuery */
//jshint unused:false, strict: false

/*
    PDFObject v2.1.1
    https://github.com/pipwerks/PDFObject
    Copyright (c) 2008-2018 Philip Hutchison
    MIT-style license: http:https://pipwerks.mit-license.org/
    UMD module pattern from https://github.com/umdjs/umd/blob/master/templates/returnExports.js
*/

(function (root, factory) {
    if (typeof define === 'function' && define.amd) {
        // AMD. Register as an anonymous module.
        define([], factory);
    } else if (typeof module === 'object' && module.exports) {
        // Node. Does not work with strict CommonJS, but
        // only CommonJS-like environments that support module.exports,
        // like Node.
        module.exports = factory();
    } else {
        // Browser globals (root is window)
        root.PDFObject = factory();
  }
}(this, function () {

    "use strict";
    //jshint unused:true

    //PDFObject is designed for client-side (browsers), not server-side (node)
    //Will choke on undefined navigator and window vars when run on server
    //Return boolean false and exit function when running server-side

    if(typeof window === "undefined" || typeof navigator === "undefined"){ return false; }

    var pdfobjectversion = "2.1.1",
        ua = window.navigator.userAgent,

        //declare booleans
        supportsPDFs,
        isIE,
        supportsPdfMimeType = (typeof navigator.mimeTypes['application/pdf'] !== "undefined"),
        supportsPdfActiveX,
        isModernBrowser = (function (){ return (typeof window.Promise !== "undefined"); })(),
        isFirefox = (function (){ return (ua.indexOf("irefox") !== -1); } )(),
        isFirefoxWithPDFJS = (function (){
            //Firefox started shipping PDF.js in Firefox 19.
            //If this is Firefox 19 or greater, assume PDF.js is available
            if(!isFirefox){ return false; }
            //parse userAgent string to get release version ("rv")
            //ex: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:57.0) Gecko/20100101 Firefox/57.0
            return (parseInt(ua.split("rv:")[1].split(".")[0], 10) > 18);
        })(),
        isIOS = (function (){ return (/iphone|ipad|ipod/i.test(ua.toLowerCase())); })(),

        //declare functions
        createAXO,
        buildFragmentString,
        log,
        embedError,
        embed,
        getTargetElement,
        generatePDFJSiframe,
        generateEmbedElement;


    /* ----------------------------------------------------
       Supporting functions
       ---------------------------------------------------- */

    createAXO = function (type){
        var ax;
        try {
            ax = new ActiveXObject(type);
        } catch (e) {
            ax = null; //ensure ax remains null
        }
        return ax;
    };

    //IE11 still uses ActiveX for Adobe Reader, but IE 11 doesn't expose
    //window.ActiveXObject the same way previous versions of IE did
    //window.ActiveXObject will evaluate to false in IE 11, but "ActiveXObject" in window evaluates to true
    //so check the first one for older IE, and the second for IE11
    //FWIW, MS Edge (replacing IE11) does not support ActiveX at all, both will evaluate false
    //Constructed as a method (not a prop) to avoid unneccesarry overhead -- will only be evaluated if needed
    isIE = function (){ return !!(window.ActiveXObject || "ActiveXObject" in window); };

    //If either ActiveX support for "AcroPDF.PDF" or "PDF.PdfCtrl" are found, return true
    //Constructed as a method (not a prop) to avoid unneccesarry overhead -- will only be evaluated if needed
    supportsPdfActiveX = function (){ return !!(createAXO("AcroPDF.PDF") || createAXO("PDF.PdfCtrl")); };

    //Determines whether PDF support is available
    supportsPDFs = (
        //as of iOS 12, inline PDF rendering is still not supported in Safari or native webview
        //3rd-party browsers (eg Chrome, Firefox) use Apple's webview for rendering, and thus the same result as Safari
        //Therefore if iOS, we shall assume that PDF support is not available
        !isIOS && (
            //Modern versions of Firefox come bundled with PDFJS
            isFirefoxWithPDFJS || 
            //Browsers that still support the original MIME type check
            supportsPdfMimeType || (
                //Pity the poor souls still using IE
                isIE() && supportsPdfActiveX()
            )
        )
    );

    //Create a fragment identifier for using PDF Open parameters when embedding PDF
    buildFragmentString = function(pdfParams){

        var string = "",
            prop;

        if(pdfParams){

            for (prop in pdfParams) {
                if (pdfParams.hasOwnProperty(prop)) {
                    string += encodeURIComponent(prop) + "=" + encodeURIComponent(pdfParams[prop]) + "&";
                }
            }

            //The string will be empty if no PDF Params found
            if(string){

                string = "#" + string;

                //Remove last ampersand
                string = string.slice(0, string.length - 1);

            }

        }

        return string;

    };

    log = function (msg){
        if(typeof console !== "undefined" && console.log){
            console.log("[PDFObject] " + msg);
        }
    };

    embedError = function (msg){
        log(msg);
        return false;
    };

    getTargetElement = function (targetSelector){

        //Default to body for full-browser PDF
        var targetNode = document.body;

        //If a targetSelector is specified, check to see whether
        //it's passing a selector, jQuery object, or an HTML element

        if(typeof targetSelector === "string"){

            //Is CSS selector
            targetNode = document.querySelector(targetSelector);

        } else if (typeof jQuery !== "undefined" && targetSelector instanceof jQuery && targetSelector.length) {

            //Is jQuery element. Extract HTML node
            targetNode = targetSelector.get(0);

        } else if (typeof targetSelector.nodeType !== "undefined" && targetSelector.nodeType === 1){

            //Is HTML element
            targetNode = targetSelector;

        }

        return targetNode;

    };

    generatePDFJSiframe = function (targetNode, url, pdfOpenFragment, PDFJS_URL, id){

        var fullURL = PDFJS_URL + "?file=" + encodeURIComponent(url) + pdfOpenFragment;
        var scrollfix = (isIOS) ? "-webkit-overflow-scrolling: touch; overflow-y: scroll; " : "overflow: hidden; ";
        var iframe = "<div style='" + scrollfix + "position: absolute; top: 0; right: 0; bottom: 0; left: 0;'><iframe  " + id + " src='" + fullURL + "' style='border: none; width: 100%; height: 100%;' frameborder='0'></iframe></div>";
        targetNode.className += " pdfobject-container";
        targetNode.style.position = "relative";
        targetNode.style.overflow = "auto";
        targetNode.innerHTML = iframe;
        return targetNode.getElementsByTagName("iframe")[0];

    };

    generateEmbedElement = function (targetNode, targetSelector, url, pdfOpenFragment, width, height, id){

        var style = "";

        if(targetSelector && targetSelector !== document.body){
            style = "width: " + width + "; height: " + height + ";";
        } else {
            style = "position: absolute; top: 0; right: 0; bottom: 0; left: 0; width: 100%; height: 100%;";
        }

        targetNode.className += " pdfobject-container";
        targetNode.innerHTML = "<embed " + id + " class='pdfobject' src='" + url + pdfOpenFragment + "' type='application/pdf' style='overflow: auto; " + style + "'/>";

        return targetNode.getElementsByTagName("embed")[0];

    };

    embed = function(url, targetSelector, options){

        //Ensure URL is available. If not, exit now.
        if(typeof url !== "string"){ return embedError("URL is not valid"); }

        //If targetSelector is not defined, convert to boolean
        targetSelector = (typeof targetSelector !== "undefined") ? targetSelector : false;

        //Ensure options object is not undefined -- enables easier error checking below
        options = (typeof options !== "undefined") ? options : {};

        //Get passed options, or set reasonable defaults
        var id = (options.id && typeof options.id === "string") ? "id='" + options.id + "'" : "",
            page = (options.page) ? options.page : false,
            pdfOpenParams = (options.pdfOpenParams) ? options.pdfOpenParams : {},
            fallbackLink = (typeof options.fallbackLink !== "undefined") ? options.fallbackLink : true,
            width = (options.width) ? options.width : "100%",
            height = (options.height) ? options.height : "100%",
            assumptionMode = (typeof options.assumptionMode === "boolean") ? options.assumptionMode : true,
            forcePDFJS = (typeof options.forcePDFJS === "boolean") ? options.forcePDFJS : false,
            PDFJS_URL = (options.PDFJS_URL) ? options.PDFJS_URL : false,
            targetNode = getTargetElement(targetSelector),
            fallbackHTML = "",
            pdfOpenFragment = "",
            fallbackHTML_default = "<p>This browser does not support inline PDFs. Please download the PDF to view it: <a href='[url]'>Download PDF</a></p>";

        //If target element is specified but is not valid, exit without doing anything
        if(!targetNode){ return embedError("Target element cannot be determined"); }


        //page option overrides pdfOpenParams, if found
        if(page){
            pdfOpenParams.page = page;
        }

        //Stringify optional Adobe params for opening document (as fragment identifier)
        pdfOpenFragment = buildFragmentString(pdfOpenParams);

        //Do the dance

        //If the forcePDFJS option is invoked, skip everything else and embed as directed
        if(forcePDFJS && PDFJS_URL){

            return generatePDFJSiframe(targetNode, url, pdfOpenFragment, PDFJS_URL, id);

        //If traditional support is provided, or if this is a modern browser and not iOS (see comment for supportsPDFs declaration)
        } else if(supportsPDFs || (assumptionMode && isModernBrowser && !isIOS)){

            return generateEmbedElement(targetNode, targetSelector, url, pdfOpenFragment, width, height, id);

        //If everything else has failed and a PDFJS fallback is provided, try to use it
        } else if(PDFJS_URL){

            return generatePDFJSiframe(targetNode, url, pdfOpenFragment, PDFJS_URL, id);

        } else {

            //Display the fallback link if available
            if(fallbackLink){

                fallbackHTML = (typeof fallbackLink === "string") ? fallbackLink : fallbackHTML_default;
                targetNode.innerHTML = fallbackHTML.replace(/\[url\]/g, url);

            }

            return embedError("This browser does not support embedded PDFs");

        }

    };

    return {
        embed: function (a,b,c){ return embed(a,b,c); },
        pdfobjectversion: (function () { return pdfobjectversion; })(),
        supportsPDFs: (function (){ return supportsPDFs; })()
    };

}));