Homelab, Linux, JS & ABAP (~˘▾˘)~
 

[PDF.js] Get PDF Viewer when it’s available in DOM and fully initialized

https://github.com/mozilla/pdf.js/wiki/Third-party-viewer-usage

<iframe id="pdf-js-viewer" src="/pdf/web/viewer.html?file=" title="webviewer" frameborder="0" width="100%" height="700" allowfullscreen="" webkitallowfullscreen=""/>
            displayPdf: async function (id) { 
                const pdfArrayBuffer= await getPdf(id)
                const pdfViewerIFrame = await getPdfViewer()
                await pdfViewerIFrame.contentWindow.PDFViewerApplication.initializedPromise
                await pdfViewerIFrame.contentWindow.PDFViewerApplication.open(pdfArrayBuffer)
            },

            getPdfViewer: function (id = 'pdf-js-viewer') {
                return new Promise((resolve, reject) => {
                    let pdfViewerIFrame = document.getElementById(id)
                    //if already loaded in DOM, return it
                    if (pdfViewerIFrame?.contentWindow?.PDFViewerApplication) {
                        resolve(pdfViewerIFrame)
                    } else {
                        //if not loaded yet, set up eventListener
                        document.addEventListener("webviewerloaded", async () => {
                            pdfViewerIFrame = document.getElementById(id)
                            resolve(pdfViewerIFrame)
                        })
                    }
                })
            }

This logic helped me to get the PDFViewerApplication in every situation correctly, for example when reloading the page with F5 or when having the PDF viewer already loaded and just wanting to open another PDF file.

Leave a Reply

Your email address will not be published. Required fields are marked *