Come scaricare una GIF da un determinato URL utilizzando Javascript

Aug 17 2020

Sto cercando di scaricare una GIF da Giphy (devo solo scaricarla, non ho bisogno di visualizzarla sul browser).

Ho provato a utilizzare la soluzione in questa domanda questa domanda tuttavia scarica un'immagine statica:

function download_img(e, link){
    var image = new Image();
    image.crossOrigin = "anonymous";
    image.src = link;
    image.onload = function () {
        var canvas = document.createElement('canvas');
        canvas.width = this.naturalWidth; // or 'width' if you want a special/scaled size
        canvas.height = this.naturalHeight; // or 'height' if you want a special/scaled size
        canvas.getContext('2d').drawImage(this, 0, 0);
        var blob;
        // ... get as Data URI
        if (image.src.indexOf(".jpg") > -1) {
            blob = canvas.toDataURL("image/jpeg");
        } else if (image.src.indexOf(".png") > -1) {
            blob = canvas.toDataURL("image/png");
        } else if (image.src.indexOf(".gif") > -1) {
            blob = canvas.toDataURL("image/gif");
        } else {
            blob = canvas.toDataURL("image/png");
        }
        tempbtn = document.createElement('a');
        tempbtn.href = blob;
        tempbtn.download = 'giphy.gif'; // or define your own name. 
        tempbtn.click();
        tempbtn.remove(); 
    };
}
<a href="#" onclick="download_img(this,'https://media2.giphy.com/media/DvyLQztQwmyAM/giphy.gif?cid=e9ff928175irq2ybzjyiuicjuxk21vv4jyyn0ut5o0d7co50&rid=giphy.gif')"  > Descargar gif </a>

Mi chiedo anche perché sia ​​necessario creare a new Image();e creare acanvas tag

Risposte

jmp Aug 17 2020 at 01:59

Questo funziona per me, ho preso parte del codice da quihttps://randomtutes.com/2019/08/02/download-blob-as-file-in-javascript/

(async () => {
  //create new a element
  let a = document.createElement('a');
  // get image as blob
  let response = await fetch('https://media2.giphy.com/media/DvyLQztQwmyAM/giphy.gif?cid=e9ff928175irq2ybzjyiuicjuxk21vv4jyyn0ut5o0d7co50&rid=giphy.gif');
  let file = await response.blob();
  // use download attribute https://developer.mozilla.org/en-US/docs/Web/HTML/Element/a#Attributes
  a.download = 'myGif';
  a.href = window.URL.createObjectURL(file);
  //store download url in javascript https://developer.mozilla.org/en-US/docs/Learn/HTML/Howto/Use_data_attributes#JavaScript_access
  a.dataset.downloadurl = ['application/octet-stream', a.download, a.href].join(':');
  //click on element to start download
  a.click();
})();
SulavSapkota Aug 17 2020 at 01:10

Sono riuscito a farlo funzionare anche in Chrome e Firefox aggiungendo un collegamento al documento.

var link = document.createElement('a');
link.href = 'images.jpg';
link.download = 'Download.jpg';
document.body.appendChild(link);
link.click();
document.body.removeChild(link);