te')); return $arr; } /* 遍历用户所有主题 * @param $uid 用户ID * @param int $page 页数 * @param int $pagesize 每页记录条数 * @param bool $desc 排序方式 TRUE降序 FALSE升序 * @param string $key 返回的数组用那一列的值作为 key * @param array $col 查询哪些列 */ function thread_tid_find_by_uid($uid, $page = 1, $pagesize = 1000, $desc = TRUE, $key = 'tid', $col = array()) { if (empty($uid)) return array(); $orderby = TRUE == $desc ? -1 : 1; $arr = thread_tid__find($cond = array('uid' => $uid), array('tid' => $orderby), $page, $pagesize, $key, $col); return $arr; } // 遍历栏目下tid 支持数组 $fid = array(1,2,3) function thread_tid_find_by_fid($fid, $page = 1, $pagesize = 1000, $desc = TRUE) { if (empty($fid)) return array(); $orderby = TRUE == $desc ? -1 : 1; $arr = thread_tid__find($cond = array('fid' => $fid), array('tid' => $orderby), $page, $pagesize, 'tid', array('tid', 'verify_date')); return $arr; } function thread_tid_delete($tid) { if (empty($tid)) return FALSE; $r = thread_tid__delete(array('tid' => $tid)); return $r; } function thread_tid_count() { $n = thread_tid__count(); return $n; } // 统计用户主题数 大数量下严谨使用非主键统计 function thread_uid_count($uid) { $n = thread_tid__count(array('uid' => $uid)); return $n; } // 统计栏目主题数 大数量下严谨使用非主键统计 function thread_fid_count($fid) { $n = thread_tid__count(array('fid' => $fid)); return $n; } ?>Read data from BLOB URL in Javascript - Stack Overflow

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    Read data from BLOB URL in Javascript - Stack Overflow

    programmeradmin4浏览0评论

    I have a BLOB URL, and I want to recreate it as a second BLOB URL, so that it is downloaded by default.

    var blob1 = new Blob(["Hello world!"], { type: "text/plain" });
url1 = window.URL.createObjectURL(blob1);

blob2=new Blob([url1], {type: 'application/octet-stream'});
url2 = window.URL.createObjectURL(blob2);

var a = document.createElement("a");
document.body.appendChild(a);
a.style = "display: none";
a.href = url2;
a.click();
window.URL.revokeObjectURL(url);

    I have a BLOB URL, and I want to recreate it as a second BLOB URL, so that it is downloaded by default.

    var blob1 = new Blob(["Hello world!"], { type: "text/plain" });
url1 = window.URL.createObjectURL(blob1);

blob2=new Blob([url1], {type: 'application/octet-stream'});
url2 = window.URL.createObjectURL(blob2);

var a = document.createElement("a");
document.body.appendChild(a);
a.style = "display: none";
a.href = url2;
a.click();
window.URL.revokeObjectURL(url);

    See in JSFiddle:

    https://jsfiddle/7spry3jn/

    But this only creates a text file containint the first URL. How can I Read data from the first BLOB URL in Javascript and feed it to create the second BLOB?

    • javascript
    • url
    • download
    • blob
    Share Improve this question edited Feb 27, 2016 at 13:30 Ho1 asked Feb 27, 2016 at 13:28 Ho1Ho1 1,2891 gold badge13 silver badges30 bronze badges 2
    • Why you want to create a 2nd blob? – Joel R Michaliszen Commented Feb 27, 2016 at 13:30
    • @JoelRamosMichaliszen The first one doesn't force download. So I have to create a second one with such feature. – Ho1 Commented Feb 27, 2016 at 13:30
    Add a ment  | 

    1 Answer 1

    Reset to default 10

    You can use the download attr in anchor element, that force the download and you dont need to reate another blob.

    But you need to pay attentio about browser support, see here all the browsers that accept the downloadattr: Can I Use

    var blob1 = new Blob(["Hello world!"], { type: "text/plain" });
url = window.URL.createObjectURL(blob1);

var a = document.createElement("a");
document.body.appendChild(a);
a.style = "display: none";
a.href = url;
a.setAttribute("download","Any name");
a.click();
window.URL.revokeObjectURL(url);

    And to read the content from a Blob you can use FileReader like this:

    var myBlob = new Blob(["Hello"], {type : "text/plain"});
var myReader = new FileReader();
//handler executed once reading(blob content referenced to a variable) from blob is finished. 
myReader.addEventListener("loadend", function(e){
    document.getElementById("text").innerHTML = e.srcElement.result;//prints a string
});
//start the reading process.
myReader.readAsText(myBlob);
    <p id="text"></p>

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