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Internet Explorer doesn't implement ArrayBuffer.prototype.slice. Amazingly, they don't plan on implementing it any time soon. As such, are there any shims out there for this function? If not then this shall be the canonical answer on the internet as soon as I or someone else implements one.

Internet Explorer doesn't implement ArrayBuffer.prototype.slice. Amazingly, they don't plan on implementing it any time soon. As such, are there any shims out there for this function? If not then this shall be the canonical answer on the internet as soon as I or someone else implements one.

• javascript
• internet-explorer
• patibility
• shim
• arraybuffer

Share Improve this question Follow asked Jan 29, 2014 at 18:54 ClaudiuClaudiu 230k173173 gold badges504504 silver badges699699 bronze badges 2

• What's the most straightforward way to copy an ArrayBuffer object? does offer a shim – Bergi Commented Jan 29, 2014 at 19:08
• @Bergi: ah thanks. that's an awful shim though, uses a for loop instead of set - perhaps worth it to put an answer there instead – Claudiu Commented Jan 29, 2014 at 19:14

Add a ment  | 

2 Answers 2

Sorted by: Reset to default 4

This seems to do the trick. Open to suggestions.

if (!ArrayBuffer.prototype.slice) {
    //Returns a new ArrayBuffer whose contents are a copy of this ArrayBuffer's
    //bytes from `begin`, inclusive, up to `end`, exclusive
    ArrayBuffer.prototype.slice = function (begin, end) {
        //If `begin` is unspecified, Chrome assumes 0, so we do the same
        if (begin === void 0) {
            begin = 0;
        }

        //If `end` is unspecified, the new ArrayBuffer contains all
        //bytes from `begin` to the end of this ArrayBuffer.
        if (end === void 0) {
            end = this.byteLength;
        }

        //Chrome converts the values to integers via flooring
        begin = Math.floor(begin);
        end = Math.floor(end);

        //If either `begin` or `end` is negative, it refers to an
        //index from the end of the array, as opposed to from the beginning.
        if (begin < 0) {
            begin += this.byteLength;
        }
        if (end < 0) {
            end += this.byteLength;
        }

        //The range specified by the `begin` and `end` values is clamped to the 
        //valid index range for the current array.
        begin = Math.min(Math.max(0, begin), this.byteLength);
        end = Math.min(Math.max(0, end), this.byteLength);

        //If the puted length of the new ArrayBuffer would be negative, it 
        //is clamped to zero.
        if (end - begin <= 0) {
            return new ArrayBuffer(0);
        }

        var result = new ArrayBuffer(end - begin);
        var resultBytes = new Uint8Array(result);
        var sourceBytes = new Uint8Array(this, begin, end - begin);

        resultBytes.set(sourceBytes);

        return result;
    };
}

Slightly adapted as per ments version of index.js from ttaubert's Arraybuffer-slice github repo

if (!ArrayBuffer.prototype.slice) {
  ArrayBuffer.prototype.slice = function (begin, end) {
    var len = this.byteLength;
    begin = (begin|0) || 0;
    end = end === (void 0) ? len : (end|0);

    // Handle negative values.
    if (begin < 0) begin = Math.max(begin + len, 0);
    if (end < 0) end = Math.max(end + len, 0);

    if (len === 0 || begin >= len || begin >= end) {
      return new ArrayBuffer(0);
    }

    var length = Math.min(len - begin, end - begin);
    var target = new ArrayBuffer(length);
    var targetArray = new Uint8Array(target);
    targetArray.set(new Uint8Array(this, begin, length));
    return target;
  };
}

Internet Explorer doesn't implement ArrayBuffer.prototype.slice. Amazingly, they don't plan on implementing it any time soon. As such, are there any shims out there for this function? If not then this shall be the canonical answer on the internet as soon as I or someone else implements one.

Internet Explorer doesn't implement ArrayBuffer.prototype.slice. Amazingly, they don't plan on implementing it any time soon. As such, are there any shims out there for this function? If not then this shall be the canonical answer on the internet as soon as I or someone else implements one.

• javascript
• internet-explorer
• patibility
• shim
• arraybuffer

Share Improve this question Follow asked Jan 29, 2014 at 18:54 ClaudiuClaudiu 230k173173 gold badges504504 silver badges699699 bronze badges 2

• What's the most straightforward way to copy an ArrayBuffer object? does offer a shim – Bergi Commented Jan 29, 2014 at 19:08
• @Bergi: ah thanks. that's an awful shim though, uses a for loop instead of set - perhaps worth it to put an answer there instead – Claudiu Commented Jan 29, 2014 at 19:14

Add a ment  | 

2 Answers 2

Sorted by: Reset to default 4

This seems to do the trick. Open to suggestions.

if (!ArrayBuffer.prototype.slice) {
    //Returns a new ArrayBuffer whose contents are a copy of this ArrayBuffer's
    //bytes from `begin`, inclusive, up to `end`, exclusive
    ArrayBuffer.prototype.slice = function (begin, end) {
        //If `begin` is unspecified, Chrome assumes 0, so we do the same
        if (begin === void 0) {
            begin = 0;
        }

        //If `end` is unspecified, the new ArrayBuffer contains all
        //bytes from `begin` to the end of this ArrayBuffer.
        if (end === void 0) {
            end = this.byteLength;
        }

        //Chrome converts the values to integers via flooring
        begin = Math.floor(begin);
        end = Math.floor(end);

        //If either `begin` or `end` is negative, it refers to an
        //index from the end of the array, as opposed to from the beginning.
        if (begin < 0) {
            begin += this.byteLength;
        }
        if (end < 0) {
            end += this.byteLength;
        }

        //The range specified by the `begin` and `end` values is clamped to the 
        //valid index range for the current array.
        begin = Math.min(Math.max(0, begin), this.byteLength);
        end = Math.min(Math.max(0, end), this.byteLength);

        //If the puted length of the new ArrayBuffer would be negative, it 
        //is clamped to zero.
        if (end - begin <= 0) {
            return new ArrayBuffer(0);
        }

        var result = new ArrayBuffer(end - begin);
        var resultBytes = new Uint8Array(result);
        var sourceBytes = new Uint8Array(this, begin, end - begin);

        resultBytes.set(sourceBytes);

        return result;
    };
}

Slightly adapted as per ments version of index.js from ttaubert's Arraybuffer-slice github repo

if (!ArrayBuffer.prototype.slice) {
  ArrayBuffer.prototype.slice = function (begin, end) {
    var len = this.byteLength;
    begin = (begin|0) || 0;
    end = end === (void 0) ? len : (end|0);

    // Handle negative values.
    if (begin < 0) begin = Math.max(begin + len, 0);
    if (end < 0) end = Math.max(end + len, 0);

    if (len === 0 || begin >= len || begin >= end) {
      return new ArrayBuffer(0);
    }

    var length = Math.min(len - begin, end - begin);
    var target = new ArrayBuffer(length);
    var targetArray = new Uint8Array(target);
    targetArray.set(new Uint8Array(this, begin, length));
    return target;
  };
}

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