相关疑难解决方法(0)

我有一个JPS,其中包含一个用户可以放置图像的表单:

<div class="photo">
    <div>Photo (max 240x240 and 100 kb):</div>
    <input type="file" name="photo" id="photoInput" onchange="checkPhoto(this)"/>
</div>

我写过这个js:

function checkPhoto(target) {
    if(target.files[0].type.indexOf("image") == -1) {
        document.getElementById("photoLabel").innerHTML = "File not supported";
        return false;
    }
    if(target.files[0].size > 102400) {
        document.getElementById("photoLabel").innerHTML = "Image too big (max 100kb)";
        return false;
    }
    document.getElementById("photoLabel").innerHTML = "";
    return true;
}

它可以很好地检查文件类型和大小.现在我想检查图像的宽度和高度,但我不能这样做.
我试过target.files[0].width但我得到了undefined.通过其他方式我得到0.
有什么建议？

从 Rails 6 升级到 Rails 7 并在本地运行一些 ActiveStorage 方法时，我看到：

Could not open library 'vips.42': dlopen(vips.42, 0x0005): tried: 'vips.42' (no such file), '/usr/local/lib/vips.42' (no such file), '/usr/lib/vips.42' (no such file), '/Users/st/rails/myapp/vips.42' (no such file), '/usr/local/lib/vips.42' (no such file), '/usr/lib/vips.42' (no such file). (LoadError)
Could not open library 'libvips.42.dylib': dlopen(libvips.42.dylib, 0x0005): tried: 'libvips.42.dylib' (no such file), '/usr/local/lib/libvips.42.dylib' (no such file), '/usr/lib/libvips.42.dylib' (no such file), '/Users/st/rails/myapp/libvips.42.dylib' (no such file), '/usr/local/lib/libvips.42.dylib' (no such file), '/usr/lib/libvips.42.dylib' (no such file)

GitHub 上有很多类似的问题：（例如这里）。

我不确定是否需要安装 ruby​​-vips …