如何在“链接的”方法调用中使用条件语句？

Question

Is there a cleaner way of writing this code? It's only the .trim() statement that differs.

if (imageOptions.trim) {
    // Trim
    gm(imageBuffer, 'image.' + imageOptions.imageFormat)
        .gravity(imageOptions.gravity)
        .resize(imageOptions.imageWidth, imageOptions.imageHeight, '^')
        .crop(imageOptions.imageWidth, imageOptions.imageHeight)
        .trim()
        .toBuffer(imageOptions.imageFormat.toUpperCase(), callback);
}
else {
    // No trim
    gm(imageBuffer, 'image.' + imageOptions.imageFormat)
        .gravity(imageOptions.gravity)
        .resize(imageOptions.imageWidth, imageOptions.imageHeight, '^')
        .crop(imageOptions.imageWidth, imageOptions.imageHeight)
        .toBuffer(imageOptions.imageFormat.toUpperCase(), callback);
}

Bonus question: what's the proper terminology for these "linked" method calls?

Answer 1

You can assign the result of those method calls to a variable and then have a conditional, there's no need to write the entire chain unbroken:

var img = gm(...)
            .gravity(..)
            .resize(..)
            .crop(..);

if (imageOptions.trim) {
    img.trim();
}

img.toBuffer(..);

And these things are called chained method calls .