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webpack tabable 为什么选择实时 generateCode?
source link: https://www.v2ex.com/t/821298
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tabable 中的各种 hook 最终被 call 的时候，会通过 new Function(args, codeContent) 的形式生成一个函数
我好奇的是为什么它一定要用这种方式？例如：
case "sync":
if (!rethrowIfPossible) {
code += `var _hasError${tapIndex} = false;\n`;
code += "try {\n";
}
if (onResult) {
code += `var _result${tapIndex} = _fn${tapIndex}(${this.args({
before: tap.context ? "_context" : undefined
})});\n`;
} else {
code += `_fn${tapIndex}(${this.args({
before: tap.context ? "_context" : undefined
})});\n`;
}
if (!rethrowIfPossible) {
code += "} catch(_err) {\n";
code += `_hasError${tapIndex} = true;\n`;
code += onError("_err");
code += "}\n";
code += `if(!_hasError${tapIndex}) {\n`;
}
if (onResult) {
code += onResult(`_result${tapIndex}`);
}
if (onDone) {
code += onDone();
}
if (!rethrowIfPossible) {
code += "}\n";
}
break;
可以看见是通过字符串生成 code 内容。
那为什么不直接将 callTap 的方法写死呢？
function call(...args) {
for (let tap of tapArr) {
tap.fn.apply(null, args);
}
}
这样不行吗？两者有什么区别？ tabable 选择上面那种事为了解决什么问题呢？有大佬提个醒吗？
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