I have this piece of code and ran it through JSLint to make sure everything is according to best practices. It's basically a custom feature detection.
我有这段代码，并通过JSLint运行它，以确保一切都符合最佳实践。这基本上是一个自定义特征检测。
(function() {
var vendorArray = ['', '-webkit-'],
vendorIndex = vendorArray.length,
mergedProperty,
validProperty,
activePrefix,
detectorElement = document.createElement('detector'),
detectorStyle = detectorElement.style,
prefixRegex = new RegExp('%prfx%', 'g'),
camelRegex = new RegExp('\-([a-z])', 'g'),
propertyArray = [
['backgroundImage', 'background-image: %prfx%linear-gradient(rgba(0, 0, 0, 0), rgba(0, 0, 0, 1)), %prfx%linear-gradient(rgba(0, 0, 0, 0.5) 1%, rgba(0, 0, 0, 0.5) 99%)'],
['boxShadow', 'box-shadow: 1px 1px 1px 1px rgba(0, 0, 0, 0.5), inset 1px 1px 1px 1px rgba(0, 0, 0, 1)'],
['transition', '%prfx%transition: all 1s'],
['animation', '%prfx%animation: example 1s'],
['transform', '%prfx%transform: translate3d(1px, 1px, 1px)']
];
// property ist z.B. propertyArray[0] also das erste Property im Array; mit prefix kann man angeben ob das js Attribut ein Vendor-Prefix benötigt - 0 oder 1
function vendorCheck(property, prefix) {
// Zur Sicherheit löschen wir das gesamte style-Attribut zu Beginn
if (detectorElement.getAttribute('style')) {
detectorElement.removeAttribute('style');
}
while (vendorIndex--) {
// activePrefix cached den Index bzw. das Vendor-Prefix der Schleife z.b. -webkit-
activePrefix = vendorArray[vendorIndex];
// Das detector Element bekommt den Stil gesetzt >> property[1] = propertyArray[0][1] (propertyArray[0] wurde in die Funktion übergeben) >> im Stil wird der Platzhalter %prfx% mit dem jeweiligen aktiven Vendor-Prefix ersetzt
detectorStyle.cssText = property[1].replace(prefixRegex, activePrefix);
// Überprüfen ob das Attribut z.b. transition einen Vendor-Prefix erhalten soll, z.B. WebkitTransition
if (prefix === 1) {
// Aus dem String mergedProperty z.b. -webkit-transition wird -w und -t extrahiert und in Großbuchstaben zurückgegeben
mergedProperty = activePrefix + property[0];
validProperty = mergedProperty.replace(camelRegex, function(match, p1) {
return p1.toUpperCase();
});
}
// Wird prefix nicht übergeben, ist das Attribut gleich dem Attribut aus propertyArray
else {
validProperty = property[0];
}
// Wenn das detector Element der angewendeten Stil behalten hat, also das Attribut validProperty = property[0] = propertyArray[0][0] true ist, wird z.b. das Attribut WebkitTransition zurückgegeben und die Schleife beendet
if (detectorStyle[validProperty]) {
return validProperty;
}
}
};
document.getElementsByTagName('body')[0].innerHTML = detectorStyle[vendorCheck(propertyArray[4], 1)];
}());
However JSLint tells me that this part has some issues, since I'm declaring a function within a loop:
但是JSLint告诉我这部分有一些问题，因为我在循环中声明了一个函数:
validProperty = mergedProperty.replace(camelRegex, function(match, p1) {
return p1.toUpperCase();
});
Is there a way to have a named callback function that is outside the loop?
是否有一种方法可以将一个命名回调函数放在循环之外?
Find a Codepen here: http://codepen.io/lieferant/pen/kXJLjJ
在这里找到一个代码页:http://codepen.io/lieferant/pen/kXJLjJ
1 个解决方案
#1
2
Is there a way to have a named callback function that is outside the loop?
是否有一种方法可以将一个命名回调函数放在循环之外?
Yes, just declare it within your function, and call it:
是的，只要在函数中声明它，并调用它:
function vendorCheck(property, prefix) {
// ...
while (/*...*/) {
validProperty = mergedProperty.replace(capitalizeFirstCaptureGroup);
}
// ...
function capitalizeFirstCaptureGroup(match, p1) {
return p1.toUpperCase();
}
// ...
}
It can be at the top or bottom. It should be at the top level of the function, not within any control blocks. (As of ES2015, it's valid if it's inside a control block, but the rules are...complicated.)
它可以在顶部或底部。它应该位于函数的顶层，而不是在任何控制块中。(从ES2015年开始，如果它位于控制块内，是有效的，但规则……很复杂。)
Although actually, that one is general enough you might put it in a general utilities area and use it more broadly than just within vendorCheck.
尽管实际上，这一项是足够通用的，你可以把它放在一个通用的公用事业领域，并且比在vendorCheck中更广泛地使用它。
#1
2
Is there a way to have a named callback function that is outside the loop?
是否有一种方法可以将一个命名回调函数放在循环之外?
Yes, just declare it within your function, and call it:
是的，只要在函数中声明它，并调用它:
function vendorCheck(property, prefix) {
// ...
while (/*...*/) {
validProperty = mergedProperty.replace(capitalizeFirstCaptureGroup);
}
// ...
function capitalizeFirstCaptureGroup(match, p1) {
return p1.toUpperCase();
}
// ...
}
It can be at the top or bottom. It should be at the top level of the function, not within any control blocks. (As of ES2015, it's valid if it's inside a control block, but the rules are...complicated.)
它可以在顶部或底部。它应该位于函数的顶层，而不是在任何控制块中。(从ES2015年开始，如果它位于控制块内，是有效的，但规则……很复杂。)
Although actually, that one is general enough you might put it in a general utilities area and use it more broadly than just within vendorCheck.
尽管实际上，这一项是足够通用的，你可以把它放在一个通用的公用事业领域，并且比在vendorCheck中更广泛地使用它。