我在Plunker上发现了一些我不理解的代码。这是一个词云,云被添加到页面上,使用:
<tang-cloud words="words" on-click="test(word)" width="500" height="500"></tang-cloud>
这在某种程度上被Angular发现了。我不明白的是,我在其余的代码中找不到对"tang-cloud"的引用。各种"tangcloud"但没有连字符
我是Angular的新手,我偶然发现了另一个案例,似乎发生了这种情况,但我看到的所有教程案例都会使用"tangcloud"。如果我删除连字符,它就停止工作了,所以我一定是错过了一些简单的东西。
谢谢
这是指令。由于HTML是不区分大小写的,angular会将tangCloud
指令转换为tang-cloud
,以便HTML可以读取。
你可以在tangCloud.js中的tangCloud指令中找到相应的代码。
编辑:只是为了跟进,你看到那个说restrict: 'E'
的位了吗?这会告诉angular,你可以将该指令用作自定义元素。当你创建一个驼峰型指令时,比如tangCloud
, angular会自动将其转换为tang-cloud
。
.directive('tangCloud', ['$interpolate', '$compile', '$timeout', function ($interpolate, $compile, $timeout) {
var directive = {
restrict: 'E',
scope: {
width: '=',
height: '=',
words: '=',
onClick: '&',
spin: '='
},
template: function (tElement, tAttrs) {
var isClickable = angular.isDefined(tAttrs.onClick);
var clickAttr = isClickable ? 'ng-click="onClick({word : entry.word, id : entry.id})"' : '';
return "<div class='tangcloud'>" +
"<span ng-repeat='entry in words'" + clickAttr + ">{{entry.word}}</span>" +
"</div>";
},
compile: function (elem) {
elem.children().children()
.addClass('tangcloud-item-' + $interpolate.startSymbol() + 'entry.size' + $interpolate.endSymbol())
.addClass('tangcloud-item-hidden');
return function (scope, elem) {
var centerX = scope.width / 2;
var centerY = scope.height / 2;
var outOfBoundsCount = 0;
var takenSpots = [];
if (scope.words) {
scope.words = shuffleWords(scope.words);
determineWordPositions();
}
function shuffleWords(array) {
for (var i = array.length - 1; i > 0; i--) {
var j = Math.floor(Math.random() * (i + 1));
var temp = array[i];
array[i] = array[j];
array[j] = temp;
}
return array;
}
function determineWordPositions() {
$timeout(function () {
var trendSpans = elem.children().eq(0).children();
var length = trendSpans.length;
for (var i = 0; i < length; i++) {
setWordSpanPosition(trendSpans.eq(i));
}
});
}
function setWordSpanPosition(span) {
var height = parseInt(window.getComputedStyle(span[0]).lineHeight, 10);
var width = span[0].offsetWidth;
var spot = setupDefaultSpot(width, height);
var angleMultiplier = 0;
while (spotNotUsable(spot) && outOfBoundsCount < 50) {
spot = moveSpotOnSpiral(spot, angleMultiplier);
angleMultiplier += 1;
}
if (outOfBoundsCount < 50) {
takenSpots.push(spot);
addSpanPositionStyling(span, spot.startX, spot.startY);
}
outOfBoundsCount = 0;
}
function setupDefaultSpot(width, height) {
return {
width: width,
height: height,
startX: centerX - width / 2,
startY: centerY - height / 2,
endX: centerX + width / 2,
endY: centerY + height / 2
};
}
function moveSpotOnSpiral(spot, angleMultiplier) {
var angle = angleMultiplier * 0.1;
spot.startX = centerX + (1.5 * angle) * Math.cos(angle) - (spot.width / 2);
spot.startY = centerY + angle * Math.sin(angle) - (spot.height / 2);
spot.endX = spot.startX + spot.width;
spot.endY = spot.startY + spot.height;
return spot;
}
function spotNotUsable(spot) {
var borders = {
left: centerX - scope.width / 2,
right: centerX + scope.width / 2,
bottom: centerY - scope.height / 2,
top: centerY + scope.height / 2
};
for (var i = 0; i < takenSpots.length; i++) {
if (spotOutOfBounds(spot, borders) || collisionDetected(spot, takenSpots[i])) return true;
}
return false;
}
function spotOutOfBounds(spot, borders) {
if (spot.startX < borders.left ||
spot.endX > borders.right ||
spot.startY < borders.bottom ||
spot.endY > borders.top) {
outOfBoundsCount++;
return true;
} else {
return false;
}
}
function collisionDetected(spot, takenSpot) {
if (spot.startX > takenSpot.endX || spot.endX < takenSpot.startX) {
return false;
}
return !(spot.startY > takenSpot.endY || spot.endY < takenSpot.startY);
}
function addSpanPositionStyling(span, startX, startY) {
var style = "position: absolute; left:" + startX + "px; top: " + startY + "px;";
span.attr("style", style);
span.removeClass("tangcloud-item-hidden");
}
};
}
};
return directive;
}]);
tang-cloud指令被定义为tangCloud -以angular文档中的指令
为例app.js
.directive('myCustomer', function() {
return {
template: 'Name: {{customer.name}} Address: {{customer.address}}'
};
});
index . html
<div ng-controller="Controller">
<div my-customer></div>
</div>
请参阅本部分文档中的规范化一节。试着搜索'tangCloud'