visible.js

var update = require('./_update')

var none = 'none'
function parseDisplay(elem, val) {
    //用于取得此类标签的默认display值
    var doc = elem.ownerDocument
    var nodeName = elem.nodeName
    var key = '_' + nodeName
    if (!parseDisplay[key]) {
        var temp = doc.body.appendChild(doc.createElement(nodeName))
        val = avalon.css(temp, 'display')
        doc.body.removeChild(temp)
        if (val === none) {
            val = 'block'
        }
        parseDisplay[key] = val
    }
    return parseDisplay[key]
}

avalon.parseDisplay = parseDisplay

avalon.directive('visible', {
    diff: function (copy, src, name) {
        var c = !!copy[name]
        if (!src.dynamic[name] || c !== src[name]) {
            src[name] = c
            update(src, this.update)
        }
    },
    update: function (dom, vdom) {
        if (dom && dom.nodeType === 1) {
            vdom.dynamic['ms-visible'] = 1
            var show = vdom['ms-visible']
            var display = dom.style.display
            var value
            if (show) {
                if (display === none) {
                    value = vdom.displayValue
                    if (!value) {
                        dom.style.display = ''
                    }
                }
                if (dom.style.display === '' && avalon(dom).css('display') === none &&
                        // fix firefox BUG,必须挂到页面上
                        avalon.contains(dom.ownerDocument, dom)) {

                    value = parseDisplay(dom)
                }
            } else {
                if (display !== none) {
                    value = none
                    vdom.displayValue = display
                }
            }
            function cb() {
                if (value !== void 0) {
                    dom.style.display = value
                }
            }
            avalon.applyEffect(dom, vdom, {
                hook: show ? 'onEnterDone' : 'onLeaveDone',
                cb: cb
            })
        }

    }
})