/* @flow */
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import { addIfCondition } from 'compiler/parser/index'
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import { getAndRemoveAttr, addRawAttr } from 'compiler/helpers'
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function hasConditionDirective (el: ASTElement): boolean {
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for (const attr in el.attrsMap) {
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if (/^v\-if|v\-else|v\-else\-if$/.test(attr)) {
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return true
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}
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}
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return false
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}
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function getPreviousConditions (el: ASTElement): Array<string> {
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const conditions = []
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if (el.parent && el.parent.children) {
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for (let c = 0, n = el.parent.children.length; c < n; ++c) {
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// $flow-disable-line
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const ifConditions = el.parent.children[c].ifConditions
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if (ifConditions) {
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for (let i = 0, l = ifConditions.length; i < l; ++i) {
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const condition = ifConditions[i]
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if (condition && condition.exp) {
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conditions.push(condition.exp)
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}
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}
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}
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}
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}
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return conditions
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}
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export function preTransformVIf (el: ASTElement, options: WeexCompilerOptions) {
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if (hasConditionDirective(el)) {
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let exp
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const ifExp = getAndRemoveAttr(el, 'v-if', true /* remove from attrsMap */)
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const elseifExp = getAndRemoveAttr(el, 'v-else-if', true)
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// don't need the value, but remove it to avoid being generated as a
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// custom directive
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getAndRemoveAttr(el, 'v-else', true)
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if (ifExp) {
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exp = ifExp
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addIfCondition(el, { exp: ifExp, block: el })
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} else {
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elseifExp && addIfCondition(el, { exp: elseifExp, block: el })
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const prevConditions = getPreviousConditions(el)
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if (prevConditions.length) {
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const prevMatch = prevConditions.join(' || ')
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exp = elseifExp
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? `!(${prevMatch}) && (${elseifExp})` // v-else-if
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: `!(${prevMatch})` // v-else
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} else if (process.env.NODE_ENV !== 'production' && options.warn) {
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options.warn(
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`v-${elseifExp ? ('else-if="' + elseifExp + '"') : 'else'} ` +
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`used on element <${el.tag}> without corresponding v-if.`
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)
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return
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}
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}
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addRawAttr(el, '[[match]]', exp)
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}
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}
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