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node_modules/@riotjs/dom-bindings/src/bindings/if.js

@@ -0,0 +1,65 @@
+import {insertBefore, removeChild} from '@riotjs/util/dom'
+
+/**
+ * Binding responsible for the `if` directive
+ */
+export const IfBinding = {
+  // dynamic binding properties
+  // node: null,
+  // evaluate: null,
+  // isTemplateTag: false,
+  // placeholder: null,
+  // template: null,
+
+  // API methods
+  mount(scope, parentScope) {
+    return this.update(scope, parentScope)
+  },
+  update(scope, parentScope) {
+    const value = !!this.evaluate(scope)
+    const mustMount = !this.value && value
+    const mustUnmount = this.value && !value
+    const mount = () => {
+      const pristine = this.node.cloneNode()
+
+      insertBefore(pristine, this.placeholder)
+      this.template = this.template.clone()
+      this.template.mount(pristine, scope, parentScope)
+    }
+
+    switch (true) {
+    case mustMount:
+      mount()
+      break
+    case mustUnmount:
+      this.unmount(scope)
+      break
+    default:
+      if (value) this.template.update(scope, parentScope)
+    }
+
+    this.value = value
+
+    return this
+  },
+  unmount(scope, parentScope) {
+    this.template.unmount(scope, parentScope, true)
+
+    return this
+  }
+}
+
+export default function create(node, { evaluate, template }) {
+  const placeholder = document.createTextNode('')
+
+  insertBefore(placeholder, node)
+  removeChild(node)
+
+  return {
+    ...IfBinding,
+    node,
+    evaluate,
+    placeholder,
+    template: template.createDOM(node)
+  }
+}