refactor mounting logic

src/generators/dom/Block.ts

@@ -130,15 +130,11 @@ export default class Block {
 		claimStatement: string,
 		parentNode: string
 	) {
-		const isToplevel = !parentNode;
-
 		this.addVariable(name);
 		this.builders.create.addLine(`${name} = ${renderStatement};`);
 		this.builders.claim.addLine(`${name} = ${claimStatement};`);
 
-		this.mount(name, parentNode);
-
-		if (isToplevel) {
+		if (!parentNode) {
 			this.builders.unmount.addLine(`@detachNode(${name});`);
 		}
 	}
@@ -182,14 +178,6 @@ export default class Block {
 		);
 	}
 
-	mount(name: string, parentNode: string) {
-		if (parentNode) {
-			this.builders.mount.addLine(`@appendNode(${name}, ${parentNode});`);
-		} else {
-			this.builders.mount.addLine(`@insertNode(${name}, #target, anchor);`);
-		}
-	}
-
 	toString() {
 		let introing;
 		const hasIntros = !this.builders.intro.isEmpty();
@@ -223,6 +211,7 @@ export default class Block {
 		if (this.first) {
 			properties.addBlock(`first: null,`);
 			this.builders.hydrate.addLine(`this.first = ${this.first};`);
+			this.builders.mount.addLineAtStart(`@insertNode(${this.first}, #target, anchor);`);
 		}
 
 		if (this.builders.create.isEmpty()) {

src/generators/dom/index.ts

@@ -13,6 +13,7 @@ import Generator from '../Generator';
 import Stylesheet from '../../css/Stylesheet';
 import preprocess from './preprocess';
 import Block from './Block';
+import mountChildren from './mountChildren';
 import { version } from '../../../package.json';
 import { Parsed, CompileOptions, Node } from '../../interfaces';
 
@@ -105,6 +106,8 @@ export default function dom(
 		visit(generator, block, state, node, [], []);
 	});
 
+	block.builders.mount.addBlock(mountChildren(parsed.html));
+
 	const builder = new CodeBuilder();
 	const computationBuilder = new CodeBuilder();
 	const computationDeps = new Set();

src/generators/dom/mountChildren.ts

@@ -0,0 +1,30 @@
+import CodeBuilder from '../../utils/CodeBuilder';
+import { Node } from '../../interfaces';
+import Block from './Block';
+
+export default function mountChildren(node: Node, parentNode?: string) {
+	const builder = new CodeBuilder();
+
+	node.children.forEach((child: Node) => {
+		if (child.mountStatement) {
+			// TODO determining whether to use line or block should probably
+			// happen inside CodeBuilder
+			if (/\n/.test(child.mountStatement)) {
+				builder.addBlock(child.mountStatement);
+			} else {
+				builder.addLine(child.mountStatement);
+			}
+		} else {
+			if (child.shouldSkip) return;
+			if (child.type === 'Element' && child.name === ':Window') return;
+
+			if (parentNode) {
+				builder.addLine(`@appendNode(${child.var}, ${parentNode});`);
+			} else {
+				builder.addLine(`@insertNode(${child.var}, #target, anchor);`);
+			}
+		}
+	});
+
+	return builder;
+}

src/generators/dom/visitors/Component.ts

@@ -3,6 +3,7 @@ import CodeBuilder from '../../../utils/CodeBuilder';
 import visit from '../visit';
 import { DomGenerator } from '../index';
 import Block from '../Block';
+import mountChildren from '../mountChildren';
 import getTailSnippet from '../../../utils/getTailSnippet';
 import getObject from '../../../utils/getObject';
 import getExpressionPrecedence from '../../../utils/getExpressionPrecedence';
@@ -60,6 +61,8 @@ export default function visitComponent(
 		node.children.forEach((child: Node) => {
 			visit(generator, block, node._state, child, elementStack, componentStack.concat(node));
 		});
+
+		block.builders.mount.addBlock(mountChildren(node, node._state.parentNode));
 	}
 
 	const allContexts = new Set();
@@ -233,7 +236,7 @@ export default function visitComponent(
 		`${name}._fragment.l( ${state.parentNodes} );`
 	);
 
-	block.builders.mount.addLine(
+	node.mountStatement = (
 		`${name}._mount(${state.parentNode || '#target'}, ${state.parentNode ? 'null' : 'anchor'});`
 	);
 

src/generators/dom/visitors/EachBlock.ts

@@ -2,6 +2,7 @@ import deindent from '../../../utils/deindent';
 import visit from '../visit';
 import { DomGenerator } from '../index';
 import Block from '../Block';
+import mountChildren from '../mountChildren';
 import isDomNode from './shared/isDomNode';
 import { Node } from '../../../interfaces';
 import { State } from '../interfaces';
@@ -79,11 +80,11 @@ export default function visitEachBlock(
 			}
 		`);
 
-		block.builders.mount.addBlock(deindent`
+		node.mountStatement += '\n\n' + deindent`
 			if (${each_block_else}) {
 				${each_block_else}.${mountOrIntro}(${state.parentNode || '#target'}, null);
 			}
-		`);
+		`;
 
 		const parentNode = state.parentNode || `${anchor}.parentNode`;
 
@@ -126,14 +127,23 @@ export default function visitEachBlock(
 		`);
 	}
 
+	// TODO do this elsewhere?
+	if (needsAnchor) node.mountStatement += '\n\n' + (
+		state.parentNode ? `@appendNode(${anchor}, ${state.parentNode});` : `@insertNode(${anchor}, #target, anchor);`
+	);
+
 	node.children.forEach((child: Node) => {
 		visit(generator, node._block, node._state, child, elementStack, componentStack);
 	});
 
+	node._block.builders.mount.addBlock(mountChildren(node));
+
 	if (node.else) {
 		node.else.children.forEach((child: Node) => {
 			visit(generator, node.else._block, node.else._state, child, elementStack, componentStack);
 		});
+
+		node.else._block.builders.mount.addBlock(mountChildren(node.else));
 	}
 }
 
@@ -164,6 +174,8 @@ function keyed(
 	block.addVariable(head);
 	block.addVariable(last);
 
+	let first;
+
 	if (node.children[0] && node.children[0].type === 'Element' && !generator.components.has(node.children[0].name)) {
 		// TODO or text/tag/raw
 		node._block.first = node.children[0]._state.parentNode; // TODO this is highly confusing
@@ -209,13 +221,13 @@ function keyed(
 		}
 	`);
 
-	block.builders.mount.addBlock(deindent`
+	node.mountStatement = deindent`
 		var ${iteration} = ${head};
 		while (${iteration}) {
 			${iteration}.${mountOrIntro}(${targetNode}, ${anchorNode});
 			${iteration} = ${iteration}.next;
 		}
-	`);
+	`;
 
 	const dynamic = node._block.hasUpdateMethod;
 	const parentNode = state.parentNode || `${anchor}.parentNode`;
@@ -396,11 +408,11 @@ function unkeyed(
 		}
 	`);
 
-	block.builders.mount.addBlock(deindent`
+	node.mountStatement = deindent`
 		for (var #i = 0; #i < ${iterations}.length; #i += 1) {
 			${iterations}[#i].${mountOrIntro}(${targetNode}, ${anchorNode});
 		}
-	`);
+	`;
 
 	const dependencies = block.findDependencies(node.expression);
 	const allDependencies = new Set(node._block.dependencies);

src/generators/dom/visitors/Element/Element.ts

@@ -13,6 +13,7 @@ import isVoidElementName from '../../../../utils/isVoidElementName';
 import addTransitions from './addTransitions';
 import { DomGenerator } from '../../index';
 import Block from '../../Block';
+import mountChildren from '../../mountChildren';
 import { Node } from '../../../../interfaces';
 import { State } from '../../interfaces';
 import reservedNames from '../../../../utils/reservedNames';
@@ -86,12 +87,10 @@ export default function visitElement(
 		`);
 	}
 
-	if (parentNode) {
-		block.builders.mount.addLine(
-			`@appendNode(${name}, ${parentNode});`
-		);
-	} else {
-		block.builders.mount.addLine(`@insertNode(${name}, #target, anchor);`);
+	// TODO this is kinda messy — this is a hack to prevent the mount statement
+	// going in the usual place
+	if (node.slotted) {
+		node.mountStatement = `@appendNode(${node.var}, ${parentNode});`;
 	}
 
 	// add CSS encapsulation attribute
@@ -216,6 +215,8 @@ export default function visitElement(
 		node.children.forEach((child: Node) => {
 			visit(generator, block, childState, child, elementStack.concat(node), componentStack);
 		});
+
+		block.builders.mount.addBlock(mountChildren(node, node.var));
 	}
 
 	if (node.lateUpdate) {

src/generators/dom/visitors/IfBlock.ts

@@ -2,6 +2,7 @@ import deindent from '../../../utils/deindent';
 import visit from '../visit';
 import { DomGenerator } from '../index';
 import Block from '../Block';
+import mountChildren from '../mountChildren';
 import isDomNode from './shared/isDomNode';
 import { Node } from '../../../interfaces';
 import { State } from '../interfaces';
@@ -68,6 +69,8 @@ function visitChildren(
 	node.children.forEach((child: Node) => {
 		visit(generator, node._block, node._state, child, elementStack, componentStack);
 	});
+
+	node._block.builders.mount.addBlock(mountChildren(node));
 }
 
 export default function visitIfBlock(
@@ -127,6 +130,11 @@ export default function visitIfBlock(
 			`@createComment()`,
 			state.parentNode
 		);
+
+		// TODO do this elsewhere?
+		node.mountStatement += '\n\n' + (
+			state.parentNode ? `@appendNode(${anchor}, ${state.parentNode})` : `@insertNode(${anchor}, #target, anchor)`
+		);
 	}
 }
 
@@ -148,7 +156,7 @@ function simple(
 	const targetNode = state.parentNode || '#target';
 	const anchorNode = state.parentNode ? 'null' : 'anchor';
 
-	block.builders.mount.addLine(
+	node.mountStatement = (
 		`if (${name}) ${name}.${mountOrIntro}(${targetNode}, ${anchorNode});`
 	);
 
@@ -251,7 +259,8 @@ function compound(
 
 	const targetNode = state.parentNode || '#target';
 	const anchorNode = state.parentNode ? 'null' : 'anchor';
-	block.builders.mount.addLine(
+
+	node.mountStatement = (
 		`${if_name}${name}.${mountOrIntro}(${targetNode}, ${anchorNode});`
 	);
 
@@ -350,7 +359,7 @@ function compoundWithOutros(
 	const targetNode = state.parentNode || '#target';
 	const anchorNode = state.parentNode ? 'null' : 'anchor';
 
-	block.builders.mount.addLine(
+	node.mountStatement = (
 		`${if_current_block_type_index}${if_blocks}[${current_block_type_index}].${mountOrIntro}(${targetNode}, ${anchorNode});`
 	);
 

src/generators/dom/visitors/RawMustacheTag.ts

@@ -55,8 +55,8 @@ export default function visitRawMustacheTag(
 		`
 	);
 
-	// we would have used comments here, but the `insertAdjacentHTML` api only
-	// exists for `Element`s.
+	let mountStatements: string[] = [];
+
 	if (needsAnchorBefore) {
 		block.addElement(
 			anchorBefore,
@@ -64,6 +64,10 @@ export default function visitRawMustacheTag(
 			`@createElement('noscript')`,
 			state.parentNode
 		);
+
+		mountStatements.push(
+			state.parentNode ? `@appendNode(${anchorBefore}, ${state.parentNode});` : `@insertNode(${anchorBefore}, #target, anchor);`
+		);
 	}
 
 	function addAnchorAfter() {
@@ -73,19 +77,17 @@ export default function visitRawMustacheTag(
 			`@createElement('noscript')`,
 			state.parentNode
 		);
-	}
 
-	if (needsAnchorAfter && anchorBefore === 'null') {
-		// anchorAfter needs to be in the DOM before we
-		// insert the HTML...
-		addAnchorAfter();
+		mountStatements.push(
+			state.parentNode ? `@appendNode(${anchorAfter}, ${state.parentNode});` : `@insertNode(${anchorAfter}, #target, anchor);`
+		);
 	}
 
-	block.builders.mount.addLine(insert(init));
-	block.builders.detachRaw.addBlock(detach);
+	if (needsAnchorAfter && anchorBefore === 'null') addAnchorAfter();
+	mountStatements.push(insert(init));
+	if (needsAnchorAfter && anchorBefore !== 'null') addAnchorAfter();
 
-	if (needsAnchorAfter && anchorBefore !== 'null') {
-		// ...otherwise it should go afterwards
-		addAnchorAfter();
-	}
+	node.mountStatement = mountStatements.join('\n');
+
+	block.builders.detachRaw.addBlock(detach);
 }

src/generators/dom/visitors/Slot.ts

@@ -2,6 +2,7 @@ import { DomGenerator } from '../index';
 import deindent from '../../../utils/deindent';
 import visit from '../visit';
 import Block from '../Block';
+import mountChildren from '../mountChildren';
 import getStaticAttributeValue from '../../../utils/getStaticAttributeValue';
 import { Node } from '../../../interfaces';
 import { State } from '../interfaces';
@@ -34,39 +35,30 @@ export default function visitSlot(
 	if (needsAnchorBefore) block.addVariable(anchorBefore);
 	if (needsAnchorAfter) block.addVariable(anchorAfter);
 
-	block.builders.create.pushCondition(`!${content_name}`);
-	block.builders.hydrate.pushCondition(`!${content_name}`);
-	block.builders.mount.pushCondition(`!${content_name}`);
-	block.builders.unmount.pushCondition(`!${content_name}`);
-	block.builders.destroy.pushCondition(`!${content_name}`);
-
 	node.children.forEach((child: Node) => {
 		visit(generator, block, state, child, elementStack, componentStack);
 	});
 
-	block.builders.create.popCondition();
-	block.builders.hydrate.popCondition();
-	block.builders.mount.popCondition();
-	block.builders.unmount.popCondition();
-	block.builders.destroy.popCondition();
-
-	// TODO can we use an else here?
 	if (state.parentNode) {
-		block.builders.mount.addBlock(deindent`
+		node.mountStatement = deindent`
 			if (${content_name}) {
 				${needsAnchorBefore && `@appendNode(${anchorBefore} || (${anchorBefore} = @createComment()), ${state.parentNode});`}
 				@appendNode(${content_name}, ${state.parentNode});
 				${needsAnchorAfter && `@appendNode(${anchorAfter} || (${anchorAfter} = @createComment()), ${state.parentNode});`}
+			} else {
+				${mountChildren(node, state.parentNode)}
 			}
-		`);
+		`;
 	} else {
-		block.builders.mount.addBlock(deindent`
+		node.mountStatement = deindent`
 			if (${content_name}) {
 				${needsAnchorBefore && `@insertNode(${anchorBefore} || (${anchorBefore} = @createComment()), #target, anchor);`}
 				@insertNode(${content_name}, #target, anchor);
 				${needsAnchorAfter && `@insertNode(${anchorAfter} || (${anchorAfter} = @createComment()), #target, anchor);`}
+			} else {
+				${mountChildren(node, state.parentNode)}
 			}
-		`);
+		`;
 	}
 
 	// if the slot is unmounted, move nodes back into the document fragment,

src/utils/CodeBuilder.ts

@@ -51,7 +51,12 @@ export default class CodeBuilder {
 		this.last = ChunkType.Block;
 	}
 
-	addLine(line: string) {
+	addLine(line: string | CodeBuilder) {
+		if (line instanceof CodeBuilder) {
+			if (!line.isEmpty()) this.addLine(line.toString());
+			return;
+		}
+
 		this.reifyConditions();
 
 		if (this.lastCondition) {
@@ -71,7 +76,12 @@ export default class CodeBuilder {
 		if (!this.first) this.first = ChunkType.Line;
 	}
 
-	addLineAtStart(line: string) {
+	addLineAtStart(line: string | CodeBuilder) {
+		if (line instanceof CodeBuilder) {
+			if (!line.isEmpty()) this.addLineAtStart(line.toString());
+			return;
+		}
+
 		this.reifyConditions();
 
 		if (this.first === ChunkType.Block) {
@@ -86,7 +96,12 @@ export default class CodeBuilder {
 		if (!this.last) this.last = ChunkType.Line;
 	}
 
-	addBlock(block: string) {
+	addBlock(block: string | CodeBuilder) {
+		if (block instanceof CodeBuilder) {
+			if (!block.isEmpty()) this.addBlock(block.toString());
+			return;
+		}
+
 		this.reifyConditions();
 
 		if (this.indent) block = block.replace(/^/gm, `${this.indent}`);
@@ -106,7 +121,12 @@ export default class CodeBuilder {
 		if (!this.first) this.first = ChunkType.Block;
 	}
 
-	addBlockAtStart(block: string) {
+	addBlockAtStart(block: string | CodeBuilder) {
+		if (block instanceof CodeBuilder) {
+			if (!block.isEmpty()) this.addBlockAtStart(block.toString());
+			return;
+		}
+
 		this.reifyConditions();
 
 		if (this.result) {