From 8759ccddbdfa0283cb5c397512f84aafe1db0433 Mon Sep 17 00:00:00 2001
From: Rich Harris <richard.a.harris@gmail.com>
Date: Sat, 28 Apr 2018 18:48:07 -0400
Subject: [PATCH] simplify ssr

---
 src/generators/nodes/AwaitBlock.ts            |  9 ++--
 src/generators/nodes/Comment.ts               |  6 +--
 src/generators/nodes/Component.ts             | 40 ++++++++++++++----
 src/generators/nodes/EachBlock.ts             |  9 ++--
 src/generators/nodes/Element.ts               |  6 ++-
 src/generators/nodes/Head.ts                  |  8 ++--
 src/generators/nodes/IfBlock.ts               | 11 ++---
 src/generators/nodes/MustacheTag.ts           |  4 +-
 src/generators/nodes/RawMustacheTag.ts        |  4 +-
 src/generators/nodes/Slot.ts                  |  8 ++--
 src/generators/nodes/Text.ts                  |  4 +-
 src/generators/nodes/Title.ts                 |  8 ++--
 src/generators/server-side-rendering/Block.ts | 41 -------------------
 src/generators/server-side-rendering/index.ts | 10 +----
 .../server-side-rendering/interfaces.ts       | 14 -------
 src/interfaces.ts                             |  5 +++
 16 files changed, 75 insertions(+), 112 deletions(-)
 delete mode 100644 src/generators/server-side-rendering/Block.ts
 delete mode 100644 src/generators/server-side-rendering/interfaces.ts

diff --git a/src/generators/nodes/AwaitBlock.ts b/src/generators/nodes/AwaitBlock.ts
index 634b97d659..9178e53714 100644
--- a/src/generators/nodes/AwaitBlock.ts
+++ b/src/generators/nodes/AwaitBlock.ts
@@ -220,21 +220,20 @@ export default class AwaitBlock extends Node {
 		});
 	}
 
-	ssr(compiler, block) {
+	ssr() {
+		const { compiler } = this;
 		const { snippet } = this.expression;
 
-		const childBlock = block.child({});
-
 		compiler.append('${(function(__value) { if(@isPromise(__value)) return `');
 
 		this.pending.children.forEach((child: Node) => {
-			child.ssr(compiler, block);
+			child.ssr();
 		});
 
 		compiler.append('`; return function(ctx) { return `');
 
 		this.then.children.forEach((child: Node) => {
-			child.ssr(compiler, block);
+			child.ssr();
 		});
 
 		compiler.append(`\`;}(Object.assign({}, ctx, { ${this.value}: __value }));}(${snippet})) }`);
diff --git a/src/generators/nodes/Comment.ts b/src/generators/nodes/Comment.ts
index 4dfd493602..017011ed88 100644
--- a/src/generators/nodes/Comment.ts
+++ b/src/generators/nodes/Comment.ts
@@ -9,10 +9,10 @@ export default class Comment extends Node {
 		this.data = info.data;
 	}
 
-	ssr(compiler) {
+	ssr() {
 		// Allow option to preserve comments, otherwise ignore
-		if (compiler.options.preserveComments) {
-			compiler.append(`<!--${this.data}-->`);
+		if (this.compiler.options.preserveComments) {
+			this.compiler.append(`<!--${this.data}-->`);
 		}
 	}
 }
\ No newline at end of file
diff --git a/src/generators/nodes/Component.ts b/src/generators/nodes/Component.ts
index 2dc2a412b6..a6c0c9fb63 100644
--- a/src/generators/nodes/Component.ts
+++ b/src/generators/nodes/Component.ts
@@ -15,7 +15,7 @@ import mapChildren from './shared/mapChildren';
 import Binding from './Binding';
 import EventHandler from './EventHandler';
 import Expression from './shared/Expression';
-import { AppendTarget } from '../server-side-rendering/interfaces';
+import { AppendTarget } from '../../interfaces';
 
 export default class Component extends Node {
 	type: 'Component';
@@ -483,7 +483,7 @@ export default class Component extends Node {
 		return `${this.var}._mount(${name}._slotted.default, null);`;
 	}
 
-	ssr(compiler, block) {
+	ssr() {
 		function stringifyAttribute(chunk: Node) {
 			if (chunk.type === 'Text') {
 				return escapeTemplate(escape(chunk.data));
@@ -540,13 +540,35 @@ export default class Component extends Node {
 		const isDynamicComponent = this.name === 'svelte:component';
 
 		const expression = (
-			this.name === 'svelte:self' ? compiler.name :
+			this.name === 'svelte:self' ? this.compiler.name :
 			isDynamicComponent ? `((${this.expression.snippet}) || @missingComponent)` :
 			`%components-${this.name}`
 		);
 
 		this.bindings.forEach(binding => {
-			block.addBinding(binding, expression);
+			const conditions = [];
+
+			let node = this;
+			while (node = node.parent) {
+				if (node.type === 'IfBlock') {
+					// TODO handle contextual bindings...
+					conditions.push(`(${node.expression.snippet})`);
+				}
+			}
+
+			conditions.push(`!('${binding.name}' in ctx)`);
+
+			const { name } = getObject(binding.value.node);
+
+			this.compiler.bindings.push(deindent`
+				if (${conditions.reverse().join('&&')}) {
+					tmp = ${expression}.data();
+					if ('${name}' in tmp) {
+						ctx.${binding.name} = tmp.${name};
+						settled = false;
+					}
+				}
+			`);
 		});
 
 		let open = `\${${expression}._render(__result, ${props}`;
@@ -560,10 +582,10 @@ export default class Component extends Node {
 				slotStack: ['default']
 			};
 
-			compiler.appendTargets.push(appendTarget);
+			this.compiler.appendTargets.push(appendTarget);
 
 			this.children.forEach((child: Node) => {
-				child.ssr(compiler, block);
+				child.ssr();
 			});
 
 			const slotted = Object.keys(appendTarget.slots)
@@ -572,15 +594,15 @@ export default class Component extends Node {
 
 			options.push(`slotted: { ${slotted} }`);
 
-			compiler.appendTargets.pop();
+			this.compiler.appendTargets.pop();
 		}
 
 		if (options.length) {
 			open += `, { ${options.join(', ')} }`;
 		}
 
-		compiler.append(open);
-		compiler.append(')}');
+		this.compiler.append(open);
+		this.compiler.append(')}');
 	}
 }
 
diff --git a/src/generators/nodes/EachBlock.ts b/src/generators/nodes/EachBlock.ts
index 52f3869c5c..41ba3a5251 100644
--- a/src/generators/nodes/EachBlock.ts
+++ b/src/generators/nodes/EachBlock.ts
@@ -473,7 +473,8 @@ export default class EachBlock extends Node {
 		return `for (var #i = 0; #i < ${this.iterations}.length; #i += 1) ${this.iterations}[#i].m(${name}._slotted.default, null);`;
 	}
 
-	ssr(compiler, block) {
+	ssr() {
+		const { compiler } = this;
 		const { snippet } = this.expression;
 
 		const props = [`${this.context}: item`]
@@ -486,10 +487,8 @@ export default class EachBlock extends Node {
 		const open = `\${ ${this.else ? `${snippet}.length ? ` : ''}@each(${snippet}, ${getContext}, ctx => \``;
 		compiler.append(open);
 
-		const childBlock = block.child({});
-
 		this.children.forEach((child: Node) => {
-			child.ssr(compiler, childBlock);
+			child.ssr();
 		});
 
 		const close = `\`)`;
@@ -498,7 +497,7 @@ export default class EachBlock extends Node {
 		if (this.else) {
 			compiler.append(` : \``);
 			this.else.children.forEach((child: Node) => {
-				child.ssr(compiler, block);
+				child.ssr();
 			});
 			compiler.append(`\``);
 		}
diff --git a/src/generators/nodes/Element.ts b/src/generators/nodes/Element.ts
index 9e56deb2bf..4f9bd7f5ca 100644
--- a/src/generators/nodes/Element.ts
+++ b/src/generators/nodes/Element.ts
@@ -831,7 +831,9 @@ export default class Element extends Node {
 		}
 	}
 
-	ssr(compiler, block) {
+	ssr() {
+		const { compiler } = this;
+
 		let openingTag = `<${this.name}`;
 		let textareaContents; // awkward special case
 
@@ -902,7 +904,7 @@ export default class Element extends Node {
 			compiler.append(textareaContents);
 		} else {
 			this.children.forEach((child: Node) => {
-				child.ssr(compiler, block);
+				child.ssr();
 			});
 		}
 
diff --git a/src/generators/nodes/Head.ts b/src/generators/nodes/Head.ts
index e9d0ea041f..dc53e99613 100644
--- a/src/generators/nodes/Head.ts
+++ b/src/generators/nodes/Head.ts
@@ -36,13 +36,13 @@ export default class Head extends Node {
 		});
 	}
 
-	ssr(compiler, block) {
-		compiler.append('${(__result.head += `');
+	ssr() {
+		this.compiler.append('${(__result.head += `');
 
 		this.children.forEach((child: Node) => {
-			child.ssr(compiler, block);
+			child.ssr();
 		});
 
-		compiler.append('`, "")}');
+		this.compiler.append('`, "")}');
 	}
 }
diff --git a/src/generators/nodes/IfBlock.ts b/src/generators/nodes/IfBlock.ts
index 40a1ec46b6..b79b0b3a83 100644
--- a/src/generators/nodes/IfBlock.ts
+++ b/src/generators/nodes/IfBlock.ts
@@ -476,24 +476,21 @@ export default class IfBlock extends Node {
 		return branches;
 	}
 
-	ssr(compiler, block) {
+	ssr() {
+		const { compiler } = this;
 		const { snippet } = this.expression;
 
 		compiler.append('${ ' + snippet + ' ? `');
 
-		const childBlock = block.child({
-			conditions: block.conditions.concat(snippet),
-		});
-
 		this.children.forEach((child: Node) => {
-			child.ssr(compiler, childBlock);
+			child.ssr();
 		});
 
 		compiler.append('` : `');
 
 		if (this.else) {
 			this.else.children.forEach((child: Node) => {
-				child.ssr(compiler, block);
+				child.ssr();
 			});
 		}
 
diff --git a/src/generators/nodes/MustacheTag.ts b/src/generators/nodes/MustacheTag.ts
index 9547db2878..cad7a991ae 100644
--- a/src/generators/nodes/MustacheTag.ts
+++ b/src/generators/nodes/MustacheTag.ts
@@ -25,8 +25,8 @@ export default class MustacheTag extends Tag {
 		return `@appendNode(${this.var}, ${name}._slotted.default);`;
 	}
 
-	ssr(compiler) {
-		compiler.append(
+	ssr() {
+		this.compiler.append(
 			this.parent &&
 			this.parent.type === 'Element' &&
 			this.parent.name === 'style'
diff --git a/src/generators/nodes/RawMustacheTag.ts b/src/generators/nodes/RawMustacheTag.ts
index bee92f0fe4..00881bebd7 100644
--- a/src/generators/nodes/RawMustacheTag.ts
+++ b/src/generators/nodes/RawMustacheTag.ts
@@ -88,7 +88,7 @@ export default class RawMustacheTag extends Tag {
 		return `@appendNode(${this.var}, ${name}._slotted.default);`;
 	}
 
-	ssr(compiler) {
-		compiler.append('${' + this.expression.snippet + '}');
+	ssr() {
+		this.compiler.append('${' + this.expression.snippet + '}');
 	}
 }
\ No newline at end of file
diff --git a/src/generators/nodes/Slot.ts b/src/generators/nodes/Slot.ts
index c8b58c9b4d..0069fa9d8d 100644
--- a/src/generators/nodes/Slot.ts
+++ b/src/generators/nodes/Slot.ts
@@ -151,16 +151,16 @@ export default class Slot extends Element {
 		return null;
 	}
 
-	ssr(compiler, block) {
+	ssr() {
 		const name = this.attributes.find(attribute => attribute.name === 'name');
 		const slotName = name && name.chunks[0].data || 'default';
 
-		compiler.append(`\${options && options.slotted && options.slotted.${slotName} ? options.slotted.${slotName}() : \``);
+		this.compiler.append(`\${options && options.slotted && options.slotted.${slotName} ? options.slotted.${slotName}() : \``);
 
 		this.children.forEach((child: Node) => {
-			child.ssr(compiler, block);
+			child.ssr();
 		});
 
-		compiler.append(`\`}`);
+		this.compiler.append(`\`}`);
 	}
 }
\ No newline at end of file
diff --git a/src/generators/nodes/Text.ts b/src/generators/nodes/Text.ts
index 8a8c533366..5f9237c219 100644
--- a/src/generators/nodes/Text.ts
+++ b/src/generators/nodes/Text.ts
@@ -68,7 +68,7 @@ export default class Text extends Node {
 		return `@appendNode(${this.var}, ${name}._slotted.default);`;
 	}
 
-	ssr(compiler) {
+	ssr() {
 		let text = this.data;
 		if (
 			!this.parent ||
@@ -78,6 +78,6 @@ export default class Text extends Node {
 			// unless this Text node is inside a <script> or <style> element, escape &,<,>
 			text = escapeHTML(text);
 		}
-		compiler.append(escape(escapeTemplate(text)));
+		this.compiler.append(escape(escapeTemplate(text)));
 	}
 }
\ No newline at end of file
diff --git a/src/generators/nodes/Title.ts b/src/generators/nodes/Title.ts
index 48cc2263f5..51d5a1930b 100644
--- a/src/generators/nodes/Title.ts
+++ b/src/generators/nodes/Title.ts
@@ -102,13 +102,13 @@ export default class Title extends Node {
 		}
 	}
 
-	ssr(compiler, block) {
-		compiler.append(`<title>`);
+	ssr() {
+		this.compiler.append(`<title>`);
 
 		this.children.forEach((child: Node) => {
-			child.ssr(compiler, block);
+			child.ssr();
 		});
 
-		compiler.append(`</title>`);
+		this.compiler.append(`</title>`);
 	}
 }
\ No newline at end of file
diff --git a/src/generators/server-side-rendering/Block.ts b/src/generators/server-side-rendering/Block.ts
deleted file mode 100644
index 3743597a88..0000000000
--- a/src/generators/server-side-rendering/Block.ts
+++ /dev/null
@@ -1,41 +0,0 @@
-import deindent from '../../utils/deindent';
-import flattenReference from '../../utils/flattenReference';
-import { SsrGenerator } from './index';
-import { Node } from '../../interfaces';
-import getObject from '../../utils/getObject';
-
-interface BlockOptions {
-	// TODO
-}
-
-export default class Block {
-	generator: SsrGenerator;
-	conditions: string[];
-
-	constructor(options: BlockOptions) {
-		Object.assign(this, options);
-	}
-
-	addBinding(binding: Node, name: string) {
-		const conditions = [`!('${binding.name}' in ctx)`].concat(
-			// TODO handle contextual bindings...
-			this.conditions.map(c => `(${c})`)
-		);
-
-		const { name: prop } = getObject(binding.value.node);
-
-		this.generator.bindings.push(deindent`
-			if (${conditions.join('&&')}) {
-				tmp = ${name}.data();
-				if ('${prop}' in tmp) {
-					ctx.${binding.name} = tmp.${prop};
-					settled = false;
-				}
-			}
-		`);
-	}
-
-	child(options: BlockOptions) {
-		return new Block(Object.assign({}, this, options, { parent: this }));
-	}
-}
diff --git a/src/generators/server-side-rendering/index.ts b/src/generators/server-side-rendering/index.ts
index e6ec4fc3d9..04432cd4dc 100644
--- a/src/generators/server-side-rendering/index.ts
+++ b/src/generators/server-side-rendering/index.ts
@@ -2,13 +2,12 @@ import deindent from '../../utils/deindent';
 import Generator from '../Generator';
 import Stats from '../../Stats';
 import Stylesheet from '../../css/Stylesheet';
-import Block from './Block';
 import visit from './visit';
 import { removeNode, removeObjectKey } from '../../utils/removeNode';
 import getName from '../../utils/getName';
 import globalWhitelist from '../../utils/globalWhitelist';
 import { Ast, Node, CompileOptions } from '../../interfaces';
-import { AppendTarget } from './interfaces';
+import { AppendTarget } from '../../interfaces';
 import { stringify } from '../../utils/stringify';
 
 export class SsrGenerator extends Generator {
@@ -57,13 +56,8 @@ export default function ssr(
 	const { computations, name, templateProperties } = generator;
 
 	// create main render() function
-	const mainBlock = new Block({
-		generator,
-		conditions: [],
-	});
-
 	trim(generator.fragment.children).forEach((node: Node) => {
-		node.ssr(generator, mainBlock);
+		node.ssr();
 	});
 
 	const css = generator.customElement ?
diff --git a/src/generators/server-side-rendering/interfaces.ts b/src/generators/server-side-rendering/interfaces.ts
deleted file mode 100644
index 54b07be881..0000000000
--- a/src/generators/server-side-rendering/interfaces.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-import { SsrGenerator } from './index';
-import Block from './Block';
-import { Node } from '../../interfaces';
-
-export type Visitor = (
-	generator: SsrGenerator,
-	block: Block,
-	node: Node
-) => void;
-
-export interface AppendTarget {
-	slots: Record<string, string>;
-	slotStack: string[]
-}
\ No newline at end of file
diff --git a/src/interfaces.ts b/src/interfaces.ts
index 2405e81758..0c07debcfe 100644
--- a/src/interfaces.ts
+++ b/src/interfaces.ts
@@ -97,3 +97,8 @@ export interface PreprocessOptions {
 }
 
 export type Preprocessor = (options: {content: string, attributes: Record<string, string | boolean>, filename?: string}) => { code: string, map?: SourceMap | string };
+
+export interface AppendTarget {
+	slots: Record<string, string>;
+	slotStack: string[]
+}
\ No newline at end of file