svelte/src/compile/render-dom/wrappers/IfBlock.ts

473 lines
12 KiB

import Wrapper from './shared/Wrapper';
import Renderer from '../Renderer';
import Block from '../Block';
import EachBlock from '../../nodes/EachBlock';
import IfBlock from '../../nodes/IfBlock';
import createDebuggingComment from '../../../utils/createDebuggingComment';
import ElseBlock from '../../nodes/ElseBlock';
import FragmentWrapper from './Fragment';
import deindent from '../../../utils/deindent';
function isElseIf(node: ElseBlock) {
return (
node && node.children.length === 1 && node.children[0].type === 'IfBlock'
);
}
class IfBlockBranch extends Wrapper {
block: Block;
fragment: FragmentWrapper;
condition: string;
isDynamic: boolean;
var = null;
constructor(
renderer: Renderer,
block: Block,
parent: IfBlockWrapper,
node: IfBlock | ElseBlock,
stripWhitespace: boolean,
nextSibling: Wrapper
) {
super(renderer, block, parent, node);
this.condition = (<IfBlock>node).expression && (<IfBlock>node).expression.snippet;
this.block = block.child({
comment: createDebuggingComment(node, parent.renderer.component),
name: parent.renderer.component.getUniqueName(
(<IfBlock>node).expression ? `create_if_block` : `create_else_block`
)
});
this.fragment = new FragmentWrapper(renderer, this.block, node.children, parent, stripWhitespace, nextSibling);
this.isDynamic = this.block.dependencies.size > 0;
}
}
export default class IfBlockWrapper extends Wrapper {
node: IfBlock;
branches: IfBlockBranch[];
var = 'if_block';
constructor(
renderer: Renderer,
block: Block,
parent: Wrapper,
node: EachBlock,
stripWhitespace: boolean,
nextSibling: Wrapper
) {
super(renderer, block, parent, node);
const { component } = renderer;
this.cannotUseInnerHTML();
this.branches = [];
const blocks: Block[] = [];
let isDynamic = false;
let hasIntros = false;
let hasOutros = false;
const createBranches = (node: IfBlock) => {
const branch = new IfBlockBranch(
renderer,
block,
this,
node,
stripWhitespace,
nextSibling
);
this.branches.push(branch);
blocks.push(branch.block);
block.addDependencies(node.expression.dependencies);
if (branch.block.dependencies.size > 0) {
isDynamic = true;
block.addDependencies(branch.block.dependencies);
}
if (branch.block.hasIntros) hasIntros = true;
if (branch.block.hasOutros) hasOutros = true;
if (isElseIf(node.else)) {
createBranches(node.else.children[0]);
} else if (node.else) {
const branch = new IfBlockBranch(
renderer,
block,
this,
node.else,
stripWhitespace,
nextSibling
);
this.branches.push(branch);
blocks.push(branch.block);
if (branch.block.dependencies.size > 0) {
isDynamic = true;
block.addDependencies(branch.block.dependencies);
}
if (branch.block.hasIntros) hasIntros = true;
if (branch.block.hasOutros) hasOutros = true;
}
};
createBranches(this.node);
if (component.options.nestedTransitions) {
if (hasIntros) block.addIntro();
if (hasOutros) block.addOutro();
}
blocks.forEach(block => {
block.hasUpdateMethod = isDynamic;
block.hasIntroMethod = hasIntros;
block.hasOutroMethod = hasOutros;
});
renderer.blocks.push(...blocks);
}
render(
block: Block,
parentNode: string,
parentNodes: string
) {
const name = this.var;
const needsAnchor = this.next ? !this.next.isDomNode() : !parentNode || !this.parent.isDomNode();
const anchor = needsAnchor
? block.getUniqueName(`${name}_anchor`)
: (this.next && this.next.var) || 'null';
const hasElse = !(this.branches[this.branches.length - 1].condition);
const if_name = hasElse ? '' : `if (${name}) `;
const dynamic = this.branches[0].block.hasUpdateMethod; // can use [0] as proxy for all, since they necessarily have the same value
const hasOutros = this.branches[0].block.hasOutroMethod;
const vars = { name, anchor, if_name, hasElse };
if (this.node.else) {
if (hasOutros) {
this.renderCompoundWithOutros(block, parentNode, parentNodes, dynamic, vars);
if (this.renderer.options.nestedTransitions) {
block.builders.outro.addBlock(deindent`
if (${name}) ${name}.o(#outrocallback);
else #outrocallback();
`);
}
} else {
this.renderCompound(block, parentNode, parentNodes, dynamic, vars);
}
} else {
this.renderSimple(block, parentNode, parentNodes, dynamic, vars);
if (hasOutros && this.renderer.options.nestedTransitions) {
block.builders.outro.addBlock(deindent`
if (${name}) ${name}.o(#outrocallback);
else #outrocallback();
`);
}
}
block.builders.create.addLine(`${if_name}${name}.c();`);
if (parentNodes) {
block.builders.claim.addLine(
`${if_name}${name}.l(${parentNodes});`
);
}
if (needsAnchor) {
block.addElement(
anchor,
`@createComment()`,
parentNodes && `@createComment()`,
parentNode
);
}
this.branches.forEach(branch => {
branch.fragment.render(branch.block, null, 'nodes');
});
}
renderCompound(
block: Block,
parentNode: string,
parentNodes: string,
dynamic,
{ name, anchor, hasElse, if_name }
) {
const select_block_type = this.renderer.component.getUniqueName(`select_block_type`);
const current_block_type = block.getUniqueName(`current_block_type`);
const current_block_type_and = hasElse ? '' : `${current_block_type} && `;
block.builders.init.addBlock(deindent`
function ${select_block_type}(ctx) {
${this.branches
.map(({ condition, block }) => `${condition ? `if (${condition}) ` : ''}return ${block.name};`)
.join('\n')}
}
`);
block.builders.init.addBlock(deindent`
var ${current_block_type} = ${select_block_type}(ctx);
var ${name} = ${current_block_type_and}${current_block_type}(#component, ctx);
`);
const mountOrIntro = this.branches[0].block.hasIntroMethod ? 'i' : 'm';
const initialMountNode = parentNode || '#target';
const anchorNode = parentNode ? 'null' : 'anchor';
block.builders.mount.addLine(
`${if_name}${name}.${mountOrIntro}(${initialMountNode}, ${anchorNode});`
);
const updateMountNode = this.getUpdateMountNode(anchor);
const changeBlock = deindent`
${if_name}${name}.d(1);
${name} = ${current_block_type_and}${current_block_type}(#component, ctx);
${if_name}${name}.c();
${if_name}${name}.${mountOrIntro}(${updateMountNode}, ${anchor});
`;
if (dynamic) {
block.builders.update.addBlock(deindent`
if (${current_block_type} === (${current_block_type} = ${select_block_type}(ctx)) && ${name}) {
${name}.p(changed, ctx);
} else {
${changeBlock}
}
`);
} else {
block.builders.update.addBlock(deindent`
if (${current_block_type} !== (${current_block_type} = ${select_block_type}(ctx))) {
${changeBlock}
}
`);
}
block.builders.destroy.addLine(`${if_name}${name}.d(${parentNode ? '' : 'detach'});`);
}
// if any of the siblings have outros, we need to keep references to the blocks
// (TODO does this only apply to bidi transitions?)
renderCompoundWithOutros(
block: Block,
parentNode: string,
parentNodes: string,
dynamic,
{ name, anchor, hasElse }
) {
const select_block_type = this.renderer.component.getUniqueName(`select_block_type`);
const current_block_type_index = block.getUniqueName(`current_block_type_index`);
const previous_block_index = block.getUniqueName(`previous_block_index`);
const if_block_creators = block.getUniqueName(`if_block_creators`);
const if_blocks = block.getUniqueName(`if_blocks`);
const if_current_block_type_index = hasElse
? ''
: `if (~${current_block_type_index}) `;
block.addVariable(current_block_type_index);
block.addVariable(name);
block.builders.init.addBlock(deindent`
var ${if_block_creators} = [
${this.branches.map(branch => branch.block.name).join(',\n')}
];
var ${if_blocks} = [];
function ${select_block_type}(ctx) {
${this.branches
.map(({ condition }, i) => `${condition ? `if (${condition}) ` : ''}return ${i};`)
.join('\n')}
${!hasElse && `return -1;`}
}
`);
if (hasElse) {
block.builders.init.addBlock(deindent`
${current_block_type_index} = ${select_block_type}(ctx);
${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](#component, ctx);
`);
} else {
block.builders.init.addBlock(deindent`
if (~(${current_block_type_index} = ${select_block_type}(ctx))) {
${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](#component, ctx);
}
`);
}
const mountOrIntro = this.branches[0].block.hasIntroMethod ? 'i' : 'm';
const initialMountNode = parentNode || '#target';
const anchorNode = parentNode ? 'null' : 'anchor';
block.builders.mount.addLine(
`${if_current_block_type_index}${if_blocks}[${current_block_type_index}].${mountOrIntro}(${initialMountNode}, ${anchorNode});`
);
const updateMountNode = this.getUpdateMountNode(anchor);
const destroyOldBlock = deindent`
@groupOutros();
${name}.o(function() {
${if_blocks}[${previous_block_index}].d(1);
${if_blocks}[${previous_block_index}] = null;
});
`;
const createNewBlock = deindent`
${name} = ${if_blocks}[${current_block_type_index}];
if (!${name}) {
${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](#component, ctx);
${name}.c();
}
${name}.${mountOrIntro}(${updateMountNode}, ${anchor});
`;
const changeBlock = hasElse
? deindent`
${destroyOldBlock}
${createNewBlock}
`
: deindent`
if (${name}) {
${destroyOldBlock}
}
if (~${current_block_type_index}) {
${createNewBlock}
} else {
${name} = null;
}
`;
if (dynamic) {
block.builders.update.addBlock(deindent`
var ${previous_block_index} = ${current_block_type_index};
${current_block_type_index} = ${select_block_type}(ctx);
if (${current_block_type_index} === ${previous_block_index}) {
${if_current_block_type_index}${if_blocks}[${current_block_type_index}].p(changed, ctx);
} else {
${changeBlock}
}
`);
} else {
block.builders.update.addBlock(deindent`
var ${previous_block_index} = ${current_block_type_index};
${current_block_type_index} = ${select_block_type}(ctx);
if (${current_block_type_index} !== ${previous_block_index}) {
${changeBlock}
}
`);
}
block.builders.destroy.addLine(deindent`
${if_current_block_type_index}${if_blocks}[${current_block_type_index}].d(${parentNode ? '' : 'detach'});
`);
}
renderSimple(
block: Block,
parentNode: string,
parentNodes: string,
dynamic,
{ name, anchor, if_name }
) {
const branch = this.branches[0];
block.builders.init.addBlock(deindent`
var ${name} = (${branch.condition}) && ${branch.block.name}(#component, ctx);
`);
const mountOrIntro = branch.block.hasIntroMethod ? 'i' : 'm';
const initialMountNode = parentNode || '#target';
const anchorNode = parentNode ? 'null' : 'anchor';
block.builders.mount.addLine(
`if (${name}) ${name}.${mountOrIntro}(${initialMountNode}, ${anchorNode});`
);
const updateMountNode = this.getUpdateMountNode(anchor);
const enter = dynamic
? (branch.block.hasIntroMethod || branch.block.hasOutroMethod)
? deindent`
if (${name}) {
${name}.p(changed, ctx);
} else {
${name} = ${branch.block.name}(#component, ctx);
if (${name}) ${name}.c();
}
${name}.i(${updateMountNode}, ${anchor});
`
: deindent`
if (${name}) {
${name}.p(changed, ctx);
} else {
${name} = ${branch.block.name}(#component, ctx);
${name}.c();
${name}.m(${updateMountNode}, ${anchor});
}
`
: (branch.block.hasIntroMethod || branch.block.hasOutroMethod)
? deindent`
if (!${name}) {
${name} = ${branch.block.name}(#component, ctx);
${name}.c();
}
${name}.i(${updateMountNode}, ${anchor});
`
: deindent`
if (!${name}) {
${name} = ${branch.block.name}(#component, ctx);
${name}.c();
${name}.m(${updateMountNode}, ${anchor});
}
`;
// no `p()` here — we don't want to update outroing nodes,
// as that will typically result in glitching
const exit = branch.block.hasOutroMethod
? deindent`
@groupOutros();
${name}.o(function() {
${name}.d(1);
${name} = null;
});
`
: deindent`
${name}.d(1);
${name} = null;
`;
block.builders.update.addBlock(deindent`
if (${branch.condition}) {
${enter}
} else if (${name}) {
${exit}
}
`);
block.builders.destroy.addLine(`${if_name}${name}.d(${parentNode ? '' : 'detach'});`);
}
}