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svelte/src/compiler/compile/render_dom/wrappers/IfBlock.ts

692 lines
22 KiB

import Wrapper from './shared/Wrapper.js';
import create_debugging_comment from './shared/create_debugging_comment.js';
import FragmentWrapper from './Fragment.js';
import { b, x } from 'code-red';
import { walk } from 'estree-walker';
import { is_head } from './shared/is_head.js';
import { push_array } from '../../../utils/push_array.js';
import { add_const_tags, add_const_tags_context } from './shared/add_const_tags.js';
/** @param {import('../../nodes/ElseBlock.js').default} node */
function is_else_if(node) {
return node && node.children.length === 1 && node.children[0].type === 'IfBlock';
}
/** @extends Wrapper<import('../../nodes/IfBlock.js').default | import('../../nodes/ElseBlock.js').default> */
class IfBlockBranch extends Wrapper {
/** @type {import('../Block.js').default} */
block;
/** @type {import('./Fragment.js').default} */
fragment;
/** @type {string[]} */
dependencies;
/** @type {any} */
condition;
/** @type {import('estree').Node} */
snippet;
/** @type {boolean} */
is_dynamic;
/** */
var = null;
/** @type {import('estree').Node | undefined} */
get_ctx_name;
/**
* @param {import('../Renderer.js').default} renderer
* @param {import('../Block.js').default} block
* @param {IfBlockWrapper} parent
* @param {import('../../nodes/IfBlock.js').default | import('../../nodes/ElseBlock.js').default} node
* @param {boolean} strip_whitespace
* @param {import('./shared/Wrapper.js').default} next_sibling
*/
constructor(renderer, block, parent, node, strip_whitespace, next_sibling) {
super(renderer, block, parent, node);
const { expression } = /** @type {import('../../nodes/IfBlock.js').default} */ (node);
const is_else = !expression;
if (expression) {
this.dependencies = expression.dynamic_dependencies();
// TODO is this the right rule? or should any non-reference count?
// const should_cache = !is_reference(expression.node, null) && dependencies.length > 0;
let should_cache = false;
walk(expression.node, {
enter(node) {
if (node.type === 'CallExpression' || node.type === 'NewExpression') {
should_cache = true;
}
}
});
if (should_cache) {
this.condition = block.get_unique_name('show_if');
this.snippet = /** @type {import('estree').Node} */ (expression.manipulate(block));
} else {
this.condition = expression.manipulate(block);
}
}
add_const_tags_context(renderer, this.node.const_tags);
this.block = block.child({
comment: create_debugging_comment(node, parent.renderer.component),
name: parent.renderer.component.get_unique_name(
is_else ? 'create_else_block' : 'create_if_block'
),
type: /** @type {import('../../nodes/IfBlock.js').default} */ (node).expression
? 'if'
: 'else'
});
this.fragment = new FragmentWrapper(
renderer,
this.block,
node.children,
parent,
strip_whitespace,
next_sibling
);
this.is_dynamic = this.block.dependencies.size > 0;
if (node.const_tags.length > 0) {
this.get_ctx_name = parent.renderer.component.get_unique_name(
is_else ? 'get_else_ctx' : 'get_if_ctx'
);
}
}
}
/** @extends Wrapper<import('../../nodes/IfBlock.js').default> */
export default class IfBlockWrapper extends Wrapper {
/** @typedef {'detaching' | null} DetachingOrNull */
/** @type {IfBlockBranch[]} */
branches;
/** */
needs_update = false;
/** @type {import('estree').Identifier} */
var = { type: 'Identifier', name: 'if_block' };
/**
* @param {import('../Renderer.js').default} renderer
* @param {import('../Block.js').default} block
* @param {import('./shared/Wrapper.js').default} parent
* @param {import('../../nodes/IfBlock.js').default} node
* @param {boolean} strip_whitespace
* @param {import('./shared/Wrapper.js').default} next_sibling
*/
constructor(renderer, block, parent, node, strip_whitespace, next_sibling) {
super(renderer, block, parent, node);
this.branches = [];
/** @type {import('../Block.js').default[]} */
const blocks = [];
let is_dynamic = false;
let has_intros = false;
let has_outros = false;
/** @param {import('../../nodes/IfBlock.js').default} node */
const create_branches = (node) => {
const branch = new IfBlockBranch(renderer, block, this, node, strip_whitespace, next_sibling);
this.branches.push(branch);
blocks.push(branch.block);
block.add_dependencies(node.expression.dependencies);
if (branch.block.dependencies.size > 0) {
// the condition, or its contents, is dynamic
is_dynamic = true;
block.add_dependencies(branch.block.dependencies);
}
if (branch.dependencies && branch.dependencies.length > 0) {
// the condition itself is dynamic
this.needs_update = true;
}
if (branch.block.has_intros) has_intros = true;
if (branch.block.has_outros) has_outros = true;
if (is_else_if(node.else)) {
create_branches(
/** @type {import('../../nodes/IfBlock.js').default} */ (node.else.children[0])
);
} else if (node.else) {
const branch = new IfBlockBranch(
renderer,
block,
this,
node.else,
strip_whitespace,
next_sibling
);
this.branches.push(branch);
blocks.push(branch.block);
if (branch.block.dependencies.size > 0) {
is_dynamic = true;
block.add_dependencies(branch.block.dependencies);
}
if (branch.block.has_intros) has_intros = true;
if (branch.block.has_outros) has_outros = true;
}
};
create_branches(this.node);
blocks.forEach((block) => {
block.has_update_method = is_dynamic;
block.has_intro_method = has_intros;
block.has_outro_method = has_outros;
});
push_array(renderer.blocks, blocks);
}
/**
* @param {import('../Block.js').default} block
* @param {import('estree').Identifier} parent_node
* @param {import('estree').Identifier} parent_nodes
*/
render(block, parent_node, parent_nodes) {
const name = this.var;
const needs_anchor = this.next
? !this.next.is_dom_node()
: !parent_node || !this.parent.is_dom_node();
const anchor = needs_anchor
? block.get_unique_name(`${this.var.name}_anchor`)
: (this.next && this.next.var) || 'null';
const has_else = !this.branches[this.branches.length - 1].condition;
const if_exists_condition = has_else ? null : name;
const dynamic = this.branches[0].block.has_update_method; // can use [0] as proxy for all, since they necessarily have the same value
const has_intros = this.branches[0].block.has_intro_method;
const has_outros = this.branches[0].block.has_outro_method;
const has_transitions = has_intros || has_outros;
this.branches.forEach((branch) => {
if (branch.get_ctx_name) {
this.renderer.blocks.push(b`
function ${branch.get_ctx_name}(#ctx) {
const child_ctx = #ctx.slice();
${add_const_tags(block, branch.node.const_tags, 'child_ctx')}
return child_ctx;
}
`);
}
});
const vars = { name, anchor, if_exists_condition, has_else, has_transitions };
/** @type {DetachingOrNull} */
const detaching = parent_node && !is_head(parent_node) ? null : 'detaching';
if (this.node.else) {
this.branches.forEach((branch) => {
if (branch.snippet) block.add_variable(branch.condition);
});
if (has_outros) {
this.render_compound_with_outros(
block,
parent_node,
parent_nodes,
dynamic,
vars,
detaching
);
block.chunks.outro.push(b`@transition_out(${name});`);
} else {
this.render_compound(block, parent_node, parent_nodes, dynamic, vars, detaching);
}
} else {
this.render_simple(block, parent_node, parent_nodes, dynamic, vars, detaching);
if (has_outros) {
block.chunks.outro.push(b`@transition_out(${name});`);
}
}
if (if_exists_condition) {
block.chunks.create.push(b`if (${if_exists_condition}) ${name}.c();`);
} else {
block.chunks.create.push(b`${name}.c();`);
}
if (parent_nodes && this.renderer.options.hydratable) {
if (if_exists_condition) {
block.chunks.claim.push(b`if (${if_exists_condition}) ${name}.l(${parent_nodes});`);
} else {
block.chunks.claim.push(b`${name}.l(${parent_nodes});`);
}
}
if (has_intros || has_outros) {
block.chunks.intro.push(b`@transition_in(${name});`);
}
if (needs_anchor) {
block.add_element(
/** @type {import('estree').Identifier} */ (anchor),
x`@empty()`,
parent_nodes && x`@empty()`,
parent_node
);
}
this.branches.forEach((branch) => {
branch.fragment.render(
branch.block,
null,
/** @type {unknown} */ /** @type {import('estree').Identifier} */ (x`#nodes`)
);
});
}
/**
* @param {import('../Block.js').default} block
* @param {import('estree').Identifier} parent_node
* @param {import('estree').Identifier} _parent_nodes
* @param {boolean} dynamic
* @param {any} opts
* @param {DetachingOrNull} detaching
*/
render_compound(
block,
parent_node,
_parent_nodes,
dynamic,
{ name, anchor, has_else, if_exists_condition, has_transitions },
detaching
) {
const select_block_type = this.renderer.component.get_unique_name('select_block_type');
const current_block_type = block.get_unique_name('current_block_type');
const need_select_block_ctx = this.branches.some((branch) => branch.get_ctx_name);
const select_block_ctx = need_select_block_ctx
? block.get_unique_name('select_block_ctx')
: null;
const if_ctx = select_block_ctx ? x`${select_block_ctx}(#ctx, ${current_block_type})` : x`#ctx`;
const get_block = has_else
? x`${current_block_type}(${if_ctx})`
: x`${current_block_type} && ${current_block_type}(${if_ctx})`;
if (this.needs_update) {
block.chunks.init.push(b`
function ${select_block_type}(#ctx, #dirty) {
${this.branches.map(({ dependencies, condition, snippet }) => {
return b`${
snippet && dependencies.length > 0
? b`if (${block.renderer.dirty(dependencies)}) ${condition} = null;`
: null
}`;
})}
${this.branches.map(({ condition, snippet, block }) =>
condition
? b`
${snippet && b`if (${condition} == null) ${condition} = !!${snippet}`}
if (${condition}) return ${block.name};`
: b`return ${block.name};`
)}
}
`);
} else {
block.chunks.init.push(b`
function ${select_block_type}(#ctx, #dirty) {
${this.branches.map(({ condition, snippet, block }) =>
condition
? b`if (${snippet || condition}) return ${block.name};`
: b`return ${block.name};`
)}
}
`);
}
if (need_select_block_ctx) {
// if all branches needs create a context
if (this.branches.every((branch) => branch.get_ctx_name)) {
block.chunks.init.push(b`
function ${select_block_ctx}(#ctx, #type) {
${this.branches
.map(({ condition, get_ctx_name, block }) => {
return condition
? b`if (#type === ${block.name}) return ${get_ctx_name}(#ctx);`
: b`return ${get_ctx_name}(#ctx);`;
})
.filter(Boolean)}
}
`);
} else {
// when not all branches need to create a new context,
// this code is simpler
block.chunks.init.push(b`
function ${select_block_ctx}(#ctx, #type) {
${this.branches
.map(({ get_ctx_name, block }) => {
return get_ctx_name
? b`if (#type === ${block.name}) return ${get_ctx_name}(#ctx);`
: null;
})
.filter(Boolean)}
return #ctx;
}
`);
}
}
block.chunks.init.push(b`
let ${current_block_type} = ${select_block_type}(#ctx, ${this.renderer.get_initial_dirty()});
let ${name} = ${get_block};
`);
const initial_mount_node = parent_node || '#target';
const anchor_node = parent_node ? 'null' : '#anchor';
if (if_exists_condition) {
block.chunks.mount.push(
b`if (${if_exists_condition}) ${name}.m(${initial_mount_node}, ${anchor_node});`
);
} else {
block.chunks.mount.push(b`${name}.m(${initial_mount_node}, ${anchor_node});`);
}
if (this.needs_update) {
const update_mount_node = this.get_update_mount_node(anchor);
const change_block = b`
${if_exists_condition ? b`if (${if_exists_condition}) ${name}.d(1)` : b`${name}.d(1)`};
${name} = ${get_block};
if (${name}) {
${name}.c();
${has_transitions && b`@transition_in(${name}, 1);`}
${name}.m(${update_mount_node}, ${anchor});
}
`;
if (dynamic) {
block.chunks.update.push(b`
if (${current_block_type} === (${current_block_type} = ${select_block_type}(#ctx, #dirty)) && ${name}) {
${name}.p(${if_ctx}, #dirty);
} else {
${change_block}
}
`);
} else {
block.chunks.update.push(b`
if (${current_block_type} !== (${current_block_type} = ${select_block_type}(#ctx, #dirty))) {
${change_block}
}
`);
}
} else if (dynamic) {
if (if_exists_condition) {
block.chunks.update.push(b`if (${if_exists_condition}) ${name}.p(${if_ctx}, #dirty);`);
} else {
block.chunks.update.push(b`${name}.p(${if_ctx}, #dirty);`);
}
}
if (if_exists_condition) {
block.chunks.destroy.push(b`
if (${if_exists_condition}) {
${name}.d(${detaching});
}
`);
} else {
block.chunks.destroy.push(b`
${name}.d(${detaching});
`);
}
}
// if any of the siblings have outros, we need to keep references to the blocks
// (TODO does this only apply to bidi transitions?)
/**
* @param {import('../Block.js').default} block
* @param {import('estree').Identifier} parent_node
* @param {import('estree').Identifier} _parent_nodes
* @param {boolean} dynamic
* @param {any} opts
* @param {DetachingOrNull} detaching
*/
render_compound_with_outros(
block,
parent_node,
_parent_nodes,
dynamic,
{ name, anchor, has_else, has_transitions, if_exists_condition },
detaching
) {
const select_block_type = this.renderer.component.get_unique_name('select_block_type');
const current_block_type_index = block.get_unique_name('current_block_type_index');
const previous_block_index = block.get_unique_name('previous_block_index');
const if_block_creators = block.get_unique_name('if_block_creators');
const if_blocks = block.get_unique_name('if_blocks');
const need_select_block_ctx = this.branches.some((branch) => branch.get_ctx_name);
const select_block_ctx = need_select_block_ctx
? block.get_unique_name('select_block_ctx')
: null;
const if_ctx = select_block_ctx
? x`${select_block_ctx}(#ctx, ${current_block_type_index})`
: x`#ctx`;
const if_current_block_type_index = has_else
? (nodes) => nodes
: (nodes) => b`if (~${current_block_type_index}) { ${nodes} }`;
block.add_variable(current_block_type_index);
block.add_variable(name);
block.chunks.init.push(b`
const ${if_block_creators} = [
${this.branches.map((branch) => branch.block.name)}
];
const ${if_blocks} = [];
${
this.needs_update
? b`
function ${select_block_type}(#ctx, #dirty) {
${this.branches.map(({ dependencies, condition, snippet }) => {
return b`${
snippet && dependencies.length > 0
? b`if (${block.renderer.dirty(dependencies)}) ${condition} = null;`
: null
}`;
})}
${this.branches.map(({ condition, snippet }, i) =>
condition
? b`
${snippet && b`if (${condition} == null) ${condition} = !!${snippet}`}
if (${condition}) return ${i};`
: b`return ${i};`
)}
${!has_else && b`return -1;`}
}
`
: b`
function ${select_block_type}(#ctx, #dirty) {
${this.branches.map(({ condition, snippet }, i) =>
condition ? b`if (${snippet || condition}) return ${i};` : b`return ${i};`
)}
${!has_else && b`return -1;`}
}
`
}
`);
if (need_select_block_ctx) {
// if all branches needs create a context
if (this.branches.every((branch) => branch.get_ctx_name)) {
block.chunks.init.push(b`
function ${select_block_ctx}(#ctx, #index) {
${this.branches
.map(({ condition, get_ctx_name }, i) => {
return condition
? b`if (#index === ${i}) return ${get_ctx_name}(#ctx);`
: b`return ${get_ctx_name}(#ctx);`;
})
.filter(Boolean)}
}
`);
} else {
// when not all branches need to create a new context,
// this code is simpler
block.chunks.init.push(b`
function ${select_block_ctx}(#ctx, #index) {
${this.branches
.map(({ get_ctx_name }, i) => {
return get_ctx_name ? b`if (#index === ${i}) return ${get_ctx_name}(#ctx);` : null;
})
.filter(Boolean)}
return #ctx;
}
`);
}
}
if (has_else) {
block.chunks.init.push(b`
${current_block_type_index} = ${select_block_type}(#ctx, ${this.renderer.get_initial_dirty()});
${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](${if_ctx});
`);
} else {
block.chunks.init.push(b`
if (~(${current_block_type_index} = ${select_block_type}(#ctx, ${this.renderer.get_initial_dirty()}))) {
${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](${if_ctx});
}
`);
}
const initial_mount_node = parent_node || '#target';
const anchor_node = parent_node ? 'null' : '#anchor';
block.chunks.mount.push(
if_current_block_type_index(
b`${if_blocks}[${current_block_type_index}].m(${initial_mount_node}, ${anchor_node});`
)
);
if (this.needs_update) {
const update_mount_node = this.get_update_mount_node(anchor);
const destroy_old_block = b`
@group_outros();
@transition_out(${if_blocks}[${previous_block_index}], 1, 1, () => {
${if_blocks}[${previous_block_index}] = null;
});
@check_outros();
`;
const create_new_block = b`
${name} = ${if_blocks}[${current_block_type_index}];
if (!${name}) {
${name} = ${if_blocks}[${current_block_type_index}] = ${if_block_creators}[${current_block_type_index}](${if_ctx});
${name}.c();
} else {
${dynamic && b`${name}.p(${if_ctx}, #dirty);`}
}
${has_transitions && b`@transition_in(${name}, 1);`}
${name}.m(${update_mount_node}, ${anchor});
`;
const change_block = has_else
? b`
${destroy_old_block}
${create_new_block}
`
: b`
if (${name}) {
${destroy_old_block}
}
if (~${current_block_type_index}) {
${create_new_block}
} else {
${name} = null;
}
`;
block.chunks.update.push(b`
let ${previous_block_index} = ${current_block_type_index};
${current_block_type_index} = ${select_block_type}(#ctx, #dirty);
`);
if (dynamic) {
block.chunks.update.push(b`
if (${current_block_type_index} === ${previous_block_index}) {
${if_current_block_type_index(b`${if_blocks}[${current_block_type_index}].p(${if_ctx}, #dirty);`)}
} else {
${change_block}
}
`);
} else {
block.chunks.update.push(b`
if (${current_block_type_index} !== ${previous_block_index}) {
${change_block}
}
`);
}
} else if (dynamic) {
if (if_exists_condition) {
block.chunks.update.push(b`if (${if_exists_condition}) ${name}.p(${if_ctx}, #dirty);`);
} else {
block.chunks.update.push(b`${name}.p(${if_ctx}, #dirty);`);
}
}
block.chunks.destroy.push(
if_current_block_type_index(b`${if_blocks}[${current_block_type_index}].d(${detaching});`)
);
}
/**
* @param {import('../Block.js').default} block
* @param {import('estree').Identifier} parent_node
* @param {import('estree').Identifier} _parent_nodes
* @param {boolean} dynamic
* @param {any} opts
* @param {DetachingOrNull} detaching
*/
render_simple(
block,
parent_node,
_parent_nodes,
dynamic,
{ name, anchor, if_exists_condition, has_transitions },
detaching
) {
const branch = this.branches[0];
const if_ctx = branch.get_ctx_name ? x`${branch.get_ctx_name}(#ctx)` : x`#ctx`;
if (branch.snippet) block.add_variable(branch.condition, branch.snippet);
block.chunks.init.push(b`
let ${name} = ${branch.condition} && ${branch.block.name}(${if_ctx});
`);
const initial_mount_node = parent_node || '#target';
const anchor_node = parent_node ? 'null' : '#anchor';
block.chunks.mount.push(b`if (${name}) ${name}.m(${initial_mount_node}, ${anchor_node});`);
if (branch.dependencies.length > 0) {
const update_mount_node = this.get_update_mount_node(anchor);
const enter = b`
if (${name}) {
${dynamic && b`${name}.p(${if_ctx}, #dirty);`}
${
has_transitions &&
b`if (${block.renderer.dirty(branch.dependencies)}) {
@transition_in(${name}, 1);
}`
}
} else {
${name} = ${branch.block.name}(${if_ctx});
${name}.c();
${has_transitions && b`@transition_in(${name}, 1);`}
${name}.m(${update_mount_node}, ${anchor});
}
`;
if (branch.snippet) {
block.chunks.update.push(
b`if (${block.renderer.dirty(branch.dependencies)}) ${branch.condition} = ${
branch.snippet
}`
);
}
// no `p()` here — we don't want to update outroing nodes,
// as that will typically result in glitching
if (branch.block.has_outro_method) {
block.chunks.update.push(b`
if (${branch.condition}) {
${enter}
} else if (${name}) {
@group_outros();
@transition_out(${name}, 1, 1, () => {
${name} = null;
});
@check_outros();
}
`);
} else {
block.chunks.update.push(b`
if (${branch.condition}) {
${enter}
} else if (${name}) {
${name}.d(1);
${name} = null;
}
`);
}
} else if (dynamic) {
block.chunks.update.push(b`
if (${branch.condition}) ${name}.p(${if_ctx}, #dirty);
`);
}
if (if_exists_condition) {
block.chunks.destroy.push(b`
if (${if_exists_condition}) ${name}.d(${detaching});
`);
} else {
block.chunks.destroy.push(b`
${name}.d(${detaching});
`);
}
}
}