svelte/src/compiler/compile/nodes/EachBlock.ts

77 lines
2.2 KiB

import ElseBlock from './ElseBlock';
import Expression from './shared/Expression';
import map_children from './shared/map_children';
import TemplateScope from './shared/TemplateScope';
import AbstractBlock from './shared/AbstractBlock';
import Element from './Element';
import { Context, unpack_destructuring } from './shared/Context';
import { Node } from 'estree';
import Component from '../Component';
import { TemplateNode } from '../../interfaces';
import compiler_errors from '../compiler_errors';
export default class EachBlock extends AbstractBlock {
type: 'EachBlock';
expression: Expression;
context_node: Node;
iterations: string;
index: string;
context: string;
key: Expression;
scope: TemplateScope;
contexts: Context[];
has_animation: boolean;
has_binding = false;
has_index_binding = false;
else?: ElseBlock;
constructor(component: Component, parent: Node, scope: TemplateScope, info: TemplateNode) {
super(component, parent, scope, info);
this.expression = new Expression(component, this, scope, info.expression);
this.context = info.context.name || 'each'; // TODO this is used to facilitate binding; currently fails with destructuring
this.context_node = info.context;
this.index = info.index;
this.scope = scope.child();
this.contexts = [];
unpack_destructuring(this.contexts, info.context);
this.contexts.forEach(context => {
this.scope.add(context.key.name, this.expression.dependencies, this);
});
if (this.index) {
// index can only change if this is a keyed each block
const dependencies = info.key ? this.expression.dependencies : new Set([]);
this.scope.add(this.index, dependencies, this);
}
this.key = info.key
? new Expression(component, this, this.scope, info.key)
: null;
this.has_animation = false;
this.children = map_children(component, this, this.scope, info.children);
if (this.has_animation) {
if (this.children.length !== 1) {
const child = this.children.find(child => !!(child as Element).animation);
component.error((child as Element).animation, compiler_errors.invalid_animation_sole);
return;
}
}
this.warn_if_empty_block();
this.else = info.else
? new ElseBlock(component, this, this.scope, info.else)
: null;
}
}