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svelte/compiler/generate/index.js

577 lines
16 KiB

import MagicString, { Bundle } from 'magic-string';
import { walk } from 'estree-walker';
import deindent from './utils/deindent.js';
import isReference from './utils/isReference.js';
import counter from './utils/counter.js';
import flattenReference from './utils/flattenReference.js';
import getIntro from './utils/getIntro.js';
import getOutro from './utils/getOutro.js';
import visitors from './visitors/index.js';
import processCss from './css/process.js';
export default function generate ( parsed, source, options ) {
const format = options.format || 'es';
const renderers = [];
const generator = {
addElement ( name, renderStatement, needsIdentifier = false ) {
const isToplevel = generator.current.localElementDepth === 0;
if ( needsIdentifier || isToplevel ) {
generator.current.initStatements.push( deindent`
var ${name} = ${renderStatement};
` );
generator.createMountStatement( name );
} else {
generator.current.initStatements.push( deindent`
${generator.current.target}.appendChild( ${renderStatement} );
` );
}
if ( isToplevel ) {
generator.current.detachStatements.push( deindent`
${name}.parentNode.removeChild( ${name} );
` );
}
},
createMountStatement ( name ) {
if ( generator.current.target === 'target' ) {
generator.current.mountStatements.push( deindent`
target.insertBefore( ${name}, anchor );
` );
} else {
generator.current.initStatements.push( deindent`
${generator.current.target}.appendChild( ${name} );
` );
}
},
createAnchor ( _name, description = '' ) {
const name = `${_name}_anchor`;
const statement = `document.createComment( ${JSON.stringify( description )} )`;
generator.addElement( name, statement, true );
return name;
},
addRenderer ( fragment ) {
if ( fragment.autofocus ) {
fragment.initStatements.push( `${fragment.autofocus}.focus();` );
}
renderers.push( deindent`
function ${fragment.name} ( ${fragment.params}, component ) {
${fragment.initStatements.join( '\n\n' )}
return {
mount: function ( target, anchor ) {
${fragment.mountStatements.join( '\n\n' )}
},
update: function ( changed, ${fragment.params} ) {
${fragment.updateStatements.join( '\n\n' )}
},
teardown: function ( detach ) {
${fragment.teardownStatements.join( '\n\n' )}
if ( detach ) {
${fragment.detachStatements.join( '\n\n' )}
}
}
};
}
` );
},
addSourcemapLocations ( node ) {
walk( node, {
enter ( node ) {
generator.code.addSourcemapLocation( node.start );
generator.code.addSourcemapLocation( node.end );
}
});
},
code: new MagicString( source ),
components: {},
contextualise ( expression, isEventHandler ) {
const usedContexts = [];
const dependencies = [];
const { contextDependencies, contexts, indexes } = generator.current;
walk( expression, {
enter ( node, parent ) {
if ( isReference( node, parent ) ) {
const { name } = flattenReference( node );
if ( parent && parent.type === 'CallExpression' && node === parent.callee ) {
if ( generator.helpers[ name ] ) generator.code.prependRight( node.start, `template.helpers.` );
return;
}
if ( name === 'event' && isEventHandler ) {
return;
}
if ( contexts[ name ] ) {
dependencies.push( ...contextDependencies[ name ] );
if ( !~usedContexts.indexOf( name ) ) usedContexts.push( name );
} else if ( indexes[ name ] ) {
const context = indexes[ name ];
if ( !~usedContexts.indexOf( context ) ) usedContexts.push( context );
} else {
dependencies.push( name );
generator.code.prependRight( node.start, `root.` );
if ( !~usedContexts.indexOf( 'root' ) ) usedContexts.push( 'root' );
}
this.skip();
}
}
});
return {
dependencies,
contexts: usedContexts,
snippet: `[✂${expression.start}-${expression.end}✂]`,
string: generator.code.slice( expression.start, expression.end )
};
},
// TODO use getName instead of counters
counters: {
if: 0,
each: 0
},
events: {},
getName: counter(),
cssId: parsed.css ? `svelte-${parsed.hash}` : '',
helpers: {},
pop () {
const tail = generator.current;
generator.current = tail.parent;
return tail;
},
push ( fragment ) {
const newFragment = Object.assign( {}, generator.current, fragment, {
parent: generator.current
});
generator.current = newFragment;
},
usesRefs: false,
source,
visit ( node ) {
const visitor = visitors[ node.type ];
if ( !visitor ) throw new Error( `Not implemented: ${node.type}` );
if ( visitor.enter ) visitor.enter( generator, node );
if ( node.children ) {
node.children.forEach( child => {
generator.visit( child );
});
}
if ( visitor.leave ) visitor.leave( generator, node );
}
};
const templateProperties = {};
const imports = [];
if ( parsed.js ) {
generator.addSourcemapLocations( parsed.js.content );
// imports need to be hoisted out of the IIFE
for ( let i = 0; i < parsed.js.content.body.length; i += 1 ) {
const node = parsed.js.content.body[i];
if ( node.type === 'ImportDeclaration' ) {
let a = node.start;
let b = node.end;
while ( /[ \t]/.test( source[ a - 1 ] ) ) a -= 1;
while ( source[b] === '\n' ) b += 1;
//imports.push( source.slice( a, b ).replace( /^\s/, '' ) );
imports.push( node );
generator.code.remove( a, b );
}
}
const defaultExport = parsed.js.content.body.find( node => node.type === 'ExportDefaultDeclaration' );
if ( defaultExport ) {
const finalNode = parsed.js.content.body[ parsed.js.content.body.length - 1 ];
if ( defaultExport === finalNode ) {
// export is last property, we can just return it
generator.code.overwrite( defaultExport.start, defaultExport.declaration.start, `return ` );
} else {
// TODO ensure `template` isn't already declared
generator.code.overwrite( defaultExport.start, defaultExport.declaration.start, `var template = ` );
let i = defaultExport.start;
while ( /\s/.test( source[ i - 1 ] ) ) i--;
const indentation = source.slice( i, defaultExport.start );
generator.code.appendLeft( finalNode.end, `\n\n${indentation}return template;` );
}
defaultExport.declaration.properties.forEach( prop => {
templateProperties[ prop.key.name ] = prop.value;
});
generator.code.prependRight( parsed.js.content.start, 'var template = (function () {' );
} else {
generator.code.prependRight( parsed.js.content.start, '(function () {' );
}
generator.code.appendLeft( parsed.js.content.end, '}());' );
[ 'helpers', 'events', 'components' ].forEach( key => {
if ( templateProperties[ key ] ) {
templateProperties[ key ].properties.forEach( prop => {
generator[ key ][ prop.key.name ] = prop.value;
});
}
});
}
generator.push({
useAnchor: false,
name: 'renderMainFragment',
namespace: null,
target: 'target',
elementDepth: 0,
localElementDepth: 0,
initStatements: [],
mountStatements: [],
updateStatements: [],
detachStatements: [],
teardownStatements: [],
contexts: {},
indexes: {},
params: 'root',
indexNames: {},
listNames: {},
counter: counter()
});
parsed.html.children.forEach( generator.visit );
generator.addRenderer( generator.pop() );
const topLevelStatements = [];
const setStatements = [ deindent`
var oldState = state;
state = Object.assign( {}, oldState, newState );
` ];
if ( templateProperties.computed ) {
const statements = [];
const dependencies = new Map();
templateProperties.computed.properties.forEach( prop => {
const key = prop.key.name;
const value = prop.value;
const deps = value.params.map( param => param.name );
dependencies.set( key, deps );
});
const visited = new Set();
function visit ( key ) {
if ( !dependencies.has( key ) ) return; // not a computation
if ( visited.has( key ) ) return;
visited.add( key );
const deps = dependencies.get( key );
deps.forEach( visit );
statements.push( deindent`
if ( ${deps.map( dep => `( '${dep}' in newState && typeof state.${dep} === 'object' || state.${dep} !== oldState.${dep} )` ).join( ' || ' )} ) {
state.${key} = newState.${key} = template.computed.${key}( ${deps.map( dep => `state.${dep}` ).join( ', ' )} );
}
` );
}
templateProperties.computed.properties.forEach( prop => visit( prop.key.name ) );
topLevelStatements.push( deindent`
function applyComputations ( state, newState, oldState ) {
${statements.join( '\n\n' )}
}
` );
setStatements.push( `applyComputations( state, newState, oldState )` );
}
setStatements.push( deindent`
dispatchObservers( observers.immediate, newState, oldState );
if ( mainFragment ) mainFragment.update( newState, state );
dispatchObservers( observers.deferred, newState, oldState );
` );
const importBlock = imports
.map( ( declaration, i ) => {
if ( format === 'es' ) {
return source.slice( declaration.start, declaration.end );
}
const defaultImport = declaration.specifiers.find( x => x.type === 'ImportDefaultSpecifier' || x.type === 'ImportSpecifier' && x.imported.name === 'default' );
const namespaceImport = declaration.specifiers.find( x => x.type === 'ImportNamespaceSpecifier' );
const namedImports = declaration.specifiers.filter( x => x.type === 'ImportSpecifier' && x.imported.name !== 'default' );
const name = ( defaultImport || namespaceImport ) ? ( defaultImport || namespaceImport ).local.name : `__import${i}`;
declaration.name = name; // hacky but makes life a bit easier later
const statements = namedImports.map( specifier => {
return `var ${specifier.local.name} = ${name}.${specifier.imported.name}`;
});
if ( defaultImport ) {
statements.push( `${name} = ( ${name} && ${name}.__esModule ) ? ${name}['default'] : ${name};` );
}
return statements.join( '\n' );
})
.filter( Boolean )
.join( '\n' );
if ( parsed.js ) {
if ( imports.length ) {
topLevelStatements.push( importBlock );
}
topLevelStatements.push( `[✂${parsed.js.content.start}-${parsed.js.content.end}✂]` );
}
if ( parsed.css ) {
topLevelStatements.push( processCss( parsed ) );
}
topLevelStatements.push( ...renderers.reverse() );
const constructorName = options.name || 'SvelteComponent';
const initStatements = [];
if ( parsed.css ) {
initStatements.push( `if ( !addedCss ) addCss();` );
}
if ( generator.hasComponents ) {
initStatements.push( deindent`
this.__renderHooks = [];
` );
}
if ( generator.hasComplexBindings ) {
initStatements.push( deindent`
this.__bindings = [];
var mainFragment = renderMainFragment( state, this );
if ( options.target ) this.mount( options.target );
while ( this.__bindings.length ) this.__bindings.pop()();
` );
setStatements.push( `while ( this.__bindings.length ) this.__bindings.pop()();` );
} else {
initStatements.push( deindent`
var mainFragment = renderMainFragment( state, this );
if ( options.target ) this.mount( options.target );
` );
}
if ( generator.hasComponents ) {
const statement = deindent`
while ( this.__renderHooks.length ) {
var hook = this.__renderHooks.pop();
hook.fn.call( hook.context );
}
`;
initStatements.push( statement );
setStatements.push( statement );
}
if ( templateProperties.onrender ) {
initStatements.push( deindent`
if ( options.root ) {
options.root.__renderHooks.push({ fn: template.onrender, context: this });
} else {
template.onrender.call( this );
}
` );
}
const initialState = templateProperties.data ? `Object.assign( template.data(), options.data )` : `options.data || {}`;
topLevelStatements.push( deindent`
function ${constructorName} ( options ) {
var component = this;${generator.usesRefs ? `\nthis.refs = {}` : ``}
var state = ${initialState};${templateProperties.computed ? `\napplyComputations( state, state, {} );` : ``}
var observers = {
immediate: Object.create( null ),
deferred: Object.create( null )
};
var callbacks = Object.create( null );
function dispatchObservers ( group, newState, oldState ) {
for ( var key in group ) {
if ( !( key in newState ) ) continue;
var newValue = newState[ key ];
var oldValue = oldState[ key ];
if ( newValue === oldValue && typeof newValue !== 'object' ) continue;
var callbacks = group[ key ];
if ( !callbacks ) continue;
for ( var i = 0; i < callbacks.length; i += 1 ) {
var callback = callbacks[i];
if ( callback.__calling ) continue;
callback.__calling = true;
callback.call( component, newValue, oldValue );
callback.__calling = false;
}
}
}
this.fire = function fire ( eventName, data ) {
var handlers = eventName in callbacks && callbacks[ eventName ].slice();
if ( !handlers ) return;
for ( var i = 0; i < handlers.length; i += 1 ) {
handlers[i].call( this, data );
}
};
this.get = function get ( key ) {
return key ? state[ key ] : state;
};
this.set = function set ( newState ) {
${setStatements.join( '\n\n' )}
};
this.mount = function mount ( target, anchor ) {
mainFragment.mount( target, anchor );
}
this.observe = function ( key, callback, options ) {
var group = ( options && options.defer ) ? observers.deferred : observers.immediate;
( group[ key ] || ( group[ key ] = [] ) ).push( callback );
if ( !options || options.init !== false ) {
callback.__calling = true;
callback.call( component, state[ key ] );
callback.__calling = false;
}
return {
cancel: function () {
var index = group[ key ].indexOf( callback );
if ( ~index ) group[ key ].splice( index, 1 );
}
};
};
this.on = function on ( eventName, handler ) {
var handlers = callbacks[ eventName ] || ( callbacks[ eventName ] = [] );
handlers.push( handler );
return {
cancel: function () {
var index = handlers.indexOf( handler );
if ( ~index ) handlers.splice( index, 1 );
}
};
};
this.teardown = function teardown ( detach ) {
this.fire( 'teardown' );${templateProperties.onteardown ? `\ntemplate.onteardown.call( this );` : ``}
mainFragment.teardown( detach !== false );
mainFragment = null;
state = {};
};
this.root = options.root;
this.yield = options.yield;
${initStatements.join( '\n\n' )}
}
` );
if ( templateProperties.methods ) {
topLevelStatements.push( `${constructorName}.prototype = template.methods;` );
}
const result = topLevelStatements.join( '\n\n' );
const pattern = /\[✂(\d+)-(\d+)$/;
const parts = result.split( '✂]' );
const finalChunk = parts.pop();
const compiled = new Bundle({ separator: '' });
function addString ( str ) {
compiled.addSource({
content: new MagicString( str )
});
}
const intro = getIntro( format, options, imports );
if ( intro ) addString( intro );
// a filename is necessary for sourcemap generation
const filename = options.filename || 'SvelteComponent.html';
parts.forEach( str => {
const chunk = str.replace( pattern, '' );
if ( chunk ) addString( chunk );
const match = pattern.exec( str );
const snippet = generator.code.snip( +match[1], +match[2] );
compiled.addSource({
filename,
content: snippet
});
});
addString( finalChunk );
addString( '\n\n' + getOutro( format, constructorName, options, imports ) );
return {
code: compiled.toString(),
map: compiled.generateMap({ includeContent: true })
};
}