svelte/src/server-side-rendering/compile.js

436 lines
11 KiB

import { walk } from 'estree-walker';
import deindent from '../utils/deindent.js';
import isReference from '../utils/isReference.js';
import flattenReference from '../utils/flattenReference.js';
import MagicString, { Bundle } from 'magic-string';
import processCss from '../generate/css/process.js';
const voidElementNames = /^(?:area|base|br|col|command|doctype|embed|hr|img|input|keygen|link|meta|param|source|track|wbr)$/i;
export default function compile ( parsed, source, { filename }) {
const code = new MagicString( source );
const templateProperties = {};
const components = {};
const helpers = {};
const imports = [];
if ( parsed.js ) {
walk( parsed.js.content, {
enter ( node ) {
code.addSourcemapLocation( node.start );
code.addSourcemapLocation( node.end );
}
});
// imports need to be hoisted out of the IIFE
for ( let i = 0; i < parsed.js.content.body.length; i += 1 ) {
const node = parsed.js.content.body[i];
if ( node.type === 'ImportDeclaration' ) {
let a = node.start;
let b = node.end;
while ( /[ \t]/.test( source[ a - 1 ] ) ) a -= 1;
while ( source[b] === '\n' ) b += 1;
//imports.push( source.slice( a, b ).replace( /^\s/, '' ) );
imports.push( node );
code.remove( a, b );
}
}
const defaultExport = parsed.js.content.body.find( node => node.type === 'ExportDefaultDeclaration' );
if ( defaultExport ) {
const finalNode = parsed.js.content.body[ parsed.js.content.body.length - 1 ];
if ( defaultExport === finalNode ) {
// export is last property, we can just return it
code.overwrite( defaultExport.start, defaultExport.declaration.start, `return ` );
} else {
// TODO ensure `template` isn't already declared
code.overwrite( defaultExport.start, defaultExport.declaration.start, `var template = ` );
let i = defaultExport.start;
while ( /\s/.test( source[ i - 1 ] ) ) i--;
const indentation = source.slice( i, defaultExport.start );
code.appendLeft( finalNode.end, `\n\n${indentation}return template;` );
}
defaultExport.declaration.properties.forEach( prop => {
templateProperties[ prop.key.name ] = prop.value;
});
code.prependRight( parsed.js.content.start, 'var template = (function () {' );
} else {
code.prependRight( parsed.js.content.start, '(function () {' );
}
code.appendLeft( parsed.js.content.end, '}());' );
if ( templateProperties.helpers ) {
templateProperties.helpers.properties.forEach( prop => {
helpers[ prop.key.name ] = prop.value;
});
}
if ( templateProperties.components ) {
templateProperties.components.properties.forEach( prop => {
components[ prop.key.name ] = prop.value;
});
}
}
let scope = new Set();
const scopes = [ scope ];
function contextualise ( expression ) {
walk( expression, {
enter ( node, parent ) {
if ( isReference( node, parent ) ) {
const { name } = flattenReference( node );
if ( parent && parent.type === 'CallExpression' && node === parent.callee && helpers[ name ] ) {
code.prependRight( node.start, `template.helpers.` );
return;
}
if ( !scope.has( name ) ) {
code.prependRight( node.start, `data.` );
}
this.skip();
}
}
});
return {
snippet: `[✂${expression.start}-${expression.end}✂]`,
string: code.slice( expression.start, expression.end )
};
}
let elementDepth = 0;
const stringifiers = {
Comment () {
return '';
},
Component ( node ) {
const props = node.attributes.map( attribute => {
let value;
if ( attribute.value === true ) {
value = `true`;
} else if ( attribute.value.length === 0 ) {
value = `''`;
} else if ( attribute.value.length === 1 ) {
const chunk = attribute.value[0];
if ( chunk.type === 'Text' ) {
value = isNaN( parseFloat( chunk.data ) ) ? JSON.stringify( chunk.data ) : chunk.data;
} else {
const { snippet } = contextualise( chunk.expression );
value = snippet;
}
} else {
value = '`' + attribute.value.map( stringify ).join( '' ) + '`';
}
return `${attribute.name}: ${value}`;
}).join( ', ' );
let params = `{${props}}`;
if ( node.children.length ) {
params += `, { yield: () => \`${node.children.map( stringify ).join( '' )}\` }`;
}
return `\${template.components.${node.name}.render(${params})}`;
},
EachBlock ( node ) {
const { snippet } = contextualise( node.expression );
scope = new Set();
scope.add( node.context );
if ( node.index ) scope.add( node.index );
scopes.push( scope );
const block = `\${ ${snippet}.map( ${ node.index ? `( ${node.context}, ${node.index} )` : node.context} => \`${ node.children.map( stringify ).join( '' )}\` ).join( '' )}`;
scopes.pop();
scope = scopes[ scopes.length - 1 ];
return block;
},
Element ( node ) {
if ( node.name in components ) {
return stringifiers.Component( node );
}
let element = `<${node.name}`;
node.attributes.forEach( attribute => {
if ( attribute.type !== 'Attribute' ) return;
let str = ` ${attribute.name}`;
if ( attribute.value !== true ) {
str += `="` + attribute.value.map( chunk => {
if ( chunk.type === 'Text' ) {
return chunk.data;
}
const { snippet } = contextualise( chunk.expression );
return '${' + snippet + '}';
}).join( '' ) + `"`;
}
element += str;
});
if ( parsed.css && elementDepth === 0 ) {
element += ` svelte-${parsed.hash}`;
}
if ( voidElementNames.test( node.name ) ) {
element += '>';
} else {
elementDepth += 1;
element += '>' + node.children.map( stringify ).join( '' ) + `</${node.name}>`;
elementDepth -= 1;
}
return element;
},
IfBlock ( node ) {
const { snippet } = contextualise( node.expression ); // TODO use snippet, for sourcemap support
const consequent = node.children.map( stringify ).join( '' );
const alternate = node.else ? node.else.children.map( stringify ).join( '' ) : '';
return '${ ' + snippet + ' ? `' + consequent + '` : `' + alternate + '` }';
},
MustacheTag ( node ) {
const { snippet } = contextualise( node.expression ); // TODO use snippet, for sourcemap support
return '${__escape( String( ' + snippet + ') )}';
},
RawMustacheTag ( node ) {
const { snippet } = contextualise( node.expression ); // TODO use snippet, for sourcemap support
return '${' + snippet + '}';
},
Text ( node ) {
return node.data.replace( /\${/g, '\\${' );
},
YieldTag () {
return `\${options.yield()}`;
}
};
function stringify ( node ) {
const stringifier = stringifiers[ node.type ];
if ( !stringifier ) {
throw new Error( `Not implemented: ${node.type}` );
}
return stringifier( node );
}
function createBlock ( node ) {
const str = stringify( node );
if ( str.slice( 0, 2 ) === '${' ) return str.slice( 2, -1 );
return '`' + str + '`';
}
const blocks = parsed.html.children.map( node => {
return deindent`
rendered += ${createBlock( node )};
`;
});
const topLevelStatements = [];
const importBlock = imports
.map( ( declaration, i ) => {
const defaultImport = declaration.specifiers.find( x => x.type === 'ImportDefaultSpecifier' || x.type === 'ImportSpecifier' && x.imported.name === 'default' );
const namespaceImport = declaration.specifiers.find( x => x.type === 'ImportNamespaceSpecifier' );
const namedImports = declaration.specifiers.filter( x => x.type === 'ImportSpecifier' && x.imported.name !== 'default' );
const name = ( defaultImport || namespaceImport ) ? ( defaultImport || namespaceImport ).local.name : `__import${i}`;
const statements = [
`var ${name} = require( '${declaration.source.value}' );`
];
namedImports.forEach( specifier => {
statements.push( `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}-${parsed.js.content.end}✂]` );
}
const renderStatements = [
templateProperties.data ? `data = Object.assign( template.data(), data || {} );` : `data = data || {};`
];
if ( templateProperties.computed ) {
const statements = [];
const dependencies = new Map();
templateProperties.computed.properties.forEach( prop => {
const key = prop.key.name;
const value = prop.value;
const deps = value.params.map( param => param.name );
dependencies.set( key, deps );
});
const visited = new Set();
function visit ( key ) {
if ( !dependencies.has( key ) ) return; // not a computation
if ( visited.has( key ) ) return;
visited.add( key );
const deps = dependencies.get( key );
deps.forEach( visit );
statements.push( deindent`
data.${key} = template.computed.${key}( ${deps.map( dep => `data.${dep}` ).join( ', ' )} );
` );
}
templateProperties.computed.properties.forEach( prop => visit( prop.key.name ) );
renderStatements.push( statements.join( '\n' ) );
}
renderStatements.push(
`var rendered = '';`,
blocks.join( '\n\n' ),
`return rendered;`
);
const renderCssStatements = [
`var components = [];`
];
if ( parsed.css ) {
renderCssStatements.push( deindent`
components.push({
filename: exports.filename,
css: ${JSON.stringify( processCss( parsed ) )},
map: null // TODO
});
` );
}
if ( templateProperties.components ) {
renderCssStatements.push( deindent`
var seen = {};
function addComponent ( component ) {
var result = component.renderCss();
result.components.forEach( x => {
if ( seen[ x.filename ] ) return;
seen[ x.filename ] = true;
components.push( x );
});
}
` );
renderCssStatements.push( templateProperties.components.properties.map( prop => `addComponent( template.components.${prop.key.name} );` ).join( '\n' ) );
}
renderCssStatements.push( deindent`
return {
css: components.map( x => x.css ).join( '\\n' ),
map: null,
components
};
` );
topLevelStatements.push( deindent`
exports.filename = ${JSON.stringify( filename )};
exports.render = function ( data, options ) {
${renderStatements.join( '\n\n' )}
};
exports.renderCss = function () {
${renderCssStatements.join( '\n\n' )}
};
var escaped = {
'"': '&quot;',
"'": '&39;',
'&': '&amp;',
'<': '&lt;',
'>': '&gt;'
};
function __escape ( html ) {
return html.replace( /["'&<>]/g, match => escaped[ match ] );
}
` );
const rendered = topLevelStatements.join( '\n\n' );
const pattern = /\[✂(\d+)-(\d+)$/;
const parts = rendered.split( '✂]' );
const finalChunk = parts.pop();
const compiled = new Bundle({ separator: '' });
function addString ( str ) {
compiled.addSource({
content: new MagicString( str )
});
}
parts.forEach( str => {
const chunk = str.replace( pattern, '' );
if ( chunk ) addString( chunk );
const match = pattern.exec( str );
const snippet = code.snip( +match[1], +match[2] );
compiled.addSource({
filename,
content: snippet
});
});
addString( finalChunk );
return {
code: compiled.toString()
};
}