discourse/lib/javascripts/widget-hbs-compiler.js.es6

352 lines
9.2 KiB
JavaScript

function resolve(path) {
if (path.indexOf("settings") === 0 || path.indexOf("transformed") === 0) {
return `this.${path}`;
}
return path;
}
function sexpValue(value) {
if (!value) {
return;
}
let pValue = value.original;
if (value.type === "StringLiteral") {
return JSON.stringify(pValue);
} else if (value.type === "SubExpression") {
return sexp(value);
}
return pValue;
}
function pairsToObj(pairs) {
let result = [];
pairs.forEach(p => {
result.push(`"${p.key}": ${sexpValue(p.value)}`);
});
return `{ ${result.join(", ")} }`;
}
function i18n(node) {
let key = sexpValue(node.params[0]);
let hash = node.hash;
if (hash.pairs.length) {
return `I18n.t(${key}, ${pairsToObj(hash.pairs)})`;
}
return `I18n.t(${key})`;
}
function sexp(value) {
if (value.path.original === "hash") {
return pairsToObj(value.hash.pairs);
}
if (value.path.original === "concat") {
let result = [];
value.params.forEach(p => {
result.push(sexpValue(p));
});
return result.join(" + ");
}
if (value.path.original === "i18n") {
return i18n(value);
}
}
function valueOf(value) {
if (value.type === "SubExpression") {
return sexp(value);
} else if (value.type === "PathExpression") {
return value.original;
} else if (value.type === "StringLiteral") {
return JSON.stringify(value.value);
}
}
function argValue(arg) {
return valueOf(arg.value);
}
function useHelper(state, name) {
let id = state.helpersUsed[name];
if (!id) {
id = ++state.helperNumber;
state.helpersUsed[name] = id;
}
return `__h${id}`;
}
function mustacheValue(node, state) {
let path = node.path.original;
switch (path) {
case "attach":
let widgetName = argValue(node.hash.pairs.find(p => p.key === "widget"));
let attrs = node.hash.pairs.find(p => p.key === "attrs");
if (attrs) {
return `this.attach(${widgetName}, ${argValue(attrs)})`;
}
return `this.attach(${widgetName}, attrs)`;
break;
case "yield":
return `this.attrs.contents()`;
break;
case "i18n":
return i18n(node);
break;
case "avatar":
let template = argValue(node.hash.pairs.find(p => p.key === "template"));
let username = argValue(node.hash.pairs.find(p => p.key === "username"));
let size = argValue(node.hash.pairs.find(p => p.key === "size"));
return `${useHelper(
state,
"avatar"
)}(${size}, { template: ${template}, username: ${username} })`;
break;
case "date":
return `${useHelper(state, "dateNode")}(${valueOf(node.params[0])})`;
break;
case "d-icon":
return `${useHelper(state, "iconNode")}(${valueOf(node.params[0])})`;
break;
default:
// Shortcut: If our mustach has hash arguments, we can assume it's attaching.
// For example `{{home-logo count=123}}` can become `this.attach('home-logo, { "count": 123 });`
let hash = node.hash;
if (hash.pairs.length) {
let widgetString = JSON.stringify(path);
// magic: support applying of attrs. This is commonly done like `{{home-logo attrs=attrs}}`
let firstPair = hash.pairs[0];
if (firstPair.key === "attrs") {
return `this.attach(${widgetString}, ${firstPair.value.original})`;
}
return `this.attach(${widgetString}, ${pairsToObj(hash.pairs)})`;
}
if (node.escaped) {
return `${resolve(path)}`;
} else {
return `new ${useHelper(state, "rawHtml")}({ html: '<span>' + ${resolve(
path
)} + '</span>'})`;
}
break;
}
}
class Compiler {
constructor(ast) {
this.idx = 0;
this.ast = ast;
this.state = {
helpersUsed: {},
helperNumber: 0
};
}
newAcc() {
return `_a${this.idx++}`;
}
processNode(parentAcc, node) {
let instructions = [];
let innerAcc;
switch (node.type) {
case "Program":
node.body.forEach(bodyNode => {
instructions = instructions.concat(
this.processNode(parentAcc, bodyNode)
);
});
break;
case "ElementNode":
innerAcc = this.newAcc();
instructions.push(`var ${innerAcc} = [];`);
node.children.forEach(child => {
instructions = instructions.concat(this.processNode(innerAcc, child));
});
if (node.attributes.length) {
let attributes = [];
node.attributes.forEach(a => {
const name = a.name === "class" ? "className" : a.name;
if (a.value.type === "MustacheStatement") {
attributes.push(
`"${name}":${mustacheValue(a.value, this.state)}`
);
} else {
attributes.push(`"${name}":"${a.value.chars}"`);
}
});
const attrString = `{${attributes.join(", ")}}`;
instructions.push(
`${parentAcc}.push(virtualDom.h('${
node.tag
}', ${attrString}, ${innerAcc}));`
);
} else {
instructions.push(
`${parentAcc}.push(virtualDom.h('${node.tag}', ${innerAcc}));`
);
}
break;
case "TextNode":
return `${parentAcc}.push(${JSON.stringify(node.chars)});`;
case "MustacheStatement":
const value = mustacheValue(node, this.state);
if (value) {
instructions.push(`${parentAcc}.push(${value});`);
}
break;
case "BlockStatement":
let negate = "";
switch (node.path.original) {
case "unless":
negate = "!";
case "if":
instructions.push(
`if (${negate}${resolve(node.params[0].original)}) {`
);
node.program.body.forEach(child => {
instructions = instructions.concat(
this.processNode(parentAcc, child)
);
});
if (node.inverse) {
instructions.push(`} else {`);
node.inverse.body.forEach(child => {
instructions = instructions.concat(
this.processNode(parentAcc, child)
);
});
}
instructions.push(`}`);
break;
case "each":
const collection = resolve(node.params[0].original);
instructions.push(`if (${collection} && ${collection}.length) {`);
instructions.push(
` ${collection}.forEach(${node.program.blockParams[0]} => {`
);
node.program.body.forEach(child => {
instructions = instructions.concat(
this.processNode(parentAcc, child)
);
});
instructions.push(` });`);
instructions.push("}");
break;
}
break;
default:
break;
}
return instructions.join("\n");
}
compile() {
return this.processNode("_r", this.ast);
}
}
function compile(template) {
const preprocessor = Ember.__loader.require("@glimmer/syntax");
const compiled = preprocessor.preprocess(template);
const compiler = new Compiler(compiled);
let code = compiler.compile();
let imports = "";
Object.keys(compiler.state.helpersUsed).forEach(h => {
let id = compiler.state.helpersUsed[h];
imports += `var __h${id} = Discourse.__widget_helpers.${h}; `;
});
return `function(attrs, state) { ${imports}var _r = [];\n${code}\nreturn _r; }`;
}
exports.compile = compile;
function error(path, state, msg) {
const filename = state.file.opts.filename;
return path.replaceWithSourceString(
`function() { console.error("${filename}: ${msg}"); }`
);
}
exports.WidgetHbsCompiler = function(babel) {
let t = babel.types;
return {
visitor: {
ImportDeclaration(path, state) {
let node = path.node;
if (
t.isLiteral(node.source, { value: "discourse/widgets/hbs-compiler" })
) {
let first = node.specifiers && node.specifiers[0];
if (!t.isImportDefaultSpecifier(first)) {
let input = state.file.code;
let usedImportStatement = input.slice(node.start, node.end);
let msg = `Only \`import hbs from 'discourse/widgets/hbs-compiler'\` is supported. You used: \`${usedImportStatement}\``;
throw path.buildCodeFrameError(msg);
}
state.importId =
state.importId ||
path.scope.generateUidIdentifierBasedOnNode(path.node.id);
path.scope.rename(first.local.name, state.importId.name);
path.remove();
}
},
TaggedTemplateExpression(path, state) {
if (!state.importId) {
return;
}
let tagPath = path.get("tag");
if (tagPath.node.name !== state.importId.name) {
return;
}
if (path.node.quasi.expressions.length) {
return error(
path,
state,
"placeholders inside a tagged template string are not supported"
);
}
let template = path.node.quasi.quasis
.map(quasi => quasi.value.cooked)
.join("");
try {
path.replaceWithSourceString(compile(template));
} catch (e) {
return error(path, state, e.toString());
}
}
}
};
};