import { Component, NgModule, Injectable, Compiler, ViewContainerRef, ModuleWithProviders, Type,

Optional

} from '@angular/core';

import { CommonModule } from '@angular/common'; import { BrowserModule } from '@angular/platform-browser';

import { cloneDeep } from 'lodash';

export interface CompileOptions { template: string; container: ViewContainerRef; imports?: Array<Type<any> | ModuleWithProviders | any[]>; context?: any, onCompiled?: Function, onError?: Function;

module?: NgModule;

} const cache : any = {};

export class CompileServiceConfig { module: NgModule } let SingletonDefaultModule: NgModule;

@Injectable() export class CompileService { constructor( private compiler: Compiler,

@Optional() config: CompileServiceConfig,

) {

if (config !== undefined && config !== null) { if (config.module !== undefined && config.module !== null) { SingletonDefaultModule = config.module; }

}

} public async compile(opts: CompileOptions) { try { const factory = await this.createFactory(opts); opts.container.clear(); const cmp : any = opts.container.createComponent(factory); cmp.instance.context = opts.context; } catch (e) { if (opts.onError) { opts.onError(e) } else { console.error(e); } } } private async createFactory(opts: CompileOptions) { const cacheKey = opts.template; if (Object.keys(cache).indexOf(cacheKey) > -1) { return cache[cacheKey]; }

cache[cacheKey] = (async() => {

try { @Component({ template: opts.template }) class TemplateComponent { context: any }

let module : NgModule = {}; if (opts.module !== undefined) {

module = cloneDeep(opts.module);

} else if (SingletonDefaultModule !== undefined && SingletonDefaultModule !== null) {

module = cloneDeep(SingletonDefaultModule);

} module.imports = module.imports || []; module.imports.push( CommonModule ); module.imports.push( BrowserModule ); if (opts.imports !== undefined) { module.imports = module.imports.concat(opts.imports) } if (module.declarations === undefined) { module.declarations = [ TemplateComponent ]; } else { module.declarations.push(TemplateComponent); } @NgModule(module) class TemplateModule { } const component = await this.compiler.compileModuleAndAllComponentsAsync(TemplateModule); const factory = component.componentFactories.find((comp) => comp.componentType === TemplateComponent ); cache[cacheKey] = factory; if (opts.onCompiled) { opts.onCompiled(component); } return factory; } catch (e) { delete cache[cacheKey]; throw e;

}

})();

return cache[cacheKey]; } }