Merge pull request #50 from singerla/feature-output-stream

Feature output stream

Author: singerla

README.md

@@ -106,6 +106,23 @@ pres.addSlide('graph', 1)
 pres.write(`myPresentation.pptx`).then(summary => {
   console.log(summary)
 })
+
+// It is also possible to get a ReadableStream. 
+// stream() accepts JSZip.JSZipGeneratorOptions for 'nodebuffer' type. 
+const stream = await pres.stream({
+  compressionOptions: {
+    level: 9,
+  },
+})
+// You can e.g. output the pptx archive to stdout instead of writing a file:
+stream.pipe(process.stdout)
+
+// If you need any other output format, you can eventually access 
+// the underlying JSZip instance:
+const finalJSZip = await pres.getJSZip()
+// Convert the output to whatever needed:
+const base64 = await finalJSZip.generateAsync({ type: 'base64' })
+
 ```
 
 

src/automizer.ts

@@ -18,6 +18,7 @@ import * as fs from 'fs';
 import { XmlHelper } from './helper/xml-helper';
 import ModifyPresentationHelper from './helper/modify-presentation-helper';
 import { ContentTracker } from './helper/content-tracker';
+import JSZip, { OutputType } from 'jszip';
 
 /**
  * Automizer
@@ -295,9 +296,7 @@ export default class Automizer implements IPresentationProps {
    * @returns summary object.
    */
   public async write(location: string): Promise<AutomizerSummary> {
-    await this.writeSlides();
-    await this.normalizePresentation();
-    await this.applyModifyPresentationCallbacks();
+    await this.finalizePresentation();
 
     await this.rootTemplate.archive.output(
       this.getLocation(location, 'output'),
@@ -318,6 +317,43 @@ export default class Automizer implements IPresentationProps {
     };
   }
 
+  /**
+   * Create a ReadableStream from output pptx file.
+   * @param generatorOptions - JSZipGeneratorOptions for nodebuffer Output type
+   * @returns Promise<NodeJS.ReadableStream>
+   */
+  public async stream(
+    generatorOptions?: JSZip.JSZipGeneratorOptions<'nodebuffer'>,
+  ): Promise<NodeJS.ReadableStream> {
+    await this.finalizePresentation();
+
+    if (!this.rootTemplate.archive.stream) {
+      throw 'Streaming is not implemented for current archive type';
+    }
+
+    return this.rootTemplate.archive.stream(this.params, generatorOptions);
+  }
+
+  /**
+   * Pass final JSZip instance.
+   * @returns Promise<NodeJS.ReadableStream>
+   */
+  public async getJSZip(): Promise<JSZip> {
+    await this.finalizePresentation();
+
+    if (!this.rootTemplate.archive.getFinalArchive) {
+      throw 'GetFinalArchive is not implemented for current archive type';
+    }
+
+    return this.rootTemplate.archive.getFinalArchive();
+  }
+
+  async finalizePresentation() {
+    await this.writeSlides();
+    await this.normalizePresentation();
+    await this.applyModifyPresentationCallbacks();
+  }
+
   /**
    * Write all slides to archive.
    */

src/dev.ts

@@ -5,12 +5,13 @@ const outputName = 'create-presentation-file-proxy.test.pptx';
 const automizer = new Automizer({
   templateDir: `${__dirname}/../__tests__/pptx-templates`,
   outputDir: `${__dirname}/../__tests__/pptx-output`,
-  archiveType: {
-    mode: 'fs',
-    baseDir: `${__dirname}/../__tests__/pptx-cache`,
-    workDir: outputName,
-    cleanupWorkDir: true,
-  },
+  // Streaming is only implemented for jszip
+  // archiveType: {
+  //   mode: 'fs',
+  //   baseDir: `${__dirname}/../__tests__/pptx-cache`,
+  //   workDir: outputName,
+  //   cleanupWorkDir: true,
+  // },
   rootTemplate: 'RootTemplateWithImages.pptx',
   presTemplates: [
     `RootTemplate.pptx`,
@@ -19,7 +20,7 @@ const automizer = new Automizer({
   ],
   removeExistingSlides: true,
   cleanup: true,
-  compression: 0,
+  compression: 1,
 });
 
 const run = async () => {
@@ -37,7 +38,7 @@ const run = async () => {
     ],
   };
 
-  const result = await automizer
+  const pres = await automizer
     .addSlide('ChartBarsStacked.pptx', 1, (slide) => {
       slide.modifyElement('BarsStacked', [modify.setChartData(dataSmaller)]);
       slide.addElement('ChartBarsStacked.pptx', 1, 'BarsStacked', [
@@ -57,10 +58,20 @@ const run = async () => {
     .addSlide('ChartBarsStacked.pptx', 1, (slide) => {
       slide.addElement('SlideWithImages.pptx', 2, 'imageJPG');
       slide.modifyElement('BarsStacked', [modify.setChartData(dataSmaller)]);
-    })
-    .write(outputName);
+    });
+
+  const stream = await pres.stream({
+    compressionOptions: {
+      level: 9,
+    },
+  });
+
+  const jszip = await pres.getJSZip();
+  const base64 = await jszip.generateAsync({ type: 'base64' });
+  vd(stream);
+
+  // stream.pipe(process.stdout);
 
-  vd(result.duration);
   // vd(pres.rootTemplate.content);
 };
 

src/helper/archive/archive-jszip.ts

@@ -5,6 +5,7 @@ import { AutomizerParams } from '../../types/types';
 import IArchive, { ArchivedFile } from '../../interfaces/iarchive';
 import { XmlDocument } from '../../types/xml-types';
 import path from 'path';
+import { vd } from '../general-helper';
 
 export default class ArchiveJszip extends Archive implements IArchive {
   archive: JSZip;
@@ -87,6 +88,27 @@ export default class ArchiveJszip extends Archive implements IArchive {
     });
   }
 
+  async stream(
+    params: AutomizerParams,
+    options?: JSZip.JSZipGeneratorOptions<'nodebuffer'>,
+  ): Promise<NodeJS.ReadableStream> {
+    this.setOptions(params);
+
+    await this.writeBuffer(this);
+
+    const mergedOptions = {
+      ...this.options,
+      ...options,
+    };
+
+    return this.archive.generateNodeStream(mergedOptions);
+  }
+
+  async getFinalArchive(): Promise<JSZip> {
+    await this.writeBuffer(this);
+    return this.archive;
+  }
+
   async getContent(params: AutomizerParams): Promise<Buffer> {
     this.setOptions(params);
 

src/helper/archive/archive.ts

@@ -44,10 +44,6 @@ export default class Archive {
     }
   }
 
-  fromBuffer(relativePath) {
-    return this.buffer.find((file) => file.relativePath === relativePath);
-  }
-
   setOptions(params: AutomizerParams): void {
     if (params.compression > 0) {
       this.options.compression = 'DEFLATE';
@@ -56,4 +52,8 @@ export default class Archive {
       };
     }
   }
+
+  fromBuffer(relativePath) {
+    return this.buffer.find((file) => file.relativePath === relativePath);
+  }
 }

src/interfaces/iarchive.ts

@@ -1,6 +1,6 @@
 import ArchiveJszip from '../helper/archive/archive-jszip';
 import { AutomizerParams } from '../types/types';
-import { InputType } from 'jszip';
+import JSZip, { InputType } from 'jszip';
 import { XmlDocument } from '../types/xml-types';
 import ArchiveFs from '../helper/archive/archive-fs';
 
@@ -26,4 +26,10 @@ export default interface IArchive {
   remove: (file: string) => Promise<void>;
   output: (location: string, params: AutomizerParams) => Promise<void>;
   getContent?: (params: AutomizerParams) => Promise<Buffer>;
+  getArchive?: (params: AutomizerParams) => Promise<Buffer>;
+  stream?: (
+    params: AutomizerParams,
+    options: JSZip.JSZipGeneratorOptions<'nodebuffer'>,
+  ) => Promise<NodeJS.ReadableStream>;
+  getFinalArchive?: () => Promise<JSZip>;
 }