Merge pull request mooz#36 from roest01/feature/single-image-result

Feature to convert whole file and combine output images
roest01 · May 7, 2018 · 039ac28 · 039ac28
2 parents 3809535 + 31edb6b
commit 039ac28
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Showing 3 changed files with 135 additions and 10 deletions.
diff --git a/README.md b/README.md
@@ -19,6 +19,7 @@ Ensure you have `convert`, `gs`, and `pdfinfo` (part of poppler) commands.
 
 ## Usage
 
+#### Convert single page:
 ```javascript
 var PDFImage = require("pdf-image").PDFImage;
 
@@ -29,6 +30,29 @@ pdfImage.convertPage(0).then(function (imagePath) {
 });
 ```
 
+#### Convert full file
+```javascript
+var PDFImage = require("pdf-image").PDFImage;
+
+var pdfImage = new PDFImage("/tmp/slide.pdf");
+pdfImage.convertFile().then(function (imagePaths) {
+  // [ /tmp/slide-0.png, /tmp/slide-1.png ]
+});
+
+
+```
+#### Convert full file and merge result into single image
+```javascript
+var PDFImage = require("pdf-image").PDFImage;
+var pdfImage = new PDFImage("/tmp/slide.pdf", {
+  combinedImage: true
+});
+
+pdfImage.convertFile().then(function (imagePaths) {
+   // /tmp/slide.png 
+});
+```
+
 ## Express
 
 Following example shows an example of pdf-image in Express, which gives
@@ -56,14 +80,10 @@ URLs for each pages of a PDF like
 Following example shows an example of how to add imagemagick command-line options (you can find the complete list here -> http://www.imagemagick.org/script/convert.php):
 
 ```javascript
-var theOptions = {};
-theOptions.convertOptions = {};
-theOptions.convertOptions["-resize"] =  "2000x2000";
-theOptions.convertOptions["-quality"] =  "75";
-```
-
-And then just change the instantiation of a new PDFImage by:
-
-```javascript
-var pdfImage = new PDFImage(pdfPath, theOptions);
+var pdfImage = new PDFImage(pdfPath, {
+  convertOptions: {
+    "-resize": "2000x2000",
+    "-quality": "75"
+  }
+});
 ```
diff --git a/index.js b/index.js
@@ -16,6 +16,7 @@ function PDFImage(pdfFilePath, options) {
   this.setConvertOptions(options.convertOptions);
   this.setConvertExtension(options.convertExtension);
   this.useGM = options.graphicsMagick || false;
+  this.combinedImage = options.combinedImage || false;
 
   this.outputDirectory = options.outputDirectory || path.dirname(pdfFilePath);
 }
@@ -65,6 +66,12 @@ PDFImage.prototype = {
       this.pdfFileBaseName + "-" + pageNumber + "." + this.convertExtension
     );
   },
+  getOutputImagePathForFile: function () {
+    return path.join(
+      this.outputDirectory,
+      this.pdfFileBaseName + "." + this.convertExtension
+    );
+  },
   setConvertOptions: function (convertOptions) {
     this.convertOptions = convertOptions || {};
   },
@@ -85,6 +92,14 @@ PDFImage.prototype = {
       pdfFilePath, pageNumber, outputImagePath
     );
   },
+  constructCombineCommandForFile: function (imagePaths) {
+    return util.format(
+      "%s -append %s \"%s\"",
+      this.useGM ? "gm convert" : "convert",
+      imagePaths.join(' '),
+      this.getOutputImagePathForFile()
+    );
+  },
   constructConvertOptions: function () {
     return Object.keys(this.convertOptions).sort().map(function (optionName) {
       if (this.convertOptions[optionName] !== null) {
@@ -94,6 +109,57 @@ PDFImage.prototype = {
       }
     }, this).join(" ");
   },
+  combineImages: function(imagePaths) {
+    var pdfImage = this;
+    var combineCommand = pdfImage.constructCombineCommandForFile(imagePaths);
+    return new Promise(function (resolve, reject) {
+      exec(combineCommand, function (err, stdout, stderr) {
+        if (err) {
+          return reject({
+            message: "Failed to combine images",
+            error: err,
+            stdout: stdout,
+            stderr: stderr
+          });
+        }
+        exec("rm "+imagePaths.join(' ')); //cleanUp
+        return resolve(pdfImage.getOutputImagePathForFile());
+      });
+    });
+  },
+  convertFile: function () {
+    var pdfImage = this;
+    return new Promise(function (resolve, reject) {
+      pdfImage.numberOfPages().then(function (totalPages) {
+        var convertPromise = new Promise(function (resolve, reject){
+          var imagePaths = [];
+          for (var i = 0; i < totalPages; i++) {
+            pdfImage.convertPage(i).then(function(imagePath){
+              imagePaths.push(imagePath);
+              if (imagePaths.length === parseInt(totalPages)){
+                imagePaths.sort(); //because of asyc pages we have to reSort pages
+                resolve(imagePaths);
+              }
+            }).catch(function(error){
+              reject(error);
+            });
+          }
+        });
+
+        convertPromise.then(function(imagePaths){
+          if (pdfImage.combinedImage){
+            pdfImage.combineImages(imagePaths).then(function(imagePath){
+              resolve(imagePath);
+            });
+          } else {
+            resolve(imagePaths);
+          }
+        }).catch(function(error){
+          reject(error);
+        });
+      });
+    });
+  },
   convertPage: function (pageNumber) {
     var pdfFilePath     = this.pdfFilePath;
     var outputImagePath = this.getOutputImagePathForPage(pageNumber);

diff --git a/tests/test-main.js b/tests/test-main.js
@@ -7,6 +7,7 @@ describe("PDFImage", function () {
   let pdfPath = "/tmp/test.pdf";
   let pdfImage;
   let generatedFiles = [];
+  this.timeout(7000);
 
   before(function(done){
     fs.createReadStream('tests/test.pdf').pipe(fs.createWriteStream(pdfPath));
@@ -39,13 +40,20 @@ describe("PDFImage", function () {
       .equal("/tmp/test-2.png");
     expect(pdfImage.getOutputImagePathForPage(1000))
       .equal("/tmp/test-1000.png");
+    expect(pdfImage.getOutputImagePathForFile())
+      .equal("/tmp/test.png");
   });
 
   it("should return correct convert command", function () {
     expect(pdfImage.constructConvertCommandForPage(1))
       .equal('convert "/tmp/test.pdf[1]" "/tmp/test-1.png"');
   });
 
+  it("should return correct convert command to combine images", function () {
+    expect(pdfImage.constructCombineCommandForFile(['/tmp/test-0.png', '/tmp/test-1.png']))
+      .equal('convert -append /tmp/test-0.png /tmp/test-1.png "/tmp/test.png"');
+  });
+
   it("should use gm when you ask it to", function () {
     pdfImage = new PDFImage(pdfPath, {graphicsMagick: true});
     expect(pdfImage.constructConvertCommandForPage(1))
@@ -93,6 +101,37 @@ describe("PDFImage", function () {
     });
   });
 
+  it("should convert all PDF's pages to files", function () {
+    return new Promise(function(resolve, reject) {
+      pdfImage.convertFile().then(function (imagePaths) {
+        imagePaths.forEach(function(imagePath){
+          expect(fs.existsSync(imagePath)).to.be.true;
+          generatedFiles.push(imagePath);
+        });
+        resolve();
+      }).catch(function(err){
+        reject(err);
+      });
+    });
+  });
+
+  it("should convert all PDF's pages to single image", function () {
+    return new Promise(function(resolve, reject){
+      let pdfImageCombined = new PDFImage(pdfPath, {
+        combinedImage: true,
+      });
+
+      pdfImageCombined.convertFile().then(function (imagePath) {
+        expect(imagePath).to.equal("/tmp/test.png");
+        expect(fs.existsSync(imagePath)).to.be.true;
+        generatedFiles.push(imagePath);
+        resolve();
+      }).catch(function (error) {
+        reject(error);
+      });
+    })
+  });
+
   it("should return # of pages", function () {
     return new Promise(function(resolve, reject) {
       pdfImage.numberOfPages().then(function (numberOfPages) {