Merge pull request #15 from bjrmatos/master

support waitForJS execution in phantom web page (callback based)

README.md

@@ -45,6 +45,8 @@ conversion({
 	footer: "<h2>foo</h2>",
 	url: "http://jsreport.net",//set direct url instead of html
 	printDelay: 0,//time in ms to wait before printing into pdf
+	waitForJS: true,//set to true to enable programmatically specify (via Javascript of the page) when the pdf printing starts (see Programmatic pdf printing section for an example)
+	waitForJSVarName: //name of the variable that will be used as a printing trigger, defaults to "PHANTOM_HTML_TO_PDF_READY" (see Programmatic pdf printing section for an example)
 	allowLocalFilesAccess: false,//set to true to allow request starting with file:///
 	paperSize: {
 		format, orientation, margin, width, height, headerHeight, footerHeight
@@ -72,6 +74,38 @@ conversion.kill();
 ##Page numbers
 Use directives `{#pageNum}` and `{#numPages}` inside header or footer to add current page number resp. total number of pages.
 
+##Programmatic pdf printing
+If you need to programmatic trigger the pdf printing process (because you need to calculate some values or do something async in your page before printing) you can enable the `waitForJS` local option, when `waitForJS` is set to true the pdf printing will wait until you set a variable to true in your page, by default the name of the variable is `PHANTOM_HTML_TO_PDF_READY` but you can customize it via `waitForJSVarName` option.
+
+**Example:**
+
+local options:
+```js
+conversion({
+	html: "<custom html here>",
+	waitForJS: true,
+	viewportSize: {
+		width: 600,
+		height: 600
+	},
+	format: {
+		quality: 100
+	}
+}, cb);
+```
+
+custom html:
+```html
+<h1></h1>
+<script>
+	// do some calculations or something async
+	setTimeout(function() {
+		window.PHANTOM_HTML_TO_PDF_READY = true; //this will start the pdf printing
+	}, 500);
+</script>
+```
+
+
 ##Further notes
 You may find some further information and usage examples in the [jsreport documentation](http://jsreport.net/learn/phantom-pdf) or try pdf printing in the [online playground](https://playground.jsreport.net/#/playground/xykdJcxR5).
 

lib/conversion.js

@@ -42,6 +42,11 @@ function convert(opt, cb) {
     opt.viewportSize = opt.viewportSize || {};
     opt.paperSize = opt.paperSize || {};
     opt.settings = opt.settings || {};
+    opt.waitForJSVarName = opt.waitForJSVarName  || 'PHANTOM_HTML_TO_PDF_READY';
+
+    if (opt.waitForJS && opt.settings.javascriptEnabled === false) {
+        throw new Error('can\'t use waitForJS option if settings.javascriptEnabled is not activated');
+    }
 
     var id = uuid();
 

lib/dedicatedProcessStrategy.js

@@ -41,11 +41,16 @@ module.exports = function(options, requestOptions, id, cb) {
         });
 
         setTimeout(function() {
+            var timeoutErr;
+
             if (isDone)
                 return;
 
             isDone = true;
-            cb(new Error("Timeout when executing in phantom"));
+            timeoutErr = new Error("Timeout when executing in phantom");
+            timeoutErr.phantomTimeout = true;
+
+            cb(timeoutErr);
         }, requestOptions.timeout || options.timeout);
     });
 };

lib/scripts/conversionScriptPart.js

@@ -1,3 +1,5 @@
+var pageJSisDone = body.waitForJS ? false : true;
+
 page.viewportSize = {
     width: body.viewportSize.width || 600,
     height: body.viewportSize.height || 600
@@ -21,6 +23,32 @@ page.onResourceRequested = function (request, networkRequest) {
     if (request.url.lastIndexOf("file://", 0) === 0 && request.url.lastIndexOf("file:///", 0) !== 0) {
         networkRequest.changeUrl(request.url.replace("file://", "http://"));
     }
+
+    if (body.waitForJS && request.url.lastIndexOf("http://intruct-javascript-ending", 0) === 0) {
+        pageJSisDone = true;
+    }
+};
+
+page.onInitialized = function() {
+    // inject function to the page in order to the client can instruct the ending of its JS
+    if (body.waitForJS) {
+        page.evaluate(function(varName) {
+            if (typeof Object.defineProperty === 'function') {
+                Object.defineProperty(window, varName, {
+                    set: function(val) {
+                        if (!val)
+                            return;
+
+                        if (val === true) {
+                            var scriptNode = document.createElement("script");
+                            scriptNode.src = 'http://intruct-javascript-ending';
+                            document.body.appendChild(scriptNode);
+                        }
+                    }
+                });
+            }
+        }, body.waitForJSVarName);
+    }
 };
 
 page.open(body.url, function () {
@@ -76,8 +104,18 @@ page.open(body.url, function () {
     }
 
     setTimeout(function () {
+        resolvePage()
+    }, body.printDelay || 0);
+
+    function resolvePage() {
+        if (body.waitForJS && !pageJSisDone) {
+            setTimeout(function() {
+                resolvePage();
+            }, 100);
+            return;
+        }
+
         page.render(body.output, body.format);
         respond(page, body);
-
-    }, body.printDelay || 0);
+    }
 });

lib/scripts/standaloneScriptPart.js

@@ -16,7 +16,16 @@ stream.close();
 
 function respond(page, body) {
     console.log(body.numberOfPages);
-    phantom.exit(0);
+
+    // Work-around to avoid "Unsafe JavaScript attempt to access frame" warning in PhantomJS 1.9.8.
+    // See: https://github.com/ariya/phantomjs/issues/12697
+    // since we rely on stdout for the dedicated-process strategy this work-around
+    // ensures the phantom process don't log anything we don't want
+    page.close();
+
+    setTimeout(function() {
+        phantom.exit(0);
+    }, 0);
 }
 
 $conversion

lib/serverStrategy.js

@@ -15,6 +15,7 @@ function ensurePhantom(cb) {
         return;
 
     starting = true;
+    // TODO: handle callback err for .start
     phantom.start(function() {
         started = true;
         starting = false;
@@ -32,8 +33,14 @@ module.exports = function(options, requestOptions, id, cb) {
             return cb(err);
 
         phantom.execute(requestOptions, function (err, res) {
-            if (err)
+            if (err) {
+                // if the error is a timeout from phantom-workers
+                if (err.message === "Timeout") {
+                    err.phantomTimeout = true;
+                }
+
                 return cb(err);
+            }
 
             cb(null, {
                 stream: fs.createReadStream(requestOptions.output),

package.json

@@ -19,7 +19,7 @@
     "url": "[email protected]:pofider/phantom-html-to-pdf.git"
   },
   "dependencies": {
-    "phantom-workers": "0.3.0",
+    "phantom-workers": "0.3.1",
     "phantomjs": "1.9.17",
     "underscore": "1.8.2",
     "uuid": "2.0.1"
@@ -29,7 +29,7 @@
     "should": "5.0.1"
   },
   "scripts": {
-    "test": "node lib/prepareScripts.js && mocha test/test.js",
+    "test": "node lib/prepareScripts.js && mocha test/test.js --timeout 4000",
     "postinstall": "node lib/prepareScripts.js"
   },
   "main": "index.js",

test/test.js

@@ -48,7 +48,7 @@ describe("phantom html to pdf", function () {
             });
         });
 
-        it ('should create a pdf file ignoring ssl errors', function(done) {
+        it('should create a pdf file ignoring ssl errors', function(done) {
             conversion({
                 url: 'https://sygris.com'
             }, function(err, res) {
@@ -61,6 +61,75 @@ describe("phantom html to pdf", function () {
                 done();
             });
         });
+
+        it('should wait for page js execution', function(done) {
+            conversion({
+                html: '<h1>aa</h1><script>window.PHANTOM_HTML_TO_PDF_READY = true;</script>',
+                waitForJS: true
+            }, function(err, res) {
+                if (err) {
+                    return done(err);
+                }
+
+                res.numberOfPages.should.be.eql(1);
+                res.stream.should.have.property("readable");
+                done();
+            });
+        });
+
+        it('should wait for page async js execution', function(done) {
+            conversion({
+                html: '<h1>aa</h1><script>setTimeout(function() { window.PHANTOM_HTML_TO_PDF_READY = true; }, 200);</script>',
+                waitForJS: true
+            }, function(err, res) {
+                if (err) {
+                    return done(err);
+                }
+
+                res.numberOfPages.should.be.eql(1);
+                res.stream.should.have.property("readable");
+                done();
+            });
+        });
+
+        it('should allow define a custom var name for page js execution', function(done) {
+            conversion({
+                html: '<h1>aa</h1><script>window.ready = true;</script>',
+                waitForJS: true,
+                waitForJSVarName: 'ready'
+            }, function(err, res) {
+                if (err) {
+                    return done(err);
+                }
+
+                res.numberOfPages.should.be.eql(1);
+                res.stream.should.have.property("readable");
+                done();
+            });
+        });
+
+        it('should throw timeout when waiting for page js execution', function(done) {
+            //since phantom-worker doesn't support a timeout per request
+            //we increase the test timeout
+            this.timeout(20000);
+
+            conversion({
+                html: '<h1>aa</h1>',
+                timeout: 500,
+                waitForJS: true
+            }, function(err, res) {
+                if (!err) {
+                    return done(new Error('the conversion doesn\'t throw error'));
+                }
+
+                if (err.phantomTimeout !== undefined) {
+                    should(err.phantomTimeout).be.eql(true);
+                    done();
+                } else {
+                    done(err);
+                }
+            });
+        });
     }
 
     rmDir = function (dirPath) {