Generating PDFs in Javascript for fun and profit!

Generating PDFs in Javascript for fun and profit!

<strong>Up until recently, creating complex or elegant PDFs in Javascript has been challenging. Here I’m going to show you step-by-step the path of least resistance to beautiful PDFs. Spoiler: recently made possible by docx to PDF conversion in Javascript :-)</strong>

Up until recently, creating complex or elegant PDFs in Javascript has been challenging. Here I’m going to show you step-by-step the path of least resistance to beautiful PDFs. Spoiler: recently made possible by docx to PDF conversion in Javascript :-)

What follows is some of what I will cover in my upcoming talk at PDF Association conference in Seattle in June.

From 1000 feet, here are your three main alternatives:

  • The first is to create the PDF directly, using pdfkitjsPDF, or the higher level pdfmake. Pdfkit is like iText in the Java world. Pdfmake, based on pdfkit, has its own format for representing rich text; it converts this to PDF.
  • The second is to create HTML, then convert that to PDF. These days probably using puppeteer.
  • The third is to create a docx, then convert that to PDF.

Put another way, you can either create the PDF directly, or use HTML or docx as an intermediate format.

Since its now easy to convert docx to PDF in Javascript, the docx approach is the path of least resistance — particularly for business documents (proposals, invoices, contracts etc).

For one thing, often the content will already be in Word document format, making your job easy.

More importantly, its worth thinking up front about ongoing maintenance (changes to content and formatting). Is that something that you as a developer want to be doing, or is it better to enable the business to do this themselves? If its a Word document, then business users can update the document without troubling you.

Creating a docx in Javascript has been easy for some years, but until recently, converting it to PDF from Javascript has the sticking point. Happily, this is now do-able — without invoking some SAAS API, using LibreOffice, or anything like that.

With docx.js you can programmatically build up your Word document (much like pdfkit and jsPDF allow you to build up a PDF). But this probably isn’t a great idea, because for the final PDF to come out looking right, any feature you care to use has to be supported in both the create-docx and docx-to-pdf steps. For example, merged cells in a table, or adding a watermark.

What we want is an easy way to create a docx, and then the confidence that our docx will be converted cleanly to PDF.

For this, a “templating” approach is the answer: basically, you create a docx template with your wanted layout - in Microsoft Word, LibreOffice, Google Docs, Native Documents or whatever - then use the template engine to replace “variables”.

Step 1: populate docx template

Here we’ll use docxtemplater, in node.js.

Say you want a PDF invoice. Since part of the point of using a Word template is that it is easy for business users to make it pretty, let’s start with one of the invoice templates designed by Microsoft and included in Word.

You can see I’ve added some variables (represented with curly braces, as required by docxtemplater).

You can click the image to see the docx in our Word File Editor. Click invoice-template.docx to download/use it with the code which follows.

Being a Javascript library, docxtemplater ingests data in JSON format:

{CustomerName : "Microsoft Corp",
AddressLine1: "One Microsoft Way",
City: "Redmond", State: "WA", Zip: "98052",
Country: "USA",
InvoiceDate : "14 March 2019",
InvoiceNumber: "INV123",
Items: [
{
 Item_Description: "Bananas",
 Item_Price: "5",
 Item_Qty: "10",
 Item_SubTotal: "50"
 },
{
 Item_Description: "Mangoes",
 Item_Price: "10",
 Item_Qty: "4",
 Item_SubTotal: "40"
 }
],
TotalEx:"90", 
SalesTax:"9", 
Shipping:"10", 
TotalPrice:"$109", 
DueDate : "28 March 2019"
}

Notice the Items array. The table row repeats for each of the Items. You can see docxtemplater’s markup for a repeat/loop at the start and end of that table row.

For demo purposes here we’ll provide that inline in our javascript:

var JSZip = require('jszip');
var Docxtemplater = require('docxtemplater');

var fs = require('fs');
var path = require('path');

//Load the docx file as a binary
var content = fs
.readFileSync(path.resolve(__dirname, 'invoice-template.docx'), 'binary');

var zip = new JSZip(content);

var doc = new Docxtemplater();
doc.loadZip(zip);

//set the templateVariables
doc.setData({CustomerName : "Microsoft Corp",
AddressLine1: "One Microsoft Way",
City: "Redmond", State: "WA", Zip: "98052",
Country: "USA",

InvoiceDate : "14 March 2019",
InvoiceNumber: "INV123",
Items: [
{
Item_Description: "Bananas",
Item_Price: "5",
Item_Qty: "10",
Item_SubTotal: "50"
},
{
Item_Description: "Mangoes",
Item_Price: "10",
Item_Qty: "4",
Item_SubTotal: "40"
}
],
TotalEx:"90",
SalesTax:"9",
Shipping:"10",
TotalPrice:"$109",
DueDate : "28 March 2019"
});

try {
// render the document ie replace the variables
doc.render()
}
catch (error) {
var e = {
message: error.message,
name: error.name,
stack: error.stack,
properties: error.properties,
}
console.log(JSON.stringify({error: e}));
throw error;
}

var buf = doc.getZip()
.generate({type: 'nodebuffer'});

// buf is a nodejs buffer, you can either write it to a file or do anything else with it.
fs.writeFileSync(path.resolve(__dirname, 'invoice-instance.docx'), buf);

To try it, install docxtemplater as per its instructions:

npm install docxtemplater
npm install [email protected]

Then its just:

node invoice-template-docx.js

And you get a populated invoice instance:

Notice the table row has been repeated, and all variables replaced.

If you run the code yourself, you can verify the results by opening invoice-instance.docx in your favourite docx editor, or in ours: click here then drag/drop your docx.

Step 2: convert the docx to PDF

So far so good. Now we just need to convert the populated invoice instance to PDF.

For that, we’ll use docx-wasm, a node module we at Native Documents released earlier this year. Our bread and butter at Native Documents is the web-based document editing/viewing component we used above to display invoice-template.docx, and this node module generates PDF output using that Word compatible page layout code. Put another way, the page layout reproduces what Word does so closely that it can also be used for high quality PDF output.

First, install it:

npm install @nativedocuments/docx-wasm

Converting the docx in the node.js buffer object to PDF is then just:

const docx = require("@nativedocuments/docx-wasm");

// init docx engine
docx.init({
ND_DEV_ID: "4H2I80DDEVNAJQSGGIC3K98N8S",
ND_DEV_SECRET: "3CTNJA7DBQFA8UDV2GM8I60N38",
// ND_DEV_ID: "XXXXXXXXXXXXXXXXXXXXXXXXXX", // goto https://developers.nativedocuments.com/ to get a dev-id/dev-secret
// ND_DEV_SECRET: "YYYYYYYYYYYYYYYYYYYYYYYYYY", // you can also set the credentials in the enviroment variables
ENVIRONMENT: "NODE", // required
LAZY_INIT: true // if set to false the WASM engine will be initialized right now, usefull pre-caching (like e.g. for AWS lambda)
}).catch( function(e) {
console.error(e);
});

async function convertHelper(document, exportFct) {
const api = await docx.engine();
await api.load(document);
const arrayBuffer = await apiexportFct;
await api.close();
return arrayBuffer;
}

convertHelper(buf, "exportPDF").then((arrayBuffer) => {
fs.writeFileSync("sample.pdf", new Uint8Array(arrayBuffer));
}).catch((e) => {
console.error(e);
});

You’ll need a ND_DEV_ID, ND_DEV_SECRET pair to use this module. You can get free-tier keys at https://developers.nativedocuments.com/

Copy these into the docx.init call (or alternatively, you can set these as environment vars).

I haven’t posted the PDF here, since it just looks the same as the invoice-instance docx.

Putting it all together

Here is Javascript which combines step 1 and step 2.

// Step 1: generate docx

var JSZip = require('jszip');
var Docxtemplater = require('docxtemplater');

var fs = require('fs');
var path = require('path');

//Load the docx file as a binary
var content = fs
.readFileSync(path.resolve(__dirname, 'template.docx'), 'binary');

var zip = new JSZip(content);

var doc = new Docxtemplater();
doc.loadZip(zip);

//set the templateVariables
doc.setData({CustomerName : "Microsoft Corp",
AddressLine1: "One Microsoft Way",
City: "Redmond", State: "WA", Zip: "98052",
Country: "USA",

InvoiceDate : "14 March 2019",
InvoiceNumber: "INV123",
Items: [
{
Item_Description: "Bananas",
Item_Price: "5",
Item_Qty: "10",
Item_SubTotal: "50"
},
{
Item_Description: "Mangoes",
Item_Price: "10",
Item_Qty: "4",
Item_SubTotal: "40"
}
],
TotalEx:"90",
SalesTax:"9",
Shipping:"10",
TotalPrice:"$109",
DueDate : "28 March 2019"
});

try {
// render the document ie replace the variables
doc.render()
}
catch (error) {
var e = {
message: error.message,
name: error.name,
stack: error.stack,
properties: error.properties,
}
console.log(JSON.stringify({error: e}));
throw error;
}

var buf = doc.getZip()
.generate({type: 'nodebuffer'});

// buf is a nodejs buffer, you can either write it to a file or do anything else with it.
//fs.writeFileSync(path.resolve(__dirname, 'output.docx'), buf);

// Step 2: convert docx to pdf

const docx = require("@nativedocuments/docx-wasm");

// init docx engine
docx.init({
// ND_DEV_ID: "XXXXXXXXXXXXXXXXXXXXXXXXXX", // goto https://developers.nativedocuments.com/ to get a dev-id/dev-secret
// ND_DEV_SECRET: "YYYYYYYYYYYYYYYYYYYYYYYYYY", // you can also set the credentials in the enviroment variables
ENVIRONMENT: "NODE", // required
LAZY_INIT: true // if set to false the WASM engine will be initialized right now, usefull pre-caching (like e.g. for AWS lambda)
}).catch( function(e) {
console.error(e);
});

async function convertHelper(document, exportFct) {
const api = await docx.engine();
await api.load(document);
const arrayBuffer = await apiexportFct;
await api.close();
return arrayBuffer;
}

convertHelper(buf, "exportPDF").then((arrayBuffer) => {
fs.writeFileSync("output.pdf", new Uint8Array(arrayBuffer));
}).catch((e) => {
console.error(e);
});

To try it, download invoice-template.docx then:

node docx-template-to-pdf.js

Deployment Options

A nice way to run this is on AWS Lambda. With Lambda, you get easy scalability, and you aren’t paying for servers when you aren’t using them. More on this in my upcoming talk at PDF Association conference in Seattle in June! In the meantime, docx-to-pdf-on-AWS-Lambda shows you how to do the docx to PDF part on Lambda. Adding the docx templating piece is straightforward.

Its also now possible to convert docx to PDF client-side, in-browser, reducing server loads, and opening the way to offline operation. docx-wasm-client-side shows you how to do the docx to PDF part client-side.

Originally published by Jason Harrop at https://hackernoon.com

Learn More

☞ The Complete JavaScript Course 2019: Build Real Projects!

☞ Become a JavaScript developer - Learn (React, Node,Angular)

☞ JavaScript: Understanding the Weird Parts

☞ Vue JS 2 - The Complete Guide (incl. Vue Router & Vuex)

☞ The Full JavaScript & ES6 Tutorial - (including ES7 & React)

☞ JavaScript - Step By Step Guide For Beginners

☞ The Web Developer Bootcamp

☞ MERN Stack Front To Back: Full Stack React, Redux & Node.js

☞ Visual Studio Code Settings and Extensions for Faster JavaScript Development

☞ Vue.js Authentication System with Node.js Backend

JavaScript Tutorial: if-else Statement in JavaScript

JavaScript Tutorial: if-else Statement in JavaScript

This JavaScript tutorial is a step by step guide on JavaScript If Else Statements. Learn how to use If Else in javascript and also JavaScript If Else Statements. if-else Statement in JavaScript. JavaScript's conditional statements: if; if-else; nested-if; if-else-if. These statements allow you to control the flow of your program's execution based upon conditions known only during run time.

Decision Making in programming is similar to decision making in real life. In programming also we face some situations where we want a certain block of code to be executed when some condition is fulfilled.
A programming language uses control statements to control the flow of execution of the program based on certain conditions. These are used to cause the flow of execution to advance and branch based on changes to the state of a program.

JavaScript’s conditional statements:

  • if
  • if-else
  • nested-if
  • if-else-if

These statements allow you to control the flow of your program’s execution based upon conditions known only during run time.

  • if: if statement is the most simple decision making statement. It is used to decide whether a certain statement or block of statements will be executed or not i.e if a certain condition is true then a block of statement is executed otherwise not.
    Syntax:
if(condition) 
{
   // Statements to execute if
   // condition is true
}

Here, condition after evaluation will be either true or false. if statement accepts boolean values – if the value is true then it will execute the block of statements under it.
If we do not provide the curly braces ‘{‘ and ‘}’ after if( condition ) then by default if statement will consider the immediate one statement to be inside its block. For example,

if(condition)
   statement1;
   statement2;

// Here if the condition is true, if block 
// will consider only statement1 to be inside 
// its block.

Flow chart:

Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate If statement 

var i = 10; 

if (i > 15) 
document.write("10 is less than 15"); 

// This statement will be executed 
// as if considers one statement by default 
document.write("I am Not in if"); 

< /script> 

Output:

I am Not in if
  • if-else: The if statement alone tells us that if a condition is true it will execute a block of statements and if the condition is false it won’t. But what if we want to do something else if the condition is false. Here comes the else statement. We can use the else statement with if statement to execute a block of code when the condition is false.
    Syntax:
if (condition)
{
    // Executes this block if
    // condition is true
}
else
{
    // Executes this block if
    // condition is false
}


Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate If-else statement 

var i = 10; 

if (i < 15) 
document.write("10 is less than 15"); 
else
document.write("I am Not in if"); 

< /script> 

Output:

i is smaller than 15
  • nested-if A nested if is an if statement that is the target of another if or else. Nested if statements means an if statement inside an if statement. Yes, JavaScript allows us to nest if statements within if statements. i.e, we can place an if statement inside another if statement.
    Syntax:
if (condition1) 
{
   // Executes when condition1 is true
   if (condition2) 
   {
      // Executes when condition2 is true
   }
}

Example:

<script type = "text/javaScript"> 

// JavaScript program to illustrate nested-if statement 

var i = 10; 

if (i == 10) { 

// First if statement 
if (i < 15) 
	document.write("i is smaller than 15"); 

// Nested - if statement 
// Will only be executed if statement above 
// it is true 
if (i < 12) 
	document.write("i is smaller than 12 too"); 
else
	document.write("i is greater than 15"); 
} 
< /script> 

Output:

i is smaller than 15
i is smaller than 12 too
  • if-else-if ladder Here, a user can decide among multiple options.The if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the ladder is bypassed. If none of the conditions is true, then the final else statement will be executed.
if (condition)
    statement;
else if (condition)
    statement;
.
.
else
    statement;


Example:

<script type = "text/javaScript"> 
// JavaScript program to illustrate nested-if statement 

var i = 20; 

if (i == 10) 
document.wrte("i is 10"); 
else if (i == 15) 
document.wrte("i is 15"); 
else if (i == 20) 
document.wrte("i is 20"); 
else
document.wrte("i is not present"); 
< /script> 

Output:

i is 20

How to Retrieve full Profile of LinkedIn User using Javascript

How to Retrieve full Profile of LinkedIn User using Javascript

I am trying to retrieve the full profile (especially job history and educational qualifications) of a linkedin user via the Javascript (Fetch LinkedIn Data Using JavaScript)

Here we are fetching LinkedIn data like Username, Email and other fields using JavaScript SDK.

Here we have 2 workarounds.

  1. Configuration of linkedIn developer api
  2. Javascript Code to fetch records

Configuration of linkedIn developer api

In order to fetch records, first we need to create developer api in linkedin which will act as token/identity while fetching data from other linkedin accounts.

So to create api, navigate to https://linkedin.com/developer/apps and click on 'Create Application'.

After navigating, fill in details like name, description and other required fields and then submit.

As we submit, it will create Client ID and Client Secret shown below, which we will be using in our code while communicating to fetch records from other LinkedIn account.

Note: We need to provide localhost Url here under Oauth 2.0. I am using my localhost, but you can probably use other production URLs under Oauth 2.0 where your app is configured. It will make your api  consider the Url as trusted which fetching records.

Javascript Code to fetch records

For getting user details like first name, last name,User image can be written as,

<script type="text/javascript" src="https://platform.linkedin.com/in.js">  
    api_key: XXXXXXX //Client ID  
    onLoad: OnLinkedInFrameworkLoad //Method that will be called on page load  
    authorize: true  
</script>  
<script type="text/javascript">  
    function OnLinkedInFrameworkLoad() {  
        IN.Event.on(IN, "auth", OnLinkedInAuth);  
    }  
  
    function OnLinkedInAuth() {  
        IN.API.Profile("me").result(ShowProfileData);  
    }  
  
    function ShowProfileData(profiles) {  
        var member = profiles.values[0];  
        var id = member.id;  
        var firstName = member.firstName;  
        var lastName = member.lastName;  
        var photo = member.pictureUrl;  
        var headline = member.headline;  
        //use information captured above  
        var stringToBind = "<p>First Name: " + firstName + " <p/><p> Last Name: " + lastName + "<p/><p>User ID: " + id + " and Head Line Provided: " + headline + "<p/>"  
        document.getElementById('profiles').innerHTML = stringToBind;  
    }  
</script>    

Kindly note we need to include 'https://platform.linkedin.com/in.js' as src under script type as it will act on this Javascript SDK provided by Linkedin.

In the same way we can also fetch records of any organization with the companyid as keyword.

<head>  
    <script type="text/javascript" src="https://platform.linkedin.com/in.js">  
        api_key: XXXXXXX ////Client ID  
        onLoad: onLinkedInLoad  
        authorize: true  
    </script>  
</head>  
  
<body>  
    <div id="displayUpdates"></div>  
    <script type="text/javascript">  
        function onLinkedInLoad() {  
            IN.Event.on(IN, "auth", onLinkedInAuth);  
            console.log("On auth");  
        }  
  
        function onLinkedInAuth() {  
            var cpnyID = XXXXX; //the Company ID for which we want updates  
            IN.API.Raw("/companies/" + cpnyID + "/updates?event-type=status-update&start=0&count=10&format=json").result(displayCompanyUpdates);  
            console.log("After auth");  
        }  
  
        function displayCompanyUpdates(result) {  
            var div = document.getElementById("displayUpdates");  
            var el = "<ul>";  
            var resValues = result.values;  
            for (var i in resValues) {  
                var share = resValues[i].updateContent.companyStatusUpdate.share;  
                var isContent = share.content;  
                var isTitled = isContent,  
                    isLinked = isContent,  
                    isDescription = isContent,  
                    isThumbnail = isContent,  
                    isComment = isContent;  
                if (isTitled) {  
                    var title = isContent.title;  
                } else {  
                    var title = "News headline";  
                }  
                var comment = share.comment;  
                if (isLinked) {  
                    var link = isContent.shortenedUrl;  
                } else {  
                    var link = "#";  
                }  
                if (isDescription) {  
                    var description = isContent.description;  
                } else {  
                    var description = "No description";  
                }  
                /* 
                if (isThumbnailz) { 
                var thumbnailUrl = isContent.thumbnailUrl; 
                } else { 
                var thumbnailUrl = "http://placehold.it/60x60"; 
                } 
                */  
                if (share) {  
                    var content = "<a target='_blank' href=" + link + ">" + comment + "</a><br>";  
                    //el += "<li><img src='" + thumbnailUrl + "' alt=''>" + content + "</li>";  
                    el += "<li><div>" + content + "</div></li>";  
                }  
                console.log(share);  
            }  
            el += "</ul>";  
            document.getElementById("displayUpdates").innerHTML = el;  
        }  
    </script>  
</body>  

We can get multiple metadata while fetching records for any any organization. We can get company updates as shown below.

Conclusion

We can also fetch any company specific data like company job updates/post, total likes, comments, and number of views along with a lot of metadata we can fetch which I have shown below.

Thank you for reading !

7 Best Javascript Iframe Libraries

7 Best Javascript Iframe Libraries

Iframes let you build user experiences into embeddable ‘cross-domain components’, which let users interact with other sites without being redirected. I have compiled 7 best Javascript iframe libraries.

Iframes let you build user experiences into embeddable ‘cross-domain components’, which let users interact with other sites without being redirected. I have compiled 7 best Javascript iframe libraries.

1. Zoid

A cross-domain component toolkit, supporting:

  • Render an iframe or popup on a different domain, and pass down props, including objects and functions
  • Call callbacks natively from the child window without worrying about post-messaging or cross-domain restrictions
  • Create and expose components to share functionality from your site to others!
  • Render your component directly as a React, Vue or Angular component!
    It's 'data-down, actions up' style components, but 100% cross-domain using iframes and popups!

Download


2. Postmate

Postmate is a promise-based API built on postMessage. It allows a parent page to speak with a child iFrame across origins with minimal effort.

Download


3. Iframe Resizer

Keep same and cross domain iFrames sized to their content with support for window/content resizing, in page links, nesting and multiple iFrames

Demo

Download


4. Iframely

Embed proxy. Supports over 1800 domains via custom parsers, oEmbed, Twitter Cards and Open Graph

Demo

Download


5. React Frame component

This component allows you to encapsulate your entire React application or per component in an iFrame.

Demo

Download


6. Seamless.js

A seamless iframe makes it so that visitors are unable to distinguish between content within the iframe and content beside the iframe. Seamless.js is a JavaScript library (with no dependencies) that makes working with iframes easy by doing all the seamless stuff for you automatically.

Demo

Download


7. Porthole

A proxy to safely communicate to cross-domain iframes in javascript

Demo

Download


Thank for read!