PojoViz - Plain Old JavaScript Object Visualization

%PojoViz is a tool to analyze the plain objects of a JavaScript library/framework by finding all the relationships found among the library entry point (typically a global variable) and the objects/functions linked to it

Note: this project was developed to work with Google Chrome, it's suggested that you use this browser for a complete experience


How many times did you find an awesome library/framework and wanted to see how it's structured just for fun?


  • Export any graph to a simple JSON file consisting of node/edges
  • Two renderers: SVG (d3) and WebGL (threejs)
  • Analyze your preferred library/framework hosted on http://cdnjs.com

The algorithm

%PojoViz works in three phases:

Configuration phase

  • The library's representation in %PojoViz configured with the following properties:

    • Global access point of the library (e.g. window.d3)
    • The maximum number of levels allowed while running the DFS algorithm
    • The src of the script (if it's an external resource)
    • The forbidden objects which are discarded when found by the DFS algorithm

Process phase

  • After the configuration is read %PojoViz's ObjectAnalyzer class analyzes the properties of this object and if any of them is an object/function constructor (configurable in settings) then ObjectAnalyzer will follow this link recursively saving each object/function found in a HashMap
  • ObjectAnalyzer will also in the process save the links (edges of the graph) found (from an object property to an object/function constructor) in an array for later use
  • The main program will ask ObjectAnalyzer for a JSON representation of the nodes/edges of the generated graph
  • Dagre's layout program is executed with the generated JSON which returns the positions of each node in a 2D plane

Rendering phase

  • The chosen renderer (d3 or three.js) builds the graph provided by the process phase by rendering the nodes' properties and edges

Hello Pojoviz

Let's say we want to analyze the structure of the mother of all objects, the Object function, in the following example each link analyzed is marked with -->:

 + length (number)
 ... many properties here
 + keys (function)
 +--> prototype (object, the Object's prototype)
 +--> [[Prototype]] (the hidden link to its prototype, which is Function.prototype since Object is a function)

     + toString (function, not a function constructor so it's not saved)
     + constructor (function constructor but it's already saved)
     ... many properties here

    Function.prototype (following the hidden [[Prototype]] link of the Object function)
     + bind (function)
     + toString (fucntion)
     ... many properties here
     +--> constructor (function, the object Function)
     + [[Prototype]] (points to Object.prototype but it's already saved)

        + length (number)
        ... many properties here
        + prototype (points to Function.prototype which is already saved)
        + [[Prototype]] (points to Function.prototype too)


Special thanks once again to @mrdoob the author of three.js and to @mbostock author of d3.

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