gojs/extensions/HyperlinkText.js

Interactive diagrams, charts, and graphs, such as trees, flowcharts, orgcharts, UML, BPMN, or business diagrams

"use strict";
/*
*  Copyright (C) 1998-2020 by Northwoods Software Corporation. All Rights Reserved.
*/

// A "HyperlinkText" is either a TextBlock or a Panel containing a TextBlock that when clicked
// opens a new browser window with a given or computed URL.
// When the user's mouse passes over a "HyperlinkText", the text is underlined.
// When the mouse hovers over a "HyperlinkText", it shows a tooltip that displays the URL.

// This "HyperlinkText" builder is not pre-defined in the GoJS library, so you will need to load this definition.

// Typical usages:
//    $("HyperlinkText", "https://gojs.net", "Visit GoJS")
//
//    $("HyperlinkText",
//        function(node) { return "https://gojs.net/" + node.data.version; },
//        function(node) { return "Visit GoJS version " + node.data.version; })
//
//    $("HyperlinkText",
//        function(node) { return "https://gojs.net/" + node.data.version; },
//        $(go.Panel, "Auto",
//            $(go.Shape, ...),
//            $(go.TextBlock, ...)
//        )
//    )

// The first argument to the "HyperlinkText" builder should be either the URL string or a function
// that takes the data-bound Panel and returns the URL string.
// If the URL string is empty or if the function returns an empty string,
// the text will not be underlined on a mouse-over and a click has no effect.

// The second argument to the "HyperlinkText" builder may be either a string to display in a TextBlock,
// or a function that takes the data-bound Panel and returns the string to display in a TextBlock.
// If no text string or function is provided, it assumes all of the arguments are used to
// define the visual tree for the "HyperlinkText", in the normal fashion for a Panel.

// The result is either a TextBlock or a Panel.

go.GraphObject.defineBuilder("HyperlinkText", function(args) {
  // the URL is required as the first argument, either a string or a side-effect-free function returning a string
  var url = go.GraphObject.takeBuilderArgument(args, undefined, function(x) { return typeof x === "string" || typeof x === "function"; });
  // the text for the HyperlinkText is the optional second argument, either a string or a side-effect-free function returning a string
  var text = go.GraphObject.takeBuilderArgument(args, null, function(x) { return typeof x === "string" || typeof x === "function"; });

  // see if the visual tree is supplied in the arguments to the "HyperlinkText"
  var anyGraphObjects = false;
  for (var i = 0; i < args.length; i++) {
    var a = args[i];
    if (a && a instanceof go.GraphObject) anyGraphObjects = true;
  }

  // define the click behavior
  var click =
    function(e, obj) {
      var u = obj._url;
      if (typeof u === "function") u = u(obj.findTemplateBinder());
      if (u) window.open(u, "_blank");
    };

  // define the tooltip
  var tooltip =
    go.GraphObject.make("ToolTip",
      go.GraphObject.make(go.TextBlock,
        { name: "TB", margin: 4 },
        new go.Binding("text", "", function(obj) {
          // here OBJ will be in the Adornment, need to get the HyperlinkText/TextBlock
          obj = obj.part.adornedObject;
          var u = obj._url;
          if (typeof u === "function") u = u(obj.findTemplateBinder());
          return u;
        }).ofObject()
      ),
      new go.Binding("visible", "text", function(t) { return !!t; }).ofObject("TB")
    );

  // if the text is provided, use a new TextBlock; otherwise assume the TextBlock is provided
  if (typeof (text) === "string" || typeof (text) === "function" || !anyGraphObjects) {
    if (text === null && typeof (url) === "string") text = url;
    var tb = go.GraphObject.make(go.TextBlock,
                {
                  "_url": url,
                  cursor: "pointer",
                  mouseEnter: function(e, obj) {
                    var u = obj._url;
                    if (typeof u === "function") u = u(obj.findTemplateBinder());
                    if (u) obj.isUnderline = true;
                  },
                  mouseLeave: function(e, obj) { obj.isUnderline = false; },
                  click: click,  // defined above
                  toolTip: tooltip // shared by all HyperlinkText textblocks
                }
              );
    if (typeof(text) === "string") {
      tb.text = text;
    } else if (typeof(text) === "function") {
      tb.bind(new go.Binding("text", "", text).ofObject())
    } else if (typeof (url) === "function") {
      tb.bind(new go.Binding("text", "", url).ofObject())
    }
    return tb;
  } else {
    function findTextBlock(obj) {
      if (obj instanceof go.TextBlock) return obj;
      if (obj instanceof go.Panel) {
        var it = obj.elements;
        while (it.next()) {
          var result = findTextBlock(it.value);
          if (result !== null) return result;
        }
      }
      return null;
    }
    return go.GraphObject.make(go.Panel,
      {
        "_url": url,
        cursor: "pointer",
        mouseEnter: function(e, panel) {
          var tb = findTextBlock(panel);
          var u = panel._url;
          if (typeof u === "function") u = u(panel.findTemplateBinder());
          if (tb !== null && u) tb.isUnderline = true;
        },
        mouseLeave: function(e, panel) {
          var tb = findTextBlock(panel);
          if (tb !== null) tb.isUnderline = false;
        },
        click: click,  // defined above
        toolTip: tooltip  // shared by all HyperlinkText panels
      }
    );
  }
});