maxGraph/packages/html/stories/FileIO.stories.js

/*
Copyright 2021-present The maxGraph project Contributors
Copyright (c) 2006-2020, JGraph Ltd

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import { Graph, constants } from '@maxgraph/core';

import { globalTypes } from '../.storybook/preview';
import { clone } from '@maxgraph/core/util/cloneUtils';
import { button } from '@maxgraph/core/util/domHelpers';
import { load } from '@maxgraph/core/util/MaxXmlRequest';

export default {
  title: 'Xml_Json/FileIO',
  argTypes: {
    ...globalTypes,
  },
};

const Template = ({ label, ...args }) => {
  const div = document.createElement('div');

  const container = document.createElement('div');
  container.style.position = 'relative';
  container.style.overflow = 'hidden';
  container.style.width = `${args.width}px`;
  container.style.height = `${args.height}px`;
  container.style.background = 'url(/images/grid.gif)';
  container.style.cursor = 'default';
  div.appendChild(container);

  // Program starts here. Creates a sample graph in the
  // DOM node with the specified ID. This function is invoked
  // from the onLoad event handler of the document (see below).
  function main(container) {
    // Checks if browser is supported
    if (!Client.isBrowserSupported()) {
      // Displays an error message if the browser is
      // not supported.
      alert('Browser is not supported!', 200, false);
    } else {
      // Creates the graph inside the given container
      const graph = new Graph(container);

      graph.setEnabled(false);
      graph.setPanning(true);
      graph.setTooltips(true);
      graph.getPlugin('PanningHandler').useLeftButtonForPanning = true;

      // Adds a highlight on the cell under the mousepointer
      new CellTracker(graph);

      // Changes the default vertex style in-place
      let style = graph.getStylesheet().getDefaultVertexStyle();
      style.shape = constants.SHAPE.ROUNDED;
      style.perimiter = Perimeter.RectanglePerimeter;
      style.gradientColor = 'white';
      style.perimeterSpacing = 4;
      style.shadow = true;

      style = graph.getStylesheet().getDefaultEdgeStyle();
      style.labelBackgroundColor = 'white';

      style = clone(style);
      style.startArrow = constants.ARROW.CLASSIC;
      graph.getStylesheet().putCellStyle('2way', style);

      graph.isHtmlLabel = function (cell) {
        return true;
      };

      // Larger grid size yields cleaner layout result
      graph.gridSize = 20;

      // Creates a layout algorithm to be used
      // with the graph
      const layout = new MxFastOrganicLayout(graph);

      // Moves stuff wider apart than usual
      layout.forceConstant = 140;

      // Adds a button to execute the layout
      this.el2.appendChild(
        button('Arrange', function (evt) {
          const parent = graph.getDefaultParent();
          layout.execute(parent);
        })
      );

      // Load cells and layouts the graph
      graph.batchUpdate(() => {
        // Loads the custom file format (TXT file)
        parse(graph, 'fileio.txt');

        // Loads the Graph file format (XML file)
        // read(graph, 'fileio.xml');

        // Gets the default parent for inserting new cells. This
        // is normally the first child of the root (ie. layer 0).
        const parent = graph.getDefaultParent();

        // Executes the layout
        layout.execute(parent);
      });

      graph.dblClick = function (evt, cell) {
        const mxe = new EventObject(InternalEvent.DOUBLE_CLICK, { event: evt, cell });
        this.fireEvent(mxe);

        if (
          this.isEnabled() &&
          !InternalEvent.isConsumed(evt) &&
          !mxe.isConsumed() &&
          cell != null
        ) {
          alert(`Show properties for cell ${cell.customId || cell.getId()}`);
        }
      };
    }
  }

  // Custom parser for simple file format
  function parse(graph, filename) {
    const model = graph.getDataModel();

    // Gets the default parent for inserting new cells. This
    // is normally the first child of the root (ie. layer 0).
    const parent = graph.getDefaultParent();

    const req = load(filename);
    const text = req.getText();

    const lines = text.split('\n');

    // Creates the lookup table for the vertices
    const vertices = [];

    // Parses all lines (vertices must be first in the file)
    graph.batchUpdate(() => {
      for (let i = 0; i < lines.length; i++) {
        // Ignores comments (starting with #)
        const colon = lines[i].indexOf(':');

        if (lines[i].substring(0, 1) != '#' || colon == -1) {
          const comma = lines[i].indexOf(',');
          const value = lines[i].substring(colon + 2, lines[i].length);

          if (comma == -1 || comma > colon) {
            const key = lines[i].substring(0, colon);

            if (key.length > 0) {
              vertices[key] = graph.insertVertex(parent, null, value, 0, 0, 80, 70);
            }
          } else if (comma < colon) {
            // Looks up the vertices in the lookup table
            const source = vertices[lines[i].substring(0, comma)];
            const target = vertices[lines[i].substring(comma + 1, colon)];

            if (source != null && target != null) {
              const e = graph.insertEdge(parent, null, value, source, target);

              // Uses the special 2-way style for 2-way labels
              if (value.indexOf('2-Way') >= 0) {
                e.style = '2way';
              }
            }
          }
        }
      }
    });
  }

  // Parses the Graph XML file format
  function read(graph, filename) {
    const req = load(filename);
    const root = req.getDocumentElement();
    const dec = new Codec(root.ownerDocument);

    dec.decode(root, graph.getDataModel());
  }

  return div;
};

export const Default = Template.bind({});