px-vis-reference-curve.html

<!--
Copyright (c) 2018, General Electric

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.
-->

<link rel="import" href="../polymer/polymer.html"/>
<link rel="import" href="px-vis-behavior-common.html" />
<link rel="import" href="px-vis-behavior-d3.html" />
<link rel="import" href="px-vis-line-svg.html"/>
<link rel="import" href="css/px-vis-styles.html">

<!--

### Usage

    <px-vis-reference-curve
        svg="[[svg]]"
        x="[[x]]"
        y="[[y]]"
        axis-color="[[axisColor]]"
        tick-values="[[drawnTickValues]]"
        dimensions="[[dimensions]]"
        margin="[[margin]]"
        domain-changed="[[domainChanged]]">
    </px-vis-reference-curve>

### Styling
The following custom properties are available for styling:

Custom property | Description
:----------------|:-------------
`--px-vis-reference-curve-default-color`  |  default color for the reference curve


@element px-vis-reference-curve
An element which draws polygonal grid lines.
@homepage index.html
@demo demo.html
-->

<dom-module id="px-vis-reference-curve">
  <template>
    <style include="px-vis-styles"></style>
    <template is="dom-repeat" items="[[_seriesKeys]]">
      <px-vis-line-svg
        svg="[[_refCurveG]]"
        id-prefix="[[_idPrefix]]"
        series-id="[[item]]"
        chart-data="[[_referenceData]]"
        complete-series-config="[[_referenceConfig]]"
        x="[[x]]"
        y="[[_returnYScale(item, _referenceConfig, domainChanged)]]"
        domain-changed="[[domainChanged]]"
        stroke-width="[[_returnStrokeWidth(item, _referenceConfig)]]"
        clip-path="[[clipPath]]"
        interpolation-function="[[_returnInterpolation(item, _referenceConfig)]]">
      </px-vis-line-svg>
    </template>
  </template>
</dom-module>

<script>
  Polymer({
    is: 'px-vis-reference-curve',

    behaviors: [
      PxVisBehavior.observerCheck,
      PxVisBehaviorD3.svg,
      PxVisBehaviorD3.axes,
      PxVisBehavior.commonMethods,
      PxVisBehaviorD3.clipPath,
      PxVisBehavior.updateStylesOverride,
      PxVisBehavior.referenceCurveProps,
      PxVisBehavior.scaleTypeCheck
    ],

    /**
     * Properties block, expose attribute values to the DOM via 'reflect'
     *
     * @property properties
     * @type Object
     */
    properties: {
      _referenceConfig: {
        type: Object,
        notify: true
      },
      _seriesKeys: Array,
      _refCurveG: Object,
      _textBuilder: Object,
      _textNodes: Object,
      _referenceData: {
        type: Array,
        computed: '_createReferenceData(referenceData.*, reverseData)'
      },
      reverseData: {
        type: Boolean,
        value: false
      },
      chartId: {
        type: String,
        value: ''
      },
      _idPrefix: {
        type: String,
        computed: '_computeIdPrefix(chartId)'
      }
    },

    observers: [
      '_createRefCurveG(svg, domainChanged)',
      '_buildReferenceConfig(referenceConfig.*)',
      '_drawText(_referenceConfig.*, _refCurveG)'
    ],

    _createReferenceData: function() {
      if(!this.referenceData) {
        return;
      }

      var d = JSON.parse(JSON.stringify(this.referenceData));
      if(this.reverseData) {
        d.reverse();
      }

      return d;
    },

    _createRefCurveG: function() {
      if(this._isD3Empty(this.svg) || !this.domainChanged) {
        return;
      }

      if(this._isD3Empty(this._refCurveG)) {
        const g = this.svg.append('g')
          .attr('class', 'reference-curves');

        this.set('_refCurveG', g);
      }
    },

    _buildReferenceConfig: function() {
      if(!this.referenceConfig) {
        return;
      }

      var keys = Object.keys(this.referenceConfig),
          config = {};


      keys.forEach(function(k) {
        if(!this.referenceConfig[k]) {
          return;
        }

        config[k] = {};

        config[k]['x'] = this.referenceConfig[k]['x'] ? this.referenceConfig[k]['x'] : 'x';
        config[k]['y'] = this.referenceConfig[k]['y'] ? this.referenceConfig[k]['y'] : 'y';
        config[k]['interpolationFunction'] = this.referenceConfig[k]['interpolationFunction'] ? this.referenceConfig[k]['interpolationFunction'] : Px.d3.curveCardinal;
        config[k]['color'] = this.referenceConfig[k]['color'] ? this.referenceConfig[k]['color'] : this._checkThemeVariable("--px-vis-reference-curve-default-color", 'rgb(0,0,0)');
        config[k]['strokeWidth'] = this.referenceConfig[k]['strokeWidth'] ? this.referenceConfig[k]['strokeWidth'] : 1;
        config[k]['axis'] = this.referenceConfig[k]['axis'] ? this.referenceConfig[k]['axis'] : { "id": "defaultAxis" };
        config[k]['name'] = this.referenceConfig[k]['name'] ? this.referenceConfig[k]['name'] : null;
      }.bind(this));

      this.set('_seriesKeys', keys);
      this.set('_referenceConfig', config);
    },

    _drawText: function() {
      if(this._isD3Empty(this._refCurveG) || this._isObjEmpty(this._referenceConfig)) {
        return;
      }

      var _this = this;

      this._textBuilder = this._refCurveG.selectAll('text.reference-curve-name')
        .data(this._seriesKeys);

      this._textBuilder.enter()
        .append('text')
        .style('font-family',this._checkThemeVariable("--px-vis-font-family", 'Comic Sans MS'))
        .attr('font-style', this._checkThemeVariable("--px-vis-font-family", 'Comic Sans MS'))
        .attr('font-size', '12px')
        .each(function(d,i) {
          _this._enterText.bind(_this)(d, i, this);
        })
      .merge(this._textBuilder)
        .attr('fill', function(d) { return this.referenceConfig[d]['color']; }.bind(this))
        .each(function(d,i) {
          _this._mergeText.bind(_this)(d, i, this);
        });

      this._textNodes = this._refCurveG.selectAll('text.reference-curve-name');

    },

    _enterText: function(d, i, elem) {
      Px.d3.select(elem).append('textPath')
        .attr('class', 'reference-curve')
        .attr('startOffset', 5)
        .attr('alignment-baseline', 'after-edge');
    },

    _mergeText: function(d, i, elem) {
      Px.d3.select(elem).select('textPath.reference-curve')
        .attr("xlink:href", function(d) { return '#refCurve_' + this.chartId + d; }.bind(this))
        .text(function(d) { return this.referenceConfig[d]['name']; }.bind(this));
    },

    /**
     * Helper function to return a d3 interpolation function.
     *
     * @method _returnInterpolation
     */
    _returnInterpolation: function(item) {
      if(this.hasUndefinedArguments(arguments)) {
        return;
      }

      return this._referenceConfig[item]['interpolationFunction'];
    },

    _returnStrokeWidth: function(item) {
      if(this.hasUndefinedArguments(arguments)) {
        return;
      }

      return this._referenceConfig[item]['strokeWidth'];
    },

    _returnYScale: function(seriesId, config) {
      if(this.domainChanged) {
        if(typeof this.y === 'object') {
          var d = config[seriesId]['axis']['id'];
          if(this.y && this.y[d]) {
            return this.y[d];
          }
        } else if(typeof this.y === 'function') {
          return this.y;
        }
      }
      return;
    },

    _computeIdPrefix: function() {
      return 'refCurve_' + this.chartId;
    }
  });
</script>