Files
Nicholas Carrigan (he/him) b36cdbafd1 chore: rename "part" to "step" (#43934)
* chore: rename part to step

* chore: update metas

* chore: more renaming

* chore: update tooling

* chore: update frontmatter

* chore(tools): title testing
2021-10-21 18:07:52 +01:00

6.5 KiB

id, title, challengeType, dashedName
id title challengeType dashedName
5d8a4cfbe6b6180ed9a1ca1d Step 64 0 step-64

--description--

Next, chain the enter() function to the selection.

The enter function identifies elements that need to be added when the data array is longer than the selection array. This is why you wanted the selectAll to be an empty array before.

In this case, the twitter-circles selection has a length of 0, and the data array has a length of 9. So nine elements will be added when you use append in the next step.

--hints--

test-text

assert(/\.data\(data\)\s*\.enter\s*\(\s*\)/g.test(code));

--seed--

--before-user-code--

<!DOCTYPE html>
<html>
  <head>
    <title>D3 Dashboard</title>
    <style>
      body {
        background-color: #ccc;
        padding: 100px 10px;
      }

      .dashboard {
        width: 980px;
        height: 500px;
        background-color: white;
        box-shadow: 5px 5px 5px 5px #888;
        margin: auto;
        display: flex;
        align-items: center;
      }
    </style>
  </head>

  <body>
    <div class="dashboard"></div>
  </body>
</html>

--seed-contents--

<script>
  const data = [ 
    { year: 2012, followers: { twitter: 2594, tumblr:  401, instagram:   83 }},
    { year: 2013, followers: { twitter: 3049, tumblr:  440, instagram:  192 }},
    { year: 2014, followers: { twitter: 3511, tumblr:  415, instagram:  511 }},
    { year: 2015, followers: { twitter: 3619, tumblr:  492, instagram: 1014 }},
    { year: 2016, followers: { twitter: 4046, tumblr:  543, instagram: 2066 }},
    { year: 2017, followers: { twitter: 3991, tumblr:  701, instagram: 3032 }},
    { year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
    { year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
    { year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
  ];
</script>
<script>
  const svgMargin = 70,
    svgWidth = 700,
    svgHeight = 500,
    twitterColor = '#7cd9d1',
    tumblrColor = '#f6dd71',
    instagramColor = '#fd9b98';

  const lineGraph = d3.select('.dashboard')
    .append('svg')
    .attr('width', svgWidth)
    .attr('height', svgHeight);

  const yScale = d3.scaleLinear()
    .domain([0, 5000])
    .range([svgHeight - svgMargin, svgMargin]);

  const xScale = d3.scaleLinear()
    .domain([2012, 2020])
    .range([svgMargin, svgWidth - svgMargin]);

  const yAxis = d3.axisLeft(yScale)
    .ticks(6, '~s');

  const xAxis = d3.axisBottom(xScale)
    .tickFormat(d3.format(''))
    .tickPadding(10);

  lineGraph.append('g')
    .call(yAxis)
    .attr('transform', `translate(${svgMargin}, 0)`)
    .style('font', '10px verdana');

  lineGraph.append('g')
    .call(xAxis)
    .attr('transform', `translate(0, ${svgHeight - svgMargin})`)
    .selectAll('text')
    .style('transform', 'translate(-12px, 0) rotate(-50deg)')
    .style('text-anchor', 'end')
    .style('cursor', 'pointer')
    .style('font', '10px verdana')

  const twitterLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.twitter));

  lineGraph.append('path')
    .attr('d', twitterLine(data))
    .attr('stroke', twitterColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const tumblrLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.tumblr));

  lineGraph.append('path')
    .attr('d', tumblrLine(data))
    .attr('stroke', tumblrColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const instagramLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.instagram));

  lineGraph.append('path')
    .attr('d', instagramLine(data))
    .attr('stroke', instagramColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');
    
  lineGraph.selectAll('twitter-circles')
    .data(data)



</script> 

--solutions--

<script>
  const data = [ 
    { year: 2012, followers: { twitter: 2594, tumblr:  401, instagram:   83 }},
    { year: 2013, followers: { twitter: 3049, tumblr:  440, instagram:  192 }},
    { year: 2014, followers: { twitter: 3511, tumblr:  415, instagram:  511 }},
    { year: 2015, followers: { twitter: 3619, tumblr:  492, instagram: 1014 }},
    { year: 2016, followers: { twitter: 4046, tumblr:  543, instagram: 2066 }},
    { year: 2017, followers: { twitter: 3991, tumblr:  701, instagram: 3032 }},
    { year: 2018, followers: { twitter: 3512, tumblr: 1522, instagram: 4512 }},
    { year: 2019, followers: { twitter: 3274, tumblr: 1989, instagram: 4715 }},
    { year: 2020, followers: { twitter: 2845, tumblr: 2040, instagram: 4801 }}
  ];
</script>
<script>
  const svgMargin = 70,
    svgWidth = 700,
    svgHeight = 500,
    twitterColor = '#7cd9d1',
    tumblrColor = '#f6dd71',
    instagramColor = '#fd9b98';

  const lineGraph = d3.select('.dashboard')
    .append('svg')
    .attr('width', svgWidth)
    .attr('height', svgHeight);

  const yScale = d3.scaleLinear()
    .domain([0, 5000])
    .range([svgHeight - svgMargin, svgMargin]);

  const xScale = d3.scaleLinear()
    .domain([2012, 2020])
    .range([svgMargin, svgWidth - svgMargin]);

  const yAxis = d3.axisLeft(yScale)
    .ticks(6, '~s');

  const xAxis = d3.axisBottom(xScale)
    .tickFormat(d3.format(''))
    .tickPadding(10);

  lineGraph.append('g')
    .call(yAxis)
    .attr('transform', `translate(${svgMargin}, 0)`)
    .style('font', '10px verdana');

  lineGraph.append('g')
    .call(xAxis)
    .attr('transform', `translate(0, ${svgHeight - svgMargin})`)
    .selectAll('text')
    .style('transform', 'translate(-12px, 0) rotate(-50deg)')
    .style('text-anchor', 'end')
    .style('cursor', 'pointer')
    .style('font', '10px verdana')

  const twitterLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.twitter));

  lineGraph.append('path')
    .attr('d', twitterLine(data))
    .attr('stroke', twitterColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const tumblrLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.tumblr));

  lineGraph.append('path')
    .attr('d', tumblrLine(data))
    .attr('stroke', tumblrColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');

  const instagramLine = d3.line()
    .x(d => xScale(d.year))
    .y(d => yScale(d.followers.instagram));

  lineGraph.append('path')
    .attr('d', instagramLine(data))
    .attr('stroke', instagramColor)
    .attr('stroke-width', 3)
    .attr('fill', 'transparent');
    
  lineGraph.selectAll('twitter-circles')  
    .data(data)
    .enter()

  

</script>