155 lines
3.9 KiB
Markdown
155 lines
3.9 KiB
Markdown
---
|
|
id: 587d7faa367417b2b2512bd2
|
|
title: Add Labels to D3 Elements
|
|
challengeType: 6
|
|
forumTopicId: 301476
|
|
dashedName: add-labels-to-d3-elements
|
|
---
|
|
|
|
# --description--
|
|
|
|
D3 lets you label a graph element, such as a bar, using the SVG `text` element.
|
|
|
|
Like the `rect` element, a `text` element needs to have `x` and `y` attributes, to place it on the SVG canvas. It also needs to access the data to display those values.
|
|
|
|
D3 gives you a high level of control over how you label your bars.
|
|
|
|
# --instructions--
|
|
|
|
The code in the editor already binds the data to each new `text` element. First, append `text` nodes to the `svg`. Next, add attributes for the `x` and `y` coordinates. They should be calculated the same way as the `rect` ones, except the `y` value for the `text` should make the label sit 3 units higher than the bar. Finally, use the D3 `text()` method to set the label equal to the data point value.
|
|
|
|
**Note**
|
|
For the label to sit higher than the bar, decide if the `y` value for the `text` should be 3 greater or 3 less than the `y` value for the bar.
|
|
|
|
# --hints--
|
|
|
|
The first `text` element should have a label of 12 and a `y` value of 61.
|
|
|
|
```js
|
|
assert($('text').eq(0).text() == '12' && $('text').eq(0).attr('y') == '61');
|
|
```
|
|
|
|
The second `text` element should have a label of 31 and a `y` value of 4.
|
|
|
|
```js
|
|
assert($('text').eq(1).text() == '31' && $('text').eq(1).attr('y') == '4');
|
|
```
|
|
|
|
The third `text` element should have a label of 22 and a `y` value of 31.
|
|
|
|
```js
|
|
assert($('text').eq(2).text() == '22' && $('text').eq(2).attr('y') == '31');
|
|
```
|
|
|
|
The fourth `text` element should have a label of 17 and a `y` value of 46.
|
|
|
|
```js
|
|
assert($('text').eq(3).text() == '17' && $('text').eq(3).attr('y') == '46');
|
|
```
|
|
|
|
The fifth `text` element should have a label of 25 and a `y` value of 22.
|
|
|
|
```js
|
|
assert($('text').eq(4).text() == '25' && $('text').eq(4).attr('y') == '22');
|
|
```
|
|
|
|
The sixth `text` element should have a label of 18 and a `y` value of 43.
|
|
|
|
```js
|
|
assert($('text').eq(5).text() == '18' && $('text').eq(5).attr('y') == '43');
|
|
```
|
|
|
|
The seventh `text` element should have a label of 29 and a `y` value of 10.
|
|
|
|
```js
|
|
assert($('text').eq(6).text() == '29' && $('text').eq(6).attr('y') == '10');
|
|
```
|
|
|
|
The eighth `text` element should have a label of 14 and a `y` value of 55.
|
|
|
|
```js
|
|
assert($('text').eq(7).text() == '14' && $('text').eq(7).attr('y') == '55');
|
|
```
|
|
|
|
The ninth `text` element should have a label of 9 and a `y` value of 70.
|
|
|
|
```js
|
|
assert($('text').eq(8).text() == '9' && $('text').eq(8).attr('y') == '70');
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --seed-contents--
|
|
|
|
```html
|
|
<body>
|
|
<script>
|
|
const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
|
|
|
|
const w = 500;
|
|
const h = 100;
|
|
|
|
const svg = d3.select("body")
|
|
.append("svg")
|
|
.attr("width", w)
|
|
.attr("height", h);
|
|
|
|
svg.selectAll("rect")
|
|
.data(dataset)
|
|
.enter()
|
|
.append("rect")
|
|
.attr("x", (d, i) => i * 30)
|
|
.attr("y", (d, i) => h - 3 * d)
|
|
.attr("width", 25)
|
|
.attr("height", (d, i) => 3 * d)
|
|
.attr("fill", "navy");
|
|
|
|
svg.selectAll("text")
|
|
.data(dataset)
|
|
.enter()
|
|
// Add your code below this line
|
|
|
|
|
|
|
|
|
|
// Add your code above this line
|
|
</script>
|
|
<body>
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```html
|
|
<body>
|
|
<script>
|
|
const dataset = [12, 31, 22, 17, 25, 18, 29, 14, 9];
|
|
|
|
const w = 500;
|
|
const h = 100;
|
|
|
|
const svg = d3.select("body")
|
|
.append("svg")
|
|
.attr("width", w)
|
|
.attr("height", h);
|
|
|
|
svg.selectAll("rect")
|
|
.data(dataset)
|
|
.enter()
|
|
.append("rect")
|
|
.attr("x", (d, i) => i * 30)
|
|
.attr("y", (d, i) => h - 3 * d)
|
|
.attr("width", 25)
|
|
.attr("height", (d, i) => 3 * d)
|
|
.attr("fill", "navy");
|
|
|
|
svg.selectAll("text")
|
|
.data(dataset)
|
|
.enter()
|
|
.append("text")
|
|
.attr("x", (d, i) => i * 30)
|
|
.attr("y", (d, i) => h - (3 * d) - 3)
|
|
.text((d) => d)
|
|
</script>
|
|
<body>
|
|
```
|