How Can I use Javascript to loop through an array and change and add extra HTML that outputs some text with those values?

Question

For Example, I am using an API that returns an JSON array of values and I want to output them to the page.

Here is the full code I am working with if anyone wants to try it out to see where I can get it to work.

I have created Some HTML for the layout of the values I want to output when a button is clicked like so:

<p class="txData"> 
    <p id="txHash">Transaction ID: </p><br>
    <p id="txTime">Time: </p><br>
    <p id="txToken">Token Symbol: </p><br>
    <p id="txTo">To: </p><br>
    <p id="txFrom">From: </p><br>
    <p id="txValue">Amount Transferred: </p><br>
    <p>***********************************</p><br>
</p>

I then assign variables for those elements which I want to append to:

        let txHash = document.querySelector('#txHash');
        let txTime = document.querySelector('#txTime');
        let txToken = document.querySelector('#txToken');
        let txTo = document.querySelector('#txTo');
        let txFrom = document.querySelector('#txFrom');
        let txValue = document.querySelector('#txValue');

And I append the retrieved values from the API by doing: txHash.insertAdjacentHTML('beforeend', jsonFile.result[0].hash);

                txTime.insertAdjacentHTML('beforeend', jsonFile.result[0].timeStamp);

                txToken.insertAdjacentText('beforeend', jsonFile.result[0].tokenSymbol)

                txTo.insertAdjacentHTML('beforeend', jsonFile.result[0].to);

                txFrom.insertAdjacentHTML('beforeend', jsonFile.result[0].from);

                txValue.insertAdjacentHTML('beforeend', web3.utils.fromWei(jsonFile.result[0].value, 'ether'));

This works to output the values wanted for the first Transaction (index [0]).

How could I create a loop that would basically use the template HTML at the start but then output it for the next 5 elements in the array so that it would be the details for each new trasanction outputted in the same format, but without having to code it 5 times?

I'm new to HTML and Javascript so appreciate any help. Thank you.

Answer 1

First piece of advice, if you don't already know it, you should avoid using static id's in your html template if you plan to use it for displaying a list, because id's must be unique in a single html page.

Second one, you should use a framework to help you displaying your data as a list. If you know famous ones such as Angular or React. You can also use jQuery as someone has advised you.

Here is a little example with VueJS which allows you to define components with html templates. Then, you can use them in a loop with the for directive (please note I'm not a VueJS expert and you may find better solutions) :

<body>
    <div id="app">
      <div v-for="json in jsonFile">
        <data-display v-bind:json="json"></data-display>
      </div>
    </div>
    
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script type="text/javascript">
      
      var DataDisplay = {
        props: ['json'],
        template: '<div class="txData">\
                    <p>Transaction ID: {{json.hash}}</p>\
                    <p id="txTime">Time: {{json.timeStamp}}</p>\
                    <p id="txToken">Token Symbol: {{json.tokenSymbol}}</p>\
                    <p id="txTo">To: {{json.to}}</p>\
                    <p id="txFrom">From: {{json.from}}</p>\
                    <p id="txValue">Amount Transferred: {{json.value}}</p>\
                    <p>***********************************</p>\
                   </div>'
      };
      
      var vm = new Vue({
        el: "#app",
        data: {
          jsonFile: [
            {
              hash: 'hash1',
              timeStamp: 'timestamp1',
              tokenSymbol: 'token1',
              to: 'to1',
              from: 'from1',
              value: 'value1'
            }, {
              hash: 'hash2',
              timeStamp: 'timestamp2',
              tokenSymbol: 'token2',
              to: 'to2',
              from: 'from2',
              value: 'value2'
            }
          ]
        }, 
        components: {
          'data-display': DataDisplay
        }
      });
    </script>
  </body>

Documentation used for the example :

How Can I use Javascript to loop through an array and change and add extra HTML that outputs some text with those values?

Question

1 answers

solution1
2 2018-08-01 12:15:54

How Can I use Javascript to loop through an array and change and add extra HTML that outputs some text with those values?

Question

1 answers

solution1 2 2018-08-01 12:15:54

solution1
2 2018-08-01 12:15:54