Sequential lists using v-for-CodePudding

I have an object that contains pairs of data that I would like to display based on category. I believe this has to do with nested v-for loops, but I'm having trouble figuring out the right way to go about this.

 categoryArray = {stage 1, red}, {stage 1, blue}, {stage 2, orange}, {stage 3, brown}, {stage 2, green}

Desired display: Stage 1: red, blue Stage 2: orange Stage 3: brown

I do not have workable code yet. My strategy has been to create an array of unique Stages, use that to display the Stages, but I can't figure out how to iterate the items within the stages.

Getting the stages:

let stagesArray = [];
      categoryArray.value.forEach((entry, index) => {
        stagesArray.push(entry.stageNumber);
      });
      //creating array of unique stages

      uniqueRooms.value = [...new Set(stagesArray)];
    })

The above works to get the unique array of rooms.

<template>
   <div v-for="(stage, index) in uniqueRooms" :key="index">
       {{ room }}
      <div v-for="(color, index) in filterStages" :key="index">
         {{ color }} 
      </div>
   </div>
</template>
<script>

//this is a mess and I don't know where to go.
const filterStages = computed(function (stage) {
  return stagesUnique.value.forEach((stageNumber) => {
    return categoriesArray.value.filter((color) => color.stage     
    === stageNumber);
    
  });
 </script>

I am out over my skiis. I just need some leads on how to loop through the main category(stage), with unique values, and then display all matching colors within that category.

This seems very close, but I can't figure out the way to get unique stages from this. Nested loop in Vue

CodePudding user response：

You have the same index for both loops, so it's wrong

   <div v-for="(stage, index) in uniqueRooms" :key="index">
                                                     ----
       {{ room }}
      <div v-for="(color, index) in filterStages" :key="index">
                                                        -----

CodePudding user response：

Is this what you're looking for?

const { createApp, computed } = Vue;

createApp({
  setup() {
    const data = [
      { stage: 1, color: 'red' },
      { stage: 1, color: 'blue' },
      { stage: 2, color: 'orange' },
      { stage: 3, color: 'brown' },
      { stage: 2, color: 'green' }
    ];
    const stages = computed(
      () => [...new Set(data.map(({ stage }) => stage))]
    );
    const stageColors = computed(
      () => s => data.filter(({ stage }) => stage === s)
                     .map(({ color }) => color)
    );
    return {
      stages,
      stageColors
    }
  }
}).mount('#app');

h4 { margin-bottom: 0;}

<script src="https://unpkg.com/vue@next/dist/vue.global.prod.js"></script>
<div id="app">
  <div v-for="stage in stages" :key="stage">
    <h4>Stage #{{ stage }}</h4>
    <ul>
      <li v-for="color in stageColors(stage)" :key="color" v-text="color" />
    </ul>
    <hr>
  </div>
</div>