Selected Value not showing in Textfield Select - Material UI React Component

Question

I have TextField Select Material UI components based on a certain number of value in a variable.

{this.state.selectedNextHops.map((nextHop, index) => (
              <div>
                <TextField
                    select
                    className="vnfprofile-field"
                    InputProps={{ className: 'variable-value site-details-view-textfield' }}
                    InputLabelProps={{ shrink: true }}
                    SelectProps={{
                        MenuProps: {
                            className: 'vnf-designer-value',
                            getContentAnchorEl: null,
                            anchorOrigin: {
                                vertical: 'bottom',
                                horizontal: 'left',
                            }
                        },
                    }}
                    value = {this.state.selectedNextHops[index] || ''}
                    disabled={this.props.newPopoverPanelView === 'VIEW' ? true : false}
                    onChange={(e) => this.handleChange('nexthop', e)}
                  >
                    {this.state.remainingNextHops.length !== 0 ? this.state.remainingNextHops.map((option, i) => (
                        <MenuItem key ={i} value = {option || ''}>
                          {option}
                        </MenuItem>
                      )) :
                        <MenuItem value = {'No Data Available'}>
                            {'No Data Available'}
                        </MenuItem>}
                  </TextField>
                  <TextField
                    className="vnfprofile-field subnet-textfield"
                    InputProps={{ className: 'variable-value' }}
                    InputLabelProps={{ shrink: true }}
                    value = {'29'}
                  />
                </div>
                ))
          }

The TextFields show up sequentially when I select value from the previous dropdown and filters the menu based on previous selection.

if(selectedNextHops.indexOf(event.target.value) === -1) {
            selectedNextHops.push(event.target.value);
        }
        remainingNextHops = this.props.nextHopSapds.filter(nextHop => selectedNextHops.indexOf(nextHop) === -1);

this.setState({
            selectedNextHops: selectedNextHops,
            remainingNextHops: remainingNextHops
        });

Update: Here is my handleChange Method ->

handleChange(type, event) {
    let selectedNextHops = JSON.parse(JSON.stringify(this.state.selectedNextHops));
    let remainingNextHops = [];
    if(type === 'nexthop') {
        selectedNextHops = selectedNextHops.filter(nh => nh !== '');
        isContentChanged = true;
        if(selectedNextHops.indexOf(event.target.value) === -1) {
            selectedNextHops.push(event.target.value);
        }
        remainingNextHops = this.props.nextHopSapds.filter(nextHop => selectedNextHops.indexOf(nextHop) === -1);
        if(remainingNextHops.length !== 0) {
            selectedNextHops.push('');
        }
        this.setState({
            selectedNextHops: selectedNextHops,
            remainingNextHops: remainingNextHops
        });
    }
  }

The state is updating fine, but the textfield does not display the selected value. I have tried everything I knew. Any help is appreciated.

Answer 1

This is hard to debug without seeing a working snippet or the state ( especially this.state.selectedNextHops) , but based on the code sandbox provided ( in the comment ) , I assume it's the same problem, so this answer will apply to the sandbox code :

this.setState({
  selectedID: event.target.value.id,
  visibleValue: event.target.value.name
});

event.target.value.id and event.target.value.name are undefined,

console.log(console.log(event.target)) // {value: "S0002", name: undefined}

For the select to display a selected option, the value attribute for both need to match :

<select value="2">
        ^^^^^^^^^
  <option value="1">first value</option>
  <option value="2">second value</option>
          ^^^^^^^^^ 
</select>

in the example in the code sandbox, the value of the Select is value={this.state.visibleValue} and the values of the options are value={x.label}

Since this.state.visibleValue is always undefined, you'll never see the value of the select update.

A quick fix for this is to change the handleChage function to :

handleChangeTest = event => {
  this.setState({
    selectedID: event.target.id,
    visibleValue: event.target.value
  });
};

but that will leave selectedID undefined , to set it, add the attribute id={x.id} to the option and use event.currentTarget to get its value :

{this.state.data.map(x => (
  <MenuItem key={x.id} value={x.label} id={x.id}>
                                      ^^^^^^^^^
    {x.name}
  </MenuItem>
))}

And

handleChangeTest = event => {    
  this.setState({
    selectedID: event.currentTarget.id,
                ^^^^^^^^^^^^^^^^^^^^^^
    visibleValue: event.target.value
  });
};

Working SandBox