jQuery keep show hide state based on select option

问题:

I have drop down select and show hide other fields (within divs) based on option selected in the dropdown list.

This code works fine and show hide based on selection but when I load the page all fields are visible.

Other thing is for instance if I want to show fields if option 2 selected and save the option to the database and when reload the page it is not saving the show hide state based on the option selected.

HTML

<select id="row1_layout_options" name="row1_layout_options">
    <option value="Select Layout Type">Select Layout Type</option>
    <option value="layout_type1">layout_type1</option>
    <option value="layout_type2">layout_type2</option>
    <option value="layout_type3">layout_type3</option>
    <option value="layout_type4">layout_type4</option>
    <option value="layout_type5">layout_type5</option>
    <option value="layout_type6">layout_type6</option>
    <option value="layout_type7">layout_type7</option>
    <option value="layout_type8">layout_type8</option>
</select>

<div id="row1_col1_layout_type2">
    <input type="text" class="qa-form-tall-text" value="" name="q2am_fp_row1_col1_layout_type2">
</div>

Jquery

$('#row1_layout_options').change(function() {
   $('#row1_col1_layout_type1, #row1_col1_layout_type2, #row1_col1_layout_type3').hide();
   $('#row1_col1_' + $(this).val()).show();
});

So how can I write script where all fields are hidden on page load but it will keep show hide state based on selected option.

回答1:

Assign an common class to all the div's that holds the content

show hide based on selection but when I load the page all fields are visible

<div id="row1_col1_layout_type2" class="content">
                                        ^
                                        ----- This to target with a single selector

CSS

.content{
   display :none;
}

And in the JS just trigger the change event so as to show the div with option that is selected

$('#row1_layout_options').change(function() {
   $('.content').hide();
   $('#row1_col1_' + $(this).val()).show();
   // Sen d an ajax request to save the value in DB
   $.ajax({

   });
}).change();  <--- Trigger the event

Next is the Page Reload. Web is stateless . So it will not remember the previous state. The only thing you can do is persist the value after page refresh. Maybe in as a cookie, Local Storage or saving it on server and retrieving it back.. Check Fiddle

回答2:

Just do the same in document.ready

$(document).ready(function(){
    $('#row1_col1_layout_type1, #row1_col1_layout_type2, #row1_col1_layout_type3').hide();
    $('#row1_col1_' + $('#row1_layout_options').val()).show();

    $('#row1_layout_options').on('change',function() {
       $('#row1_col1_layout_type1, #row1_col1_layout_type2, #row1_col1_layout_type3').hide();
       $('#row1_col1_' + $(this).val()).show();
    });
});

here is the fiddle

回答3:

I would suggest adding a class for your loaded content which will make them hidden.

HTML

<select id="row1_layout_options" name="row1_layout_options">
    <option value="Select Layout Type">Select Layout Type</option>
    <option value="layout_type1">layout_type1</option>
    <option value="layout_type2">layout_type2</option>
    <option value="layout_type3">layout_type3</option>
    <option value="layout_type4">layout_type4</option>
    <option value="layout_type5">layout_type5</option>
    <option value="layout_type6">layout_type6</option>
    <option value="layout_type7">layout_type7</option>
    <option value="layout_type8">layout_type8</option>
</select>

<div id="layouts">
    <div id="row1_col1_layout_type2">
        <input type="text" class="qa-form-tall-text" value="" name="q2am_fp_row1_col1_layout_type2">
    </div>
</div>

JS

$('#row1_layout_options').change(function() {
   $('#layouts>div.selected').removeClass('selected');
   $('#row1_col1_' + $(this).val()).addClass('selected');
});

CSS

#layouts>div{
    display:none;
}

#layouts>div.selected{
    display:block;
}

EDIT : Saving selected

As for saving the selected option you have these non exhaustive list of solution :

• HTML5 localstorage, you can use localStorage which is a javascript accessible store that is flushed like cookies. I wouldn't recommend that one I found it very much unreliable.
• Server side persistence. Basically when you set an option as selected you send a query to a webservice that will save the state somewhere (DB, object instance etc...)
• URL modification. that's not really a persistence solution but it could match the need sometimes. You can retrieve a value in the URL parameter section like http://localhost/mysite?selectedId=2. This way you can have the information directly within the link. Easier to share the state.