javascript - Dropdown automatically selected a value -

-

i need problem. want make dynamically dropdown , when select value 1 dropdown "a", dropdown set "b".

i have javascript function dynamically dropdown this. 

<script type="text/javascript"> function coba(){         document.getelementbyid("add").innerhtml +=   " <inputclass='department_name' type='text'     size='50' />";   }  </script>

reference: how dynamically change item of 2 related combobox

in short:

  1. in file1.php, retrieve mysql tbl1 , display in combo box a.
  2. on change of combo box a, fetch value of option , pass php file file2.php via ajax , display output in file1.php produced file2.php.
  3. in file2.php, retrieve mysql tbl2 id passed ajax , generate combo box b.

example:

index.php

<script type="text/javascript"> function getxmlhttpobject() {     if (window.xmlhttprequest)     {         return new xmlhttprequest();     }     if (window.activexobject)     {         return new activexobject("microsoft.xmlhttp");     }        return null; }  function ajax_function(url, postdata, id) {     xmlhttp=getxmlhttpobject();     xmlhttp.open("post", url, true);     xmlhttp.setrequestheader("content-type", "application/x-www-form-urlencoded");     xmlhttp.setrequestheader("content-length", postdata.length);     xmlhttp.setrequestheader("connection", "close");     xmlhttp.onreadystatechange=function()     {         if(xmlhttp.readystate==4)         {             document.getelementbyid(id).innerhtml=xmlhttp.responsetext;                                     }            }                         xmlhttp.send(postdata); }  function dispsecond(id) {     var params  = 'id=' + id ;     var divid = 'dispdiv';     ajax_function('ajax_display.php', params, divid); }  </script>  <?php /* mysqli query retrieve , store in $arraylist(id=>text)    example:  $arraylist = array(1=>'ford',2=>'chevy'); */ ?>  <select id="drop_first" name="drop_first" onchange="return dispsecond(this.value);"> <option value="0">[select]</option> <?php foreach ($arraylist $k=>$v) { echo '<option value="'.$k.'">'.$v.'</option>';   } ?> </select>  <div id="dispdiv"></div>

ajax_display.php

<?php $id     = isset($_request['id']) ? $_request['id'] : ''; if ($id) { /* mysqli query retrieve , store in $subarray $id    example:      if $id=1     $subarray = array(1=>'focus',2=>'explorer');    if $id=2    $subarray = array(1=>'cavalier',2=>'impala', 3=>'malibu'); */ ?>     <select id="drop_second" name="drop_second">     <option value="0">[select]</option>     <?php     foreach ($subarray $k=>$v)     {     echo '<option value="'.$k.'">'.$v.'</option>';       }     ?>     </select> <?php } ?>

note:

use mysqli or pdo instead mysql

below demo , download based on arrays, can implement using mysqli retrieval.

also can try using $.ajax more easy also.

demo | download


Comments

Post a Comment

Popular posts from this blog

ios - Memory not freeing up after popping viewcontroller using ARC -

-
hi project arc based, using uinavigationcontroller make transition between viewcontroller. using profiler analyse happening behind scene memory. noticed when push viewcontroller allocate memory components , when pop not freeing allocated memory. since using arc unable implement dealloc or release component. have analysed in detail , there no memory leak in project. i not using strong property push viewcontroller. here how pushing viewcontroller. viewcontroller *obj = [[viewcontroller alloc] init]; [self.navigationcontroller pushviewcontroller:obj animated:no]; any clue whats going on? should free memory have consumed. please advise your description indicates have retain cycle, leads objects not being deallocated. typical source of retain cycles properties assigned loading nib files (usually declared iboutlet ). two strategies break them , release objects: declare property weak : @property (nonatomic, weak) iboutlet uilabel *statuslabel; set property nil in...
Read more

Django REST Framework perform_create: You cannot call `.save()` after accessing `serializer.data` -

-
i have following viewset: class artistprofileviewset(viewsets.modelviewset): queryset = artistprofile.objects.all() serializer_class = artistprofileserializer def perform_create(self, serializer): if serializer.is_valid(): serializer.save() with following serializers: class simpleartisttrackserializer(serializers.hyperlinkedmodelserializer): class meta: model = artisttrack fields = (...my fields...) class artistprofileserializer(serializers.hyperlinkedmodelserializer): owners = userserializer(many=true, required=false) tracks = simpleartisttrackserializer(many=true, required=false) class meta: model = artistprofile fields = (...my fields...) i getting following error: assertionerror: cannot call `.save()` after accessing `serializer.data`.if need access data before committing database inspect 'serializer.validated_data' instead. i don't see editing serializer.data object. th...
Read more

Why does Go error when trying to marshal this JSON? -

-
i'm trying rather simple example of trying decode json file structs using golang. however, when attempting error that json: cannot unmarshal object go value of type []main.track which don't understand. here's code in question, , json can found here . package main import ( "encoding/json" "fmt" "net/http" "os" ) // tracks group of track types type tracks struct { tracks []track } // track represents singular track type track struct { name string url string artist artist } // artist represents single artist type artist struct { name string mbid string url string } func main() { url := "http://ws.audioscrobbler.com/2.0/?method=geo.gettoptracks&api_key=c1572082105bd40d247836b5c1819623&format=json&country=netherlands" response, err := http.get(url) if err != nil { fmt.printf("%s\n", err) os.exit(1) } de...
Read more