How to do a findViewById (R.id.>> StringVarHere << )?

Question

Searched and working on this a long while - no luck. ( It must be simple ? Thanks for the assist. )

Trying to get / set a screen full of EditTexts' text, but not with the usual, more hard-coded way:

... findViewById (R.id.SomeTextWidgetId) ;

Instead, I'm trying to figure out a reusable way via a variable holding the (String) name_of_widget.

In psuedo code:

findViewById (R.id.>> StringVarHere << ); // how to do that ?

I tried also this findViewById method, but it didn't work (!?)

//// given:

static final String FIELD_TV_FEE   = "TextViewFee" ;
static final String FIELD_TV_FOO   = "TextViewFoo" ;
static final String FIELD_TV_FUM   = "TextViewFum" ;
//// and some arbitrary number more of similar fields  

static final String [] ALL_FIELDS = {

    FIELD_TV_FEE ,
    FIELD_TV_FOO ,  
    FIELD_TV_FUM   // ...
 } ; 

//// ...

    //// this part works
    int ResourceID;
    String stringVarHere = FIELD_TV_FEE; 

    //// outputs a correct id, say '0x7f05000f' as in R.id.xxx below
    ResourceID = context
                       .getResources()
                       .getIdentifier ( stringVarHere,
                                        "id", 
                                        context 
                                          .getApplicationInfo()
                                          .packageName
                                      ) ;
    Log.d ("MyClass" , "RESID = " + Integer.toHexString(ResourceID) ) ;  
/*
 * that's where I'm stuck ^^^ ... how do I do:
 */

String field_name ;

for ( field_name : ALL_FIELDS ) {
    (EditText) SomethingLike_a_findViewById(field_name).setText ("Hello Wurld") ;
}

I've tried .setId ...

//// details

    <!-- excerpt from working xml layout -->
    <EditText
        android:id="@+id/TextViewFee"
        android:inputType="text"
        android:layout ... etc ...         
        />
    <EditText
        android:id="@+id/TextViewFoo"
        android:inputType="text"
        android:layout ... etc ...         
        />
    <EditText
        android:id="@+id/TextViewFum"
        android:inputType="text"
        android:layout ... etc ...         
        />

As expected, the gen'ed R file has something like this:

// ...
public static final class id {
    public static final int TextViewFee=0x7f05000f;
    public static final int TextViewFum=0x7f05001c;
    public static final int TextViewFoo=0x7f05001d;
    // ... etc

---

Yes, thanks - it makes sense to do it in the activity. I was trying to keep it from getting too code bulky. Here's what I'm doing now, based on your and A-C's helpful suggestions. The intention is to get all the text of fields of a form back in one String[]. (I know I could brute force all the fields too.)

What do you all think about this below - seems very similar to your suggestion, madlymad ? I am wondering if this is a poor design approach ?

public class FoodBar {

private Activity activity; 
private Context ctx;

public  FoodBar ( Activity _activity ) {        
    this.activity = _activity;
    this.ctx = this.activity.getApplicationContext() ;
}

public String[] getTextFromAllEditTexts () { // the UI views

    int res_id = 0;
    int i = 0;   

    String [] retValues = new String [MyClassName.ALL_FIELDS_LENGTH] ;

    for (String field : MyClassName.ALL_FIELDS_ALL_VEHICLES) {

       res_id = this.ctx.getResources()
                        .getIdentifier ( field, "id", this.ctx.getPackageName() );

           ((EditText) this.activity
                           .findViewById (res_id))
                           .setText( "Meat and Potatoes" ) ;

               // redundant - get it right back to make sure it really went in !  
        retVal[i++] = ((EditText) this.activity
                                        .findViewById (res_id))
                                        .getText().toString() ;
    }

     return retVal;

} // end func
} // end class

Then from the Activity class, it's just:

String [] theFields = null;
FoodBar = new FoodBar (this);

try {

     theFields = FoodBar.getTextFromAllEditTexts ();

} catch (Exception e) {
     Log.d ("OOPS", "There's a big mess in the Foodbar: " + e.toString() );
}

Answer 1

The way you could do it is (as I understand the way you are trying):

This can be in non-Activity (YourClassname.java):

public static int getMyId(Context context, String field) {
     return context.getResources().getIdentifier (field, "id", context.getPackageName());
}

in Activity-class:

for ( String field_name : YourClassname.ALL_FIELDS ) {
    int resid = YourClassname.getMyId(context, field_name);
    if(resid != 0) { // 0 = not found 
       EditText et = (EditText) findViewById(resid);
       if (et != null) {
          et .setText ("Hello Wurld") ;
       }
    }
}

---

But I think it's better to code in the activity class like:

String packageName = getPackageName();
Resources res = getResources();
for ( String field_name : YourClassname.ALL_FIELDS ) {
    int resid = res.getIdentifier (field_name, "id", packageName);
    if(resid != 0) {// 0 = not found 
       EditText et = (EditText) findViewById(resid);
       if (et != null) {
          et .setText ("Hello Wurld") ;
       }
    }
}

Answer 2

A-C suggested something along the lines of:

res_id = getResources().getIdentifier (field, "id", getPackageName());
((EditText)findViewById (res_id)).setText("NoLongerFubar");

this DOES work - when I tried it standalone in a test rig. Thanks ! Still not sure what was blowing up, but I suspect it was Context or Resource items not being accessible.