I was trying to make an advanced TinyDB extension in Niotron IDE from App Inventor Sources, and when compiling the extension in Niotron IDE, I encountered two errors. I didn’t understand why the errors appeared.
Started Compiling Project TinyDBE
Buildfile: /compiler/android/build.xml
javac:
[mkdir] Created dir: /compiler/android/build/roFHy/classes
[javac] Compiling 1 source file to /compiler/android/build/roFHy/classes
[javac] warning: [options] bootstrap class path not set in conjunction with -source 1.7
[javac] Note: Wrote file file:/compiler/android/build/roFHy/classes/simple_components.json
[javac] Note: Wrote file file:/compiler/android/build/roFHy/classes/simple_components.txt
[javac] Note: Wrote file file:/compiler/android/build/roFHy/classes/simple_components_build_info.json
[javac] Note: Wrote file file:/compiler/android/build/roFHy/classes/AutogeneratedOdeMessages.java
[javac] Note: Wrote file file:/compiler/android/build/roFHy/classes/ComponentsTranslation.java
[javac] /compiler/android/src/roFHy/com/gordonlu/tinydbe/TinyDBE.java:40: error: cannot find symbol
[javac] public class TinyDBE extends AndroidNonvisibleComponent implements Component, Deletable{
[javac] ^
[javac] symbol: class Component
[javac] /compiler/android/src/roFHy/com/gordonlu/tinydbe/TinyDBE.java:40: error: cannot find symbol
[javac] public class TinyDBE extends AndroidNonvisibleComponent implements Component, Deletable{
[javac] ^
[javac] symbol: class Deletable
[javac] 2 errors
This was the source code of the extension.
package com.gordonlu.tinydbe;
import android.app.Activity;
import android.content.Context;
import com.google.appinventor.components.annotations.*;
import com.google.appinventor.components.common.ComponentCategory;
import com.google.appinventor.components.runtime.AndroidNonvisibleComponent;
import com.google.appinventor.components.runtime.ComponentContainer;
import com.google.appinventor.components.runtime.EventDispatcher;
import com.google.appinventor.components.common.YaVersion;
import com.google.appinventor.components.runtime.errors.YailRuntimeError;
import com.google.appinventor.components.runtime.util.JsonUtil;
import com.google.appinventor.components.common.PropertyTypeConstants;
import com.google.appinventor.components.annotations.SimpleFunction;
import com.google.appinventor.components.annotations.DesignerComponent;
import com.google.appinventor.components.annotations.DesignerProperty;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import android.content.Context;
import android.content.SharedPreferences;
import org.json.JSONException;
@DesignerComponent(
version = 1,
description = "TinyDBE is an enhanced version of TinyDB, with additional blocks.",
category = ComponentCategory.EXTENSION,
nonVisible = true,
iconName = "https://docs.google.com/drawings/d/e/2PACX-1vQCI87PHLBF0jb8QWyYmIRQSjjNW3EFXf-qpsWCvBYkUQ9vEgPAB8SpxcMpblxNpbIYrjCjLrRLIU2c/pub?w=16&h=16")
//Libraries
@UsesLibraries(libraries = "")
//Permissions
@UsesPermissions(permissionNames = "")
public class TinyDBE extends AndroidNonvisibleComponent implements Component, Deletable{
public TinyDBE(ComponentContainer container){
super(container.$form());
this.activity = container.$context();
this.context = container.$context();
Namespace(DEFAULT_NAMESPACE);
}
public static final String DEFAULT_NAMESPACE="TinyDB1";
private SharedPreferences sharedPreferences;
private String namespace;
private Context context;
private Activity activity;
@SimpleProperty(description = "Namespace for storing data.", category = PropertyCategory.BEHAVIOR)
@DesignerProperty(editorType = PropertyTypeConstants.PROPERTY_TYPE_STRING, defaultValue = DEFAULT_NAMESPACE)
public void Namespace(String namespace) {
this.namespace = namespace;
sharedPreferences = context.getSharedPreferences(namespace, Context.MODE_PRIVATE);
}
@SimpleProperty(description = "Namespace for storing data.")
public String Namespace() {
return namespace;
}
/**
* Store the given `valueToStore`{:.variable.block} under the given `tag`{:.text.block}.
* The storage persists on the phone when the app is restarted.
*
* @param tag The tag to use
* @param valueToStore The value to store. Can be any type of value (e.g.
* number, text, boolean or list).
*/
@SimpleFunction(description = "Store the given value under the given tag. The storage persists "
+ "on the phone when the app is restarted.")
public void StoreValue(final String tag, final Object valueToStore) {
final SharedPreferences.Editor sharedPrefsEditor = sharedPreferences.edit();
try {
sharedPrefsEditor.putString(tag, JsonUtil.getJsonRepresentation(valueToStore));
sharedPrefsEditor.commit();
} catch (JSONException e) {
throw new YailRuntimeError("Value failed to convert to JSON.", "JSON Creation Error.");
}
}
/**
* Retrieve the value stored under the given `tag`{:.text.block}. If there's no such tag, then
* return `valueIfTagNotThere`{:.variable.block}.
*
* @param tag The tag to use
* @param valueIfTagNotThere The value returned if tag in not in TinyDB
* @return The value stored under the tag. Can be any type of value (e.g.
* number, text, boolean or list).
*/
@SimpleFunction(description = "Retrieve the value stored under the given tag. If there's no "
+ "such tag, then return valueIfTagNotThere.")
public Object GetValue(final String tag, final Object valueIfTagNotThere) {
try {
String value = sharedPreferences.getString(tag, "");
// If there's no entry with tag as a key then return the empty string.
// was return (value.length() == 0) ? "" : JsonUtil.getObjectFromJson(value);
return (value.length() == 0) ? valueIfTagNotThere : JsonUtil.getObjectFromJson(value, true);
} catch (JSONException e) {
throw new YailRuntimeError("Value failed to convert from JSON.", "JSON Creation Error.");
}
}
/**
* Return a list of all the tags in the data store.
*
* @return a list of all keys.
*/
@SimpleFunction(description = "Return a list of all the tags in the data store.")
public Object GetTags() {
List<String> keyList = new ArrayList<String>();
Map<String,?> keyValues = sharedPreferences.getAll();
// here is the simple way to get keys
keyList.addAll(keyValues.keySet());
java.util.Collections.sort(keyList);
return keyList;
}
@SimpleFunction(description = "Clears the tags that matches the names in the list.")
public void ClearTags(final String tags) {
List<String> keyList = new ArrayList<String>();
Map<String,?> keyValues = sharedPreferences.getAll();
// here is the simple way to get keys
keyList.addAll(keyValues.keySet());
java.util.Collections.sort(keyList);
String list = keylist;
if (!tags.isEmpty()) {
for (E element : tags) {
if (list.contains(element)) {
final SharedPreferences.Editor sharedPrefsEditor = sharedPreferences.edit();
sharedPrefsEditor.remove(element);
sharedPrefsEditor.commit();
}
}
}
}
/**
* Clear the entire data store.
*
*/
@SimpleFunction(description = "Clear the entire data store.")
public void ClearAll() {
final SharedPreferences.Editor sharedPrefsEditor = sharedPreferences.edit();
sharedPrefsEditor.clear();
sharedPrefsEditor.commit();
}
/**
* Clear the entry with the given `tag`{:.text.block}.
*
* @param tag The tag to remove.
*/
@SimpleFunction(description = "Clear the entry with the given tag.")
public void ClearTag(final String tag) {
final SharedPreferences.Editor sharedPrefsEditor = sharedPreferences.edit();
sharedPrefsEditor.remove(tag);
sharedPrefsEditor.commit();
}
@Override
public void onDelete() {
final SharedPreferences.Editor sharedPrefsEditor = sharedPreferences.edit();
sharedPrefsEditor.clear();
sharedPrefsEditor.commit();
}
}
From the error, it has something to do with implements Component, Deletable, I just want to know how I can fix it.
Can somebody help me?
. I don’t understand.