Java tutorial
/* * Copyright 2016 Flipkart Internet Pvt. Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.flipkart.android.proteus.builder; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import android.text.TextUtils; import android.util.Log; import android.view.View; import com.flipkart.android.proteus.DataContext; import com.flipkart.android.proteus.binding.Binding; import com.flipkart.android.proteus.parser.LayoutHandler; import com.flipkart.android.proteus.toolbox.Formatter; import com.flipkart.android.proteus.toolbox.IdGenerator; import com.flipkart.android.proteus.toolbox.ProteusConstants; import com.flipkart.android.proteus.toolbox.Result; import com.flipkart.android.proteus.toolbox.Styles; import com.flipkart.android.proteus.toolbox.Utils; import com.flipkart.android.proteus.view.ProteusView; import com.flipkart.android.proteus.view.manager.ProteusViewManager; import com.flipkart.android.proteus.view.manager.ProteusViewManagerImpl; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonPrimitive; import java.util.HashMap; import java.util.Map; import java.util.regex.Matcher; /** * A layout builder which can parse data bindings before passing it on to {@link SimpleLayoutBuilder} */ public class DataParsingLayoutBuilder extends SimpleLayoutBuilder { private static final String TAG = "LayoutBuilder"; private Map<String, Formatter> formatter = new HashMap<>(); protected DataParsingLayoutBuilder(@NonNull IdGenerator idGenerator) { super(idGenerator); } @Override protected ProteusViewManager createViewManager(LayoutHandler handler, View parent, JsonObject layout, JsonObject data, int index, Styles styles) { ProteusViewManagerImpl viewManager = new ProteusViewManagerImpl(); DataContext dataContext, parentDataContext = null; JsonElement scope = layout.get(ProteusConstants.DATA_CONTEXT); if (parent instanceof ProteusView) { parentDataContext = ((ProteusView) parent).getViewManager().getDataContext(); } if (scope == null || scope.isJsonNull()) { if (parentDataContext != null) { dataContext = new DataContext(parentDataContext); } else { dataContext = new DataContext(); dataContext.setData(data); dataContext.setIndex(index); } } else { if (parentDataContext != null) { dataContext = parentDataContext.createChildDataContext(scope.getAsJsonObject(), index); } else { dataContext = new DataContext(); dataContext.setData(data); dataContext = dataContext.createChildDataContext(scope.getAsJsonObject(), index); } } viewManager.setLayout(layout); viewManager.setDataContext(dataContext); viewManager.setStyles(styles); viewManager.setLayoutBuilder(this); viewManager.setLayoutHandler(handler); return viewManager; } @Override public boolean handleAttribute(LayoutHandler handler, ProteusView view, String attribute, JsonElement value) { if (ProteusConstants.DATA_CONTEXT.equals(attribute)) { return true; } String stringValue = isDataPath(value); if (stringValue != null) { value = this.findAndReplaceValues(handler, view, attribute, stringValue, value); } return super.handleAttribute(handler, view, attribute, value); } private JsonElement findAndReplaceValues(LayoutHandler handler, ProteusView view, String attribute, String stringValue, JsonElement value) { ProteusViewManager viewManager = view.getViewManager(); DataContext dataContext = viewManager.getDataContext(); if (ProteusConstants.isLoggingEnabled()) { Log.d(TAG, "Find '" + stringValue + "' for " + attribute + " for view with " + Utils.getLayoutIdentifier(viewManager.getLayout())); } char firstChar = TextUtils.isEmpty(stringValue) ? 0 : stringValue.charAt(0); String dataPath; Result result; switch (firstChar) { case ProteusConstants.DATA_PREFIX: JsonElement elementFromData; dataPath = stringValue.substring(1); result = Utils.readJson(dataPath, viewManager.getDataContext().getData(), viewManager.getDataContext().getIndex()); if (result.isSuccess()) { elementFromData = result.element; } else { elementFromData = new JsonPrimitive(ProteusConstants.DATA_NULL); } if (elementFromData != null) { value = elementFromData; } addBinding(viewManager, dataPath, attribute, stringValue, false); break; case ProteusConstants.REGEX_PREFIX: Matcher regexMatcher = ProteusConstants.REGEX_PATTERN.matcher(stringValue); String finalValue = stringValue; while (regexMatcher.find()) { String matchedString = regexMatcher.group(0); String bindingName; if (regexMatcher.group(3) != null) { // has NO formatter dataPath = regexMatcher.group(3); result = Utils.readJson(dataPath, viewManager.getDataContext().getData(), viewManager.getDataContext().getIndex()); if (result.isSuccess() && null != result.element) { finalValue = finalValue.replace(matchedString, result.element.getAsString()); } else { finalValue = dataPath; } bindingName = dataPath; } else { // has formatter dataPath = regexMatcher.group(1); String formatterName = regexMatcher.group(2); String formattedValue; result = Utils.readJson(dataPath, viewManager.getDataContext().getData(), viewManager.getDataContext().getIndex()); if (result.isSuccess() && null != result.element) { formattedValue = format(result.element, formatterName); } else { formattedValue = dataPath; } finalValue = finalValue.replace(matchedString, formattedValue != null ? formattedValue : ""); bindingName = dataPath; } addBinding(viewManager, bindingName, attribute, stringValue, true); } // remove the REGEX_PREFIX finalValue = finalValue.substring(1); // return as a JsonPrimitive value = new JsonPrimitive(finalValue); break; } return value; } public String isDataPath(JsonElement element) { if (!element.isJsonPrimitive()) { return null; } String attributeValue = element.getAsString(); if (attributeValue != null && !"".equals(attributeValue) && (attributeValue.charAt(0) == ProteusConstants.DATA_PREFIX || attributeValue.charAt(0) == ProteusConstants.REGEX_PREFIX)) { return attributeValue; } return null; } private void addBinding(ProteusViewManager viewManager, String bindingName, String attributeName, String attributeValue, boolean hasRegEx) { // check if the view is in update mode if not that means that the update flow // is running and we must not add more bindings for they will be duplicates if (!viewManager.isViewUpdating()) { Binding binding = new Binding(bindingName, attributeName, attributeValue, hasRegEx); viewManager.addBinding(binding); } } private String format(JsonElement toFormat, String formatterName) { Formatter formatter = this.formatter.get(formatterName); if (formatter == null) { formatter = Formatter.NOOP; } return formatter.format(toFormat); } @Nullable protected JsonObject onLayoutRequired(String type, ProteusView parent) { if (ProteusConstants.isLoggingEnabled()) { Log.d(TAG, "Fetching child layout: " + type); } if (listener != null) { return listener.onLayoutRequired(type, parent); } return null; } public void registerFormatter(Formatter formatter) { this.formatter.put(formatter.getName(), formatter); } public void unregisterFormatter(String formatterName) { if (Formatter.NOOP.getName().equals(formatterName)) { return; } this.formatter.remove(formatterName); } public Formatter getFormatter(String formatterName) { return this.formatter.get(formatterName); } }