com.adobe.granite.ui.components.htl.ComponentHelper Maven / Gradle / Ivy
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* Copyright 2016 Adobe Systems Incorporated
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* NOTICE: All information contained herein is, and remains
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* if any. The intellectual and technical concepts contained
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package com.adobe.granite.ui.components.htl;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import javax.script.Bindings;
import javax.servlet.ServletException;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.scripting.SlingBindings;
import org.apache.sling.api.scripting.SlingScriptHelper;
import org.apache.sling.api.wrappers.SlingHttpServletResponseWrapper;
import org.apache.sling.scripting.sightly.pojo.Use;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.adobe.granite.ui.components.AttrBuilder;
import com.adobe.granite.ui.components.Options;
import com.adobe.granite.ui.components.impl.BaseComponentHelper;
import com.adobe.granite.xss.XSSAPI;
import com.day.cq.i18n.I18n;
/**
* A convenient base Use class for development of Granite UI components that are
* implemented using HTL.
*/
public abstract class ComponentHelper implements Use {
private static final Logger LOG = LoggerFactory.getLogger(ComponentHelper.class);
private BaseComponentHelper base;
private StringWriter writer;
private SlingBindings slingBindings = new SlingBindings();
private Resource resource;
private ResourceResolver resourceResolver;
private AttrBuilder attrs;
/**
* Initialize bindings and calls #activate()
*
* @param scriptBindings
* Bindings to be used, there is no guarantee of having any
* particular bindings available.
*/
@Override
public final void init(Bindings scriptBindings) {
slingBindings.putAll(scriptBindings);
writer = new StringWriter();
SlingScriptHelper sling = slingBindings.getSling();
if (sling == null) {
throw new RuntimeException("SlingScriptHelper is not available");
}
SlingHttpServletRequest request = slingBindings.getRequest();
if (request == null) {
throw new RuntimeException("SlingHttpServletRequest is not available");
}
base = new BaseComponentHelper(sling, request,
new PrintWriterResponseWrapper(new PrintWriter(writer), slingBindings.getResponse()));
try {
activate();
} catch (Exception e) {
LOG.error("Failed to activate Use class", e);
}
}
/**
* Dependency Injection setter for inject the SlingBindings A subclass has the
* possibility to override the used SlingBindings
*
* @param slingBindings
* SlingBindings to be used.
*/
protected final void setSlingBindings(@Nonnull SlingBindings slingBindings) {
this.slingBindings = slingBindings;
}
/**
* Dependency Injection setter for inject the BaseComponentHelper A subclass has
* the possibility to override the used BaseComponentHelper
*
* @param baseHelper
* BaseComponentHelper to be used.
*/
protected final void setBaseComponentHelper(@Nonnull BaseComponentHelper baseHelper) {
this.base = baseHelper;
}
private class PrintWriterResponseWrapper extends SlingHttpServletResponseWrapper {
private final PrintWriter writer;
/**
* Create a wrapper for the supplied wrappedRequest
*
* @param writer
* - the base writer
* @param wrappedResponse
* - the wrapped response
*/
public PrintWriterResponseWrapper(@Nonnull PrintWriter writer, SlingHttpServletResponse wrappedResponse) {
super(wrappedResponse);
this.writer = writer;
}
@Override
public PrintWriter getWriter() throws IOException {
return writer;
}
}
/**
* Implement this method to perform post initialization tasks. This is called
* from the {@link ComponentHelper#init(Bindings)}.
*
* @throws Exception
* in case of any error during activation
*/
protected abstract void activate() throws Exception;
/**
* Get an object associated with the given name.
*
* @param name
* Object property name
* @param type
* Expected object type
* @param
* The type of the object
*
* @return Object or {@code null} if Object cannot be found or typed.
*/
@CheckForNull
protected final T get(String name, Class type) {
Object obj = slingBindings.get(name);
try {
return type.cast(obj);
} catch (ClassCastException e) {
LOG.error("Failed to cast value", e);
}
return null;
}
/**
* Gets the current {@link SlingHttpServletRequest}.
*
* @return The current {@link SlingHttpServletRequest}
*/
@Nonnull
protected final SlingHttpServletRequest getRequest() {
return base.getRequest();
}
/**
* Gets the current {@link Resource}
*
* @return The current {@link Resource}
*/
@SuppressWarnings("null")
@Nonnull
protected final Resource getResource() {
if (resource == null) {
resource = slingBindings.getResource();
}
return resource;
}
/**
* Gets the current request's {@link ResourceResolver}.
*
* @return The current request's {@link ResourceResolver}
*/
@SuppressWarnings("null")
@Nonnull
protected final ResourceResolver getResourceResolver() {
if (resourceResolver == null) {
resourceResolver = getRequest().getResourceResolver();
}
return resourceResolver;
}
/**
* Gets the options passed by the calling component.
*
* @return The {@link Options} passed by the calling component
*/
@Nonnull
protected final Options getOptions() {
return base.getOptions();
}
/**
* Gets an {@link I18n} helper for the current request.
*
* @return The {@link I18n} helper for the current request
*/
@Nonnull
protected final I18n getI18n() {
return base.getI18n();
}
/**
* Gets a {@link XSSAPI} helper.
*
* @return The {@link XSSAPI} helper
*/
@Nonnull
protected final XSSAPI getXss() {
return base.getXss();
}
/**
* Gets the attributes passed by the calling component
*
* @return The {@link AttrBuilder} with inherited attributes
*/
@SuppressWarnings("null")
@Nonnull
protected final AttrBuilder getInheritedAttrs() {
if (attrs == null) {
attrs = base.consumeTag().getAttrs();
}
if (attrs == null) {
attrs = new AttrBuilder(getRequest(), base.getXss());
}
return attrs;
}
/**
* Includes the given resource with the given resourceType and passes the given
* options to its renderer. This method performs similarly to <sling:include
* resource="" replaceSelectors="" resourceType="" />.
*
* @param resource
* the resource to include
* @param resourceType
* the resource type
* @param selectors
* the selectors to be included as part of the request.
* @param options
* the options
* @return Output from included resource
* @throws ServletException
* in case there's a servlet error
* @throws IOException
* in case there's an i/o error
*/
@SuppressWarnings("null")
@Nonnull
protected String include(@Nonnull Resource resource, @CheckForNull String resourceType,
@CheckForNull String selectors, @Nonnull Options options) throws ServletException, IOException {
base.include(resource, resourceType, selectors, options);
return writer.toString();
}
/**
* Calls the given script and passes the given options to its renderer. This
* method performs similarly to <sling:call script="" />.
*
* @param script
* the script to be called
* @param options
* the options
* @return Output from included script
* @throws ServletException
* in case there's a servlet error
* @throws IOException
* in case there's an i/o error
*/
@SuppressWarnings("null")
@Nonnull
protected String call(@Nonnull String script, @Nonnull Options options) throws ServletException, IOException {
base.call(script, options);
return writer.toString();
}
/**
* Populates the common attributes to the given {@link AttrBuilder}.
*
* @param attrs
* the attribute builder
*/
protected void populateCommonAttrs(@Nonnull AttrBuilder attrs) {
base.populateCommonAttrs(attrs);
}
}