External redirect for an AEM page

In order to redirect an AEM page to external url follow the below steps

• Create a page with sling:resourceType=foundation/components/redirect. 
• Goto page properties, assign the redirect url
• Open the page in either publisher or in author instance append ?wcmmode=disabled. Now page redirect to external url.

Using the Java Query Object Model within Adobe Experience Manager

You can create an AEM application that searches the CQ repository for JCR data and displays results to the end user. For example, you can search CQ pages under a specific repository node (for example, nodes under /content) and look for a specific search term. All content that satisfy the search criteria are included in the search results. To search the Experience Manager repository, you use the JCR Query Object Model (JQOM) API. For information about the API, see Interface QueryObjectModel. 

JQOM is an AEM query language that is like ‘prepared statements’ and SQL2 is like ‘statements’ in JDBC queries. For example, a use case may require all JCR nodes from ‘Geometrixx’ which has the property pageTitle.

Selector selector = qf.selector("cq:PageContent", "s"); 
Constraint constriant = qf.descendantNode("s", "/content/geometrixx");
constriant = qf.and(constriant, qf.propertyExistence("s", "pageTitle"));
QueryObjectModel qm = qf.createQuery(selector, constriant, null, null);

QueryObjectModelFactory gets the instance of the JCR Object Model.  The Selector is used to set the type of node that the query needs to look at. The s parameter is simply an alias. Constraint is used to add all the constraints which is like a where condition into the query model. Finally a query is created with the selector and constraint that captures the response as a QueryObjectModel. 

JQOM Results

Read More

Uncaught TypeError: Cannot read property 'extend' of undefined' - cq.extend

When we try to create a custom widget we extend the widget from the CompositeField. When we render this custom widget script, we may get error like "Uncaught TypeError: Cannot read property 'extend' of undefined' ".

Solution:

When custom component adds a dependency on cq.widgets it will always fail in the publisher.

When we include below statement in clientlibs, this script is also evaluated in the publisher for the purpose of assigning the variable, even if it is never used.

Search.CustomWidget = CQ.Ext.extend(CQ.form.CompositeField, { 

You can make this work by having the authoring part completely separated from the rest of the component, so that the publisher never tries to execute any part of it. For example by using a different category which is only included using WCMMode.fromRequest(request) != WCMMode.DISABLED

Adobe AEM - Cross Domain AJAX Request

A common problem for developers is a browser to refuse access to a remote resource. Usually, this happens when you execute AJAX cross domain request using jQuery or plain XMLHttpRequest. As result is that the AJAX request is not performed and data are not retrieved.

Figure 1. The same-origin policy restriction in effect

ERROR:

XMLHttpRequest cannot load http://remote-domain/url. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://localhost:5433' is therefore not allowed access

SAME-ORIGIN POLICY

This is a security policy who defines the rules of how a web page can access an external resource (e.g. fonts, AJAX requests). Under the same-origin policy, web browsers do not permit a web page to access resources who origin differ than that of the current page. The origin is considered to be different when the scheme, hostname or port of the resource do not match that of the page. Overcoming the limitations of same-origin security policy is possible using a technique called Cross-origin resource sharing or simply CORS.

Hooking to Cache Invalidation in AEM 6.1

If you need to implement custom cache invalidation based on some event, you can write a workflow service or servlet (Which ever suits best to your requirement). In this Java class you can write code to handle this. The OOTB Flush Service can be utilized for this purpose-

    import com.adobe.cq.social.ugcbase.dispatcher.api.FlushService;

    @Reference

    FlushService flushService;

Then you can simply request a cache invalidation for the corresponding page-

flushService.sendFlushUrl("userId",

                    FlushService.FlushType.IMMEDIATE_FLUSH, resourceUrl,

                    FlushService.RefetchType.IMMEDIATE_REFETCH,

                    new String[] { resourceUrl });

Here resourceUrl is the path of the page without html extension.

In order to make the flush service working properly, create flush agents for each dispathcer with following additional settings-

1. Set the Request method - "POST" because this service expects a POST method flush agent.

2. Send additional parameter for "resource only replication" 

-To debug any issues you can add a custom logger from OSGi configurations console on this package-

com.adobe.cq.social.ugcbase.dispatcher.impl.FlushServiceImpl

ACM AEM Commons tool also provides options to help implementing cache invalidation for you through OSGi configurations.

Read More

Image upload issue in Internet Explorer from Author Dispatcher

If you came to happen to  face issue with image upload from AEM author through dispatcher, this article may help you. You may face issue when you upload an image from image component or uploading images through Assets dashboard. Performing the following things may fix this issue for you-

1. Increase the Upload Buffer Size from OSGi Console (http://host:port/system/console/configMgr)
   Configure service - "Apache Felix Jetty Based Http Service"
Increase following two parameters- "Request Buffer Size" and "Response Buffer Size" to 65536  or a reasonable limit as per your application requirement.