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|InformationRetrieval||Implementers of this interface know how to get data for an information token.|
|InformationToken||Generic class for creating the ability to allow a developer to define a token and how to get the data to replace the values in that token.|
|JspStyleRead||Used to parse an XML file.|
|KnownTemplates||Primarily exists for the sake of storing MergeTemplates.|
|MergeTemplate||How do we handle the generation of code for which there is no corresponding data? For example, A package definition, is not mandatory.|
|TemplatePreprocessor||Read a flatfile and convert it's contexts to a MergeTemplate object, possibly containing some MergeTemplates itself.|
|TokenTableModel||How to display a WorkFlowRule in a table.|
|XMLTemplateRead||This class is used to read the XML file and translate it into KnownTemplates|
|XMLTemplateWriter||Used to dump the templates into an XML file|
Templates provide the ability to create documents by merging application data with a predefined ascii based template. This is usefull for report generation. You can predefine report templates and then generate documents that contain a merge of your application data and the report template. This can be alot better than doing your own printing since you'll delegate that to any program that can read your created document. There are several classes that collaborate to provide this functionality.
The interface com.objectwave.templateMerge.InformationRetrieval is the
simplest participant in this collaboration. Implementors of this interface are the building blocks of the merge
functionallity. For every data element that we will wish to provide as a potential merge data element, will need
to be provided by one of these InformationRetrieval objects. There are two methods to get this information.
The implementor of this interface is probably expecting a certain type object Object to be passed
as the parameter, however, any object could be provided. Normally the implmentor would cast this parameter to be
an object of the appropriate type and then traverse the object strucutre using whatever methods necessary to get
the data the implementor was intended to retrieve.
java.lang.String getStringDataFor(Object obj);
java.util.Enumeration getEnumeration(Object obj);This differs from the previous method in only one way. This method is used when it is expected that
the data we are retrieving will not be limited to a single data element.
For example: A Class has one 'name', so I would use one particular InformationRetrieval object to retreive the name with the getStringDataFor method. A Class has multiple variables. I would create another InformationRetrieval object to retrieve an Enumeration of all of the variable names. The method I would use would be the getEnumeration method. Both of these InformationRetrieval implementation may expect a java.lang.Class object to be the parameter 'obj' to their respective methods.
com.objectwave.templateMerge.InformationToken Is the work horse that will
merge a string with the data returned from the InformationRetrieval object. This object has a TokenString that
it will replace in the original template String with the data returned from the InformationRetrieval object. There
are three types of InformationToken. For these types we will assume that we have been provided a sample Template
with the following string body :
'This is a test %tokenstring%'.
The first is the default type. This type will use the getStringDataFor() method when interacting with the InformationRetrieval. The string returned by this method will then be substituted for all ocurrances of the the TokenString in the the provided template string body. This is basically a simple merge. Imagine that the InformationRetrieval object provided string data 'message'. The output of the template merge would be 'This is a test message'.
Secondly, there is a Iterator type. An iterator type will use the getEnumeration method when interacting with the InformationRetrieval object. It will create a single string that comma separates the elements found in the iteration. It will then replace all occurances of the TokenString found in the template string body with the new comma separated string. If I had two elements in the Enumeration, one & two, the output of the sample template would be : 'This is a test one, two'.
Finally there is the Collection type. A Collection type is similar to the Iterator type in the way it interacts
with InformationRetrieval object. However, for each entry found in the enumeration it will generate a complete
new copy of the original template string body. If I had two elements in the Enumeration, one & two, the output
of the sample template would be : 'This is a test one This is a test two'. Note, since our template contained no
new line operators, the two templates generated one after another.
If there are multiple enumerations in a given template, all enumerations will be advanced for each new merge. If we have two collection tokens with the token strings of %variablename% and %variabletype% and a template string body of '%variabletype% %variablename% \n'. Each token would getEnumeration from their respective InformationRetrieval object. Assuming that the %variablename% token found the two values one & two and the %variabletype% token found the two values int & String, the output would look like this:
com.objectwave.templateMerge.TokenProvider will provide a collection of InformationTokens that can be used in the creation of a MergeTemplate. Since tokens are going be very specific to the application at hand, we have the TokenProvider interface to allow each application to provide thier own set of InformationTokens. This interface is merely a way for the application developer to specify the object in which all of the InformationTokens can be found.
com.objectwave.templateMerge.MergeTemplate Is the class that pulls all of this together. Using some template builder, or just hardcoding them into code, you must create a merge template object. These objects are serializable and can be saved into a data file for later retreival. A merge template contains the string body that is the template to be used by the InformationToken. It also contains a collection InformationToken objects that are expected to be found in the string body.
The merge process is initiated by calling the following method on the MergeTemplate object.
void generateForOn(Object ci, OutputStream stream)This first parameter is the object that will eventually be provided to the InformationRetrieval object.
It is from this object that our StringData or Enumeration of data will be retrieved. When the merge string is created,
the results will be written upon the provided OutputStream.
|-for Each Token--
|-Write result of all
To help provide system users with more freedom in defining the framework of a report to be generated using a
collection of MergeTemplates, the class com.objectwave.templateMerge.TemplatePreprocessor
has been created. This class' principle
methods, given an InputStream and a "master list" of tokens, will return a MergeTemplate object which will be ready to
merge all relevant tokens into the list. The InputStream can contain some special tokens recognized by the TemplatePreprocessor to describe how the MergeTemplate object should be constructed. There are three tags supported:
The actual character strings which represents each of these tags are configurable and also have default values.
In the InputStream, the BeginBlock and EndBlock tags must be properly nested, otherwise an IOException
will be thrown. That is, for every BeginBlock tag, an EndBlock tag must occur later
in the InputStream. All text between a BeginBlock and an EndBlock will become the preBody
text of a new MergeTemplate object, which will become a child of the current MergeTemplate. Thus nested occurances
of blocks will result in a deeper structure of MergeTemplate objects.
Also, for each block the TemplatePreprocessor searches for an identifies what InformationToken tags are associated with
Additionally, every ImportURL tag requires a parameter to follow it to specify the URL of the InputStream to go get. This parameter is either a sequence of non-whitespace characters or any amount of text enclosed by double-quote (") characters. To import another file, say c:\otherStuff.htm, the line of the InputStream may appear as
An example of the contents of a simple file to be "preprocessed" might be the following:
<H2> Fax Machines </H2>
A simpler example describing the same structure is:
this will generate the following structure in the returned MergeTemplate object, supposing that xxx.htm contains
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