Class TagNodeIterator

  • public class TagNodeIterator
    extends java.lang.Object
    TagNode Iterator - Documentation.

    TagNodeIterator =>

    1. TagNode: This implies that only HTML TagaNode's will be used for searching. The field TagNode.tok field is used as a search criteria. This public, final String field contains the name of the HTML Element - for instance, 'div', 'p', 'span', 'img', etc...
      InnerTag's - (a.k.a. 'attributes') - are not part of the search.
    2. Iterator: This means that java Iterator's (extension of java.util.ListIterator<E>) are returned, rather than simple-results or vectors of results. Iterator's make updating a Vector<HTMLNode> much easier (by avoiding the problems caused by stale index-pointers), and usually simply many of the retrieval & removal operations when large HTML TABLE and UL / OL are involved.

    Methods Available

    Method Explanation
    iter (...) Returns a java HNLI<TagNode> that iterates through each node on the html-page Vector which meets the criteria specified.
    exceptIter (...) Returns a java HNLI<TagNode> that iterates through each node on the html-page Vector which does not meet the criteria specified.

    Method Parameters

    Parameter Explanation
    Vector<? extends HTMLNode> html This represents any vectorized HTML page, sub-page, or list of partial-elements.
    TC tagCriteria The three values of enumeration TC are: TC.OpeningTags, TC.ClosingTags and TC.Both. These values specify a search-criteria result set for an HTML TagNode. There are two types of HTML Elements:

    • "opening versions" of the HTML-tag such as: <A HREF="...">
    • "closing versions" of the element such as: </A>.

    NOTE: If parameter 'tagCriteria' is passed a value of TC.Both, then (and this is hopefully obvious), that both 'opening' and 'closing' versions of the tag will be considered to meet / match the search criteria.
    String... htmlTags When this parameter is present, only HTMLNode's which are both instances of class TagNode *and* whose TagNode.tok field String-value matches (is equal to) at least one of the elements in this VarArgs String parameter-set will be considered for a match.

    COMMON EXAMPLES: Some common examples of valid htmlTags are: a, div, img, table, tr, meta as well as all other valid HTML element-tokens.

    NOTE: This comparison is performed using a case-insensitive compare-method

    EXCEPTIONS: If even one of the elements in this parameter-set is an invalid HTML token, an HTMLTokException will be thrown.

    Return Values:

    All methods return an implementation of Iterator: HNLI<TagNode> which returns, one-at-a-time, TagNode's out of the vectorized-HTML page parameter 'html'.

    Static (Functional) API: The methods in this class are all (100%) defined with the Java Key-Word / Key-Concept 'static'. Furthermore, there is no way to obtain an instance of this class, because there are no public (nor private) constructors. Java's Spring-Boot, MVC feature is *not* utilized because it flies directly in the face of the light-weight data-classes philosophy. This has many advantages over the rather ornate Component Annotations (@Component, @Service, @AutoWired, etc... 'Java Beans') syntax:

    • The methods here use the key-word 'static' which means (by implication) that there is no internal-state. Without any 'internal state' there is no need for constructors in the first place! (This is often the complaint by MVC Programmers).
    • A 'Static' (Functional-Programming) API expects to use fewer data-classes, and light-weight data-classes, making it easier to understand and to program.
    • The Vectorized HTML data-model allows more user-control over HTML parse, search, update & scrape. Also, memory management, memory leakage, and the Java Garbage Collector ought to be intelligible through the 'reuse' of the standard JDK class Vector for storing HTML Web-Page data.

    The power that object-oriented programming extends to a user is (mostly) limited to data-representation. Thinking of "Services" as "Objects" (Spring-MVC, 'Java Beans') is somewhat 'over-applying' the Object Oriented Programming Model. Like most classes in the Java-HTML JAR Library, this class backtracks to a more C-Styled Functional Programming Model (no Objects) - by re-using (quite profusely) the key-word static with all of its methods, and by sticking to Java's well-understood class Vector

    Internal-State: A user may click on this class' source code (see link below) to view any and all internally defined fields class. A cursory inspection of the code would prove that this class has precisely zero internally defined global fields (Spaghetti). All variables used by the methods in this class are local fields only, and therefore this class ought to be though of as 'state-less'.

    NOTE: Although this class is 'stateless' (has no internally defined fields at all. Although the Iterator's that are returned do, indeed, have stateful variables.

    View Actual Hi-Lited Code Files: