Unit simpleinternet

DescriptionUsesClasses, Interfaces, Objects and RecordsFunctions and ProceduresTypesConstantsVariables

Description

This unit contains a very simple procedural interface to make http requests and process the returned data.



To get started, you can just use the function retrieve('...url...') to get the data you need as a string.

Retrieve also supports file:// urls or other data source; if you want to restrict it to http GET/POST-requests only, you can use the httpRequest function.

The data can then be processed with process which applies an XPath/XQuery expression or a html template to it.

Example

Get all links on a page:

    for v in process('http://www.freepascal.org', '//a') do
      writeln(v.toString, ' => ', v.toNode['href']);
  

Overview

Functions and Procedures

function retrieve(data: string): string;
function httpRequest(url: string): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';
function httpRequest(url: string; rawpostdata: string): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';
function httpRequest(url: string; postdata: TStringList): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';
function httpRequest(const method, url, rawdata: string): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';
function httpRequest(const destination: xquery.IXQValue): string; overload; deprecated 'Use destination.retrieve() instead.';
function process(data: string; query: string): xquery.IXQValue;
function processedTree: TTreeNode;
function processedVariables: TXQVariableChangeLog;
procedure freeThreadVars;
function defaultInternet: TInternetAccess; inline;
function defaultQueryEngine: TXQueryEngine; inline;
procedure needInternetAccess; deprecated 'This procedure no longer does anything';

Types

IXQValue = xquery.IXQValue;

Description

Functions and Procedures

function retrieve(data: string): string;

Retrieve data from any url.

It is really simple to use, you pass the desired url as single parameter and get the data of the url.

It supports:

function httpRequest(url: string): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';

Warning: this symbol is deprecated: The httpRequest functions have been moved to the internetaccess unit.

 
function httpRequest(url: string; rawpostdata: string): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';

Warning: this symbol is deprecated: The httpRequest functions have been moved to the internetaccess unit.

 
function httpRequest(url: string; postdata: TStringList): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';

Warning: this symbol is deprecated: The httpRequest functions have been moved to the internetaccess unit.

 
function httpRequest(const method, url, rawdata: string): string; overload; deprecated 'The httpRequest functions have been moved to the internetaccess unit.';

Warning: this symbol is deprecated: The httpRequest functions have been moved to the internetaccess unit.

 
function httpRequest(const destination: xquery.IXQValue): string; overload; deprecated 'Use destination.retrieve() instead.';

Warning: this symbol is deprecated: Use destination.retrieve() instead.

Make a http request to an address given in an IXQValue.
node: if a link (a), download @href. If a resource (img, frame), download @src. Otherwise download the text
. object: Download obj.url, possibly sending obj.post as postdata. else: Download the string value.

function process(data: string; query: string): xquery.IXQValue;

Processes data with a certain query.

data can be an url, or a html/xml file in a string, like in retrieve.

query can be a XPath/XQuery expression, like in process('http://www.google.de', '//title');.

Or query can be a html template like process('http://www.google.de', '<title><t:s>result:=text()</t:s></title>'); The advantage of such templates is that they can return several variables at once and a canonical representation of the same data on different web sites. To get a list of all variables of the last query you can use processedVariables.

This function returns an IXQValue value, which is a variant for XQuery expression. If you want a string value, you can convert it like process(...).toString. Or if you want to access a retrieved node directly, you can use process(..).toNode.
It can also contain multiple values, which can be access like for x in process(..), where x is another IXQValue.

The global function processedTree returns a tree representation of the last processed data string.

function processedTree: TTreeNode;

Returns a tree representation of the last processed html/xml data
Might return nil

function processedVariables: TXQVariableChangeLog;

Returns all variable assignments during the last query

procedure freeThreadVars;

If you use the functions in this unit from different threads, you have to call freeThreadVars before the thread terminates to prevent memory leaks
This also calls freeThreadVars of the xquery and internetaccess units

function defaultInternet: TInternetAccess; inline;
 
function defaultQueryEngine: TXQueryEngine; inline;
 
procedure needInternetAccess; deprecated 'This procedure no longer does anything';

Warning: this symbol is deprecated: This procedure no longer does anything

 

Types

IXQValue = xquery.IXQValue;

IXQValue from the xquery unit. Just a wrapper, so that no other unit needs to be included


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