{
* This Source Code Form is subject to the terms of the Mozilla Public License,
* v. 2.0. If a copy of the MPL was not distributed with this file, You can
* obtain one at http://mozilla.org/MPL/2.0/
*
* Copyright (C) 2008-2012, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Implements a class that helps with parsing of a snippet's extra property as
* active text and vice versa.
}
unit USnippetExtraHelper;
interface
uses
// Project
ActiveText.UMain, UBaseObjects, UIStringList;
type
{
TSnippetExtraHelper:
Class that helps with the parsing of a snippet's Extra property as active
text and vice versa.
}
TSnippetExtraHelper = class(TNoConstructObject)
public
class function BuildActiveText(const PrefixText, CreditsMarkup,
URL: string): IActiveText; overload;
{Builds an active text object containing some plain followed by active
text defined by markup in the "Credits" format.
@param PrefixText [in] PrefixText text. If not empty string this is
added as plain text before any credits markup.
@param CreditsMarkup [in] "Credits" markup. May contain a link indicated
by bracketed text. Both plain text and links can be generated. May be
empty string.
@param URL [in] URL to use in any link defined in CreditsMarkup.
@return Required active text object. Will be an empty object if both
PrefixText and CreditsMarkup are empty.
}
class function BuildActiveText(const REML: string): IActiveText; overload;
{Builds an active text object from a string containing markup in REML
format.
@param REML [in] REML markup language that defines active text.
@return Required active text object. Will be an empty object if REML is
empty string.
}
class function BuildREMLMarkup(const ActiveText: IActiveText): string;
{Creates REML markup from an active text object using latest version.
@param ActiveText [in] Active text object used to generate markup.
@return Required REML markup.
}
/// <summary>Converts given plain text into an active text paragraph.
/// </summary>
/// <remarks>All text is treated as one paragraph, embedded newlines are
/// ignored. Text is trimmed of leading and trailing spaces. If trimmed
/// text is empty, empty active text is returned.</remarks>
class function PlainTextToActiveText(Text: string): IActiveText;
end;
implementation
uses
// Delphi
SysUtils,
// Project
UREMLDataIO, USnippetCreditsParser, UStrUtils;
{ TSnippetExtraHelper }
class function TSnippetExtraHelper.BuildActiveText(const PrefixText,
CreditsMarkup, URL: string): IActiveText;
{Builds an active text object containing some plain followed by active text
defined by markup in the "Credits" format.
@param PrefixText [in] PrefixText text. If not empty string this is added as
plain text before any credits markup.
@param CreditsMarkup [in] "Credits" markup. May contain a link indicated by
bracketed text. Both plain text and links can be generated. May be empty
string.
@param URL [in] URL to use in any link defined in CreditsMarkup.
@return Required active text object. Will be an empty object if both
PrefixText and CreditsMarkup are empty.
}
begin
// Create new empty active text object
Result := TActiveTextFactory.CreateActiveText;
if (PrefixText <> '') then
begin
// We have prefix text: add it to result as a paragraph containing a single
// text element
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsOpen));
Result.AddElem(
TActiveTextFactory.CreateTextElem(StrMakeSentence(PrefixText))
);
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsClose));
end;
if (CreditsMarkup <> '') then
begin
// We have credits: add credits and any hyperlink as a paragraph
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsOpen));
Result.Append(
TActiveTextFactory.CreateActiveText(
StrMakeSentence(CreditsMarkup),
TSnippetCreditsParser.Create(URL)
)
);
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsClose));
end;
end;
class function TSnippetExtraHelper.BuildActiveText(
const REML: string): IActiveText;
{Builds an active text object from a string containing markup in REML format.
@param REML [in] REML markup language that defines active text.
@return Required active text object. Will be an empty object if REML is
empty string.
}
function IsBlockOpener(Elem: IActiveTextElem): Boolean;
var
ActionElem: IActiveTextActionElem;
begin
if not Supports(Elem, IActiveTextActionElem, ActionElem) then
Exit(False);
Result := (ActionElem.DisplayStyle = dsBlock)
and (ActionElem.State = fsOpen);
end;
function IsBlockCloser(Elem: IActiveTextElem): Boolean;
var
ActionElem: IActiveTextActionElem;
begin
if not Supports(Elem, IActiveTextActionElem, ActionElem) then
Exit(False);
Result := (ActionElem.DisplayStyle = dsBlock)
and (ActionElem.State = fsClose);
end;
type
/// <summary>Describes different parts of parsed REML code in relation to
/// block tags.</summary>
/// <remarks>Can be within a pair of block tags; without, i.e. not enclosed
/// by block tags or in the transitional state between one and the other.
/// </remarks>
TBlockState = (bsWithin, bsWithout, bsTransition);
var
ActiveText: IActiveText; // receives active text built from REML
TextElem: IActiveTextTextElem;
Text: string;
BlockState: TBlockState; // state of current position relating to block tags
Elem: IActiveTextElem; // each element in active text
begin
Result := TActiveTextFactory.CreateActiveText;
if REML = '' then
Exit;
// Create active text by parsing REML
ActiveText := TActiveTextFactory.CreateActiveText(REML, TREMLReader.Create);
if ActiveText.IsEmpty then
Exit;
// Scan active text, inserting paragraph level block tags where the active
// text is not enclosed by them: this can be at the start, at the end or
// between existing blocks. E.g for "xxx <p>yyy</p> xxx <p>yyy</p> xxx", xxx
// is without any block and will be enclosed in paragraphs while yyy is within
// a block and will be unchanged.
BlockState := bsTransition;
for Elem in ActiveText do
begin
if IsBlockOpener(Elem) then
begin
Assert(BlockState <> bsWithin,
ClassName + '.BuildActiveText: Block is nested.');
if BlockState = bsWithout then
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsClose));
Result.AddElem(Elem);
BlockState := bsWithin;
end
else if IsBlockCloser(Elem) then
begin
Assert(BlockState = bsWithin,
ClassName + '.BuildActiveText: Block closer outside block.');
Result.AddElem(Elem);
BlockState := bsTransition;
end
else
begin
if BlockState = bsTransition then
begin
if Supports(Elem, IActiveTextTextElem, TextElem) then
begin
// make sure we don't start a paragraph block if text contains only
// spaces
Text := StrTrimLeft(TextElem.Text);
if Text <> '' then
begin
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsOpen));
Result.AddElem(TActiveTextFactory.CreateTextElem(Text));
BlockState := bsWithout;
end;
end
else
begin
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsOpen));
Result.AddElem(Elem);
BlockState := bsWithout;
end;
end
else
Result.AddElem(Elem);
end;
end;
if BlockState = bsWithout then
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsClose));
end;
class function TSnippetExtraHelper.BuildREMLMarkup(
const ActiveText: IActiveText): string;
{Creates REML markup from an active text object using latest version.
@param ActiveText [in] Active text object used to generate markup.
@return Required REML markup.
}
begin
Result := TREMLWriter.Render(ActiveText);
end;
class function TSnippetExtraHelper.PlainTextToActiveText(
Text: string): IActiveText;
begin
Result := TActiveTextFactory.CreateActiveText;
Text := StrTrim(Text);
if Text = '' then
Exit;
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsOpen));
Result.AddElem(
TActiveTextFactory.CreateTextElem(Text)
);
Result.AddElem(TActiveTextFactory.CreateActionElem(ekPara, fsClose));
end;
end.
