Cutelee  6.1.0
ifchanged.cpp
1 /*
2  This file is part of the Cutelee template system.
3 
4  Copyright (c) 2009,2010 Stephen Kelly <steveire@gmail.com>
5 
6  This library is free software; you can redistribute it and/or
7  modify it under the terms of the GNU Lesser General Public
8  License as published by the Free Software Foundation; either version
9  2.1 of the Licence, or (at your option) any later version.
10 
11  This library is distributed in the hope that it will be useful,
12  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  Lesser General Public License for more details.
15 
16  You should have received a copy of the GNU Lesser General Public
17  License along with this library. If not, see <http://www.gnu.org/licenses/>.
18 
19 */
20 
21 #include "ifchanged.h"
22 
23 #include "parser.h"
24 
25 #include <QtCore/QDateTime>
26 
27 IfChangedNodeFactory::IfChangedNodeFactory() {}
28 
29 Node *IfChangedNodeFactory::getNode(const QString &tagContent, Parser *p) const
30 {
31 #if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
32  auto expr = tagContent.split(QLatin1Char(' '), QString::SkipEmptyParts);
33 #else
34  auto expr = tagContent.split(QLatin1Char(' '), Qt::SkipEmptyParts);
35 #endif
36 
37  expr.takeAt(0);
38  auto n = new IfChangedNode(getFilterExpressionList(expr, p), p);
39 
40  auto trueList
41  = p->parse(n, {QStringLiteral("else"), QStringLiteral("endifchanged")});
42  n->setTrueList(trueList);
43  NodeList falseList;
44 
45  if (p->takeNextToken().content == QStringLiteral("else")) {
46  falseList = p->parse(n, QStringLiteral("endifchanged"));
47  n->setFalseList(falseList);
48  p->removeNextToken();
49  }
50 
51  return n;
52 }
53 
54 IfChangedNode::IfChangedNode(const QList<FilterExpression> &feList,
55  QObject *parent)
56  : Node(parent), m_filterExpressions(feList)
57 {
58  m_lastSeen = QVariant();
59  m_id = QString::number(reinterpret_cast<qint64>(this));
60 }
61 
62 void IfChangedNode::setTrueList(const NodeList &trueList)
63 {
64  m_trueList = trueList;
65 }
66 
67 void IfChangedNode::setFalseList(const NodeList &falseList)
68 {
69  m_falseList = falseList;
70 }
71 
73 {
74  if (c->lookup(QStringLiteral("forloop")).isValid()
75  && (!c->lookup(QStringLiteral("forloop"))
76  .value<QVariantHash>()
77  .contains(m_id))) {
78  m_lastSeen = QVariant();
79  auto hash = c->lookup(QStringLiteral("forloop")).value<QVariantHash>();
80  hash.insert(m_id, 1);
81  c->insert(QStringLiteral("forloop"), hash);
82  }
83 
84  QString watchedString;
85  QTextStream watchedTextStream(&watchedString);
86  auto watchedStream = stream->clone(&watchedTextStream);
87  if (m_filterExpressions.isEmpty()) {
88  m_trueList.render(watchedStream.get(), c);
89  }
90  QVariantList watchedVars;
91  for (auto &i : m_filterExpressions) {
92  auto var = i.resolve(c);
93  if (!var.isValid()) {
94  // silent error
95  return;
96  }
97  watchedVars.append(var);
98  }
99 
100  // In Qt6, QVariant::value<QVariantList>() converts a QString
101  // to a QList(QVariant(QChar, c)...).
102  // Avoid that conversion
103  QVariantList lastSeenVarList;
104  if (m_lastSeen.userType() != qMetaTypeId<QString>()) {
105  lastSeenVarList = m_lastSeen.value<QVariantList>();
106  }
107 
108  // At first glance it looks like m_last_seen will always be invalid,
109  // But it will change because render is called multiple times by the parent
110  // {% for %} loop in the template.
111  if ((watchedVars != lastSeenVarList)
112  || (!watchedString.isEmpty()
113  && (watchedString != m_lastSeen.value<QString>()))) {
114  auto firstLoop = !m_lastSeen.isValid();
115  if (!watchedString.isEmpty())
116  m_lastSeen = watchedString;
117  else
118  m_lastSeen = watchedVars;
119  c->push();
120  QVariantHash hash;
121  // TODO: Document this.
122  hash.insert(QStringLiteral("firstloop"), firstLoop);
123  c->insert(QStringLiteral("ifchanged"), hash);
124  m_trueList.render(stream, c);
125  c->pop();
126  } else if (!m_falseList.isEmpty()) {
127  m_falseList.render(stream, c);
128  }
129 }
QList< FilterExpression > getFilterExpressionList(const QStringList &list, Parser *p) const
Definition: node.cpp:192
The Context class holds the context to render a Template with.
Definition: context.h:119
void insert(const QString &name, QObject *object)
Definition: context.cpp:145
virtual QVariant lookup(const QString &str) const
Definition: context.cpp:100
A list of Nodes with some convenience API for rendering them.
Definition: node.h:148
void render(OutputStream *stream, Context *c) const
Definition: node.cpp:177
Base class for all nodes.
Definition: node.h:78
The OutputStream class is used to render templates to a QTextStream.
Definition: outputstream.h:81
virtual std::shared_ptr< OutputStream > clone(QTextStream *stream) const
The Parser class processes a string template into a tree of nodes.
Definition: parser.h:49
Token takeNextToken()
Definition: parser.cpp:291
NodeList parse(Node *parent, const QStringList &stopAt={})
Definition: parser.cpp:180
void removeNextToken()
Definition: parser.cpp:297
Node * getNode(const QString &tagContent, Parser *p) const override
Definition: ifchanged.cpp:29
void render(OutputStream *stream, Context *c) const override
Definition: ifchanged.cpp:72
QString content
The content of this Token.
Definition: token.h:51