Prompts from file support nodes (#3964)

* New classes to support the PromptsFromFileInvocation Class
- PromptPosNegOutput
- PromptSplitNegInvocation
- PromptJoinInvocation
- PromptReplaceInvocation

* - Added PromptsToFileInvocation,
- PromptSplitNegInvocation
  - now counts the bracket depth so ensures it cout the numbr of open and close brackets match.
  - checks for escaped [ ] so ignores them if escaped e.g \[
- PromptReplaceInvocation - now has a user regex. and no regex in made caseinsesitive

* Update prompt.py

created class PromptsToFileInvocationOutput and use it in PromptsToFileInvocation instead of BaseInvocationOutput

* Update prompt.py

* Added schema_extra title and tags  for PromptReplaceInvocation, PromptJoinInvocation,  PromptSplitNegInvocation and PromptsToFileInvocation

* Added PTFileds Collect and Expand

* update to nodes v1

* added ui_type to file_path for PromptToFile

* update params for the primitive types used, remove the ui_type filepath, promptsToFile now only accepts collections until a fix is available

* updated the parameters for the StringOutput primitive

* moved the prompt tools nodes out of the prompt.py into prompt_tools.py

* more rework for v1

* added github link

* updated to use "@invocation"

* updated tags

* Adde new nodes PromptStrength and PromptStrengthsCombine

* chore: black

* feat(nodes): add version to prompt nodes

* renamed nodes from prompt related to string related. Also moved them into a strings.py file.  Also moved and renamed the PromptsFromFileInvocation from prompt.py to strings.py.  The PTfileds still remain in the Prompt_tool.py for now.

* added , version="1.0.0" to the invocations

* removed the PTField related nodes and the prompt-tools.py file all new nodes now live in the

* formatted prompt.py and strings.py with Black and fixed silly mistake in the new StringSplitInvocation

* - Revert Prompt.py back to original
- Update strings.py to be only StringJoin, StringJoinThre, StringReplace, StringSplitNeg, StringSplit

* applied isort to imports

* fix(nodes): typos in `strings.py`

---------

Co-authored-by: psychedelicious <4822129+psychedelicious@users.noreply.github.com>
Co-authored-by: Millun Atluri <Millu@users.noreply.github.com>

invokeai/app/invocations/strings.py

@@ -0,0 +1,139 @@
+# 2023 skunkworxdark (https://github.com/skunkworxdark)
+
+import re
+
+from .baseinvocation import (
+    BaseInvocation,
+    BaseInvocationOutput,
+    InputField,
+    InvocationContext,
+    OutputField,
+    UIComponent,
+    invocation,
+    invocation_output,
+)
+from .primitives import StringOutput
+
+
+@invocation_output("string_pos_neg_output")
+class StringPosNegOutput(BaseInvocationOutput):
+    """Base class for invocations that output a positive and negative string"""
+
+    positive_string: str = OutputField(description="Positive string")
+    negative_string: str = OutputField(description="Negative string")
+
+
+@invocation(
+    "string_split_neg",
+    title="String Split Negative",
+    tags=["string", "split", "negative"],
+    category="string",
+    version="1.0.0",
+)
+class StringSplitNegInvocation(BaseInvocation):
+    """Splits string into two strings, inside [] goes into negative string everthing else goes into positive string. Each [ and ] character is replaced with a space"""
+
+    string: str = InputField(default="", description="String to split", ui_component=UIComponent.Textarea)
+
+    def invoke(self, context: InvocationContext) -> StringPosNegOutput:
+        p_string = ""
+        n_string = ""
+        brackets_depth = 0
+        escaped = False
+
+        for char in self.string or "":
+            if char == "[" and not escaped:
+                n_string += " "
+                brackets_depth += 1
+            elif char == "]" and not escaped:
+                brackets_depth -= 1
+                char = " "
+            elif brackets_depth > 0:
+                n_string += char
+            else:
+                p_string += char
+
+            # keep track of the escape char but only if it isn't escaped already
+            if char == "\\" and not escaped:
+                escaped = True
+            else:
+                escaped = False
+
+        return StringPosNegOutput(positive_string=p_string, negative_string=n_string)
+
+
+@invocation_output("string_2_output")
+class String2Output(BaseInvocationOutput):
+    """Base class for invocations that output two strings"""
+
+    string_1: str = OutputField(description="string 1")
+    string_2: str = OutputField(description="string 2")
+
+
+@invocation("string_split", title="String Split", tags=["string", "split"], category="string", version="1.0.0")
+class StringSplitInvocation(BaseInvocation):
+    """Splits string into two strings, based on the first occurance of the delimiter. The delimiter will be removed from the string"""
+
+    string: str = InputField(default="", description="String to split", ui_component=UIComponent.Textarea)
+    delimiter: str = InputField(
+        default="", description="Delimiter to spilt with. blank will split on the first whitespace"
+    )
+
+    def invoke(self, context: InvocationContext) -> String2Output:
+        result = self.string.split(self.delimiter, 1)
+        if len(result) == 2:
+            part1, part2 = result
+        else:
+            part1 = result[0]
+            part2 = ""
+
+        return String2Output(string_1=part1, string_2=part2)
+
+
+@invocation("string_join", title="String Join", tags=["string", "join"], category="string", version="1.0.0")
+class StringJoinInvocation(BaseInvocation):
+    """Joins string left to string right"""
+
+    string_left: str = InputField(default="", description="String Left", ui_component=UIComponent.Textarea)
+    string_right: str = InputField(default="", description="String Right", ui_component=UIComponent.Textarea)
+
+    def invoke(self, context: InvocationContext) -> StringOutput:
+        return StringOutput(value=((self.string_left or "") + (self.string_right or "")))
+
+
+@invocation("string_join_three", title="String Join Three", tags=["string", "join"], category="string", version="1.0.0")
+class StringJoinThreeInvocation(BaseInvocation):
+    """Joins string left to string middle to string right"""
+
+    string_left: str = InputField(default="", description="String Left", ui_component=UIComponent.Textarea)
+    string_middle: str = InputField(default="", description="String Middle", ui_component=UIComponent.Textarea)
+    string_right: str = InputField(default="", description="String Right", ui_component=UIComponent.Textarea)
+
+    def invoke(self, context: InvocationContext) -> StringOutput:
+        return StringOutput(value=((self.string_left or "") + (self.string_middle or "") + (self.string_right or "")))
+
+
+@invocation(
+    "string_replace", title="String Replace", tags=["string", "replace", "regex"], category="string", version="1.0.0"
+)
+class StringReplaceInvocation(BaseInvocation):
+    """Replaces the search string with the replace string"""
+
+    string: str = InputField(default="", description="String to work on", ui_component=UIComponent.Textarea)
+    search_string: str = InputField(default="", description="String to search for", ui_component=UIComponent.Textarea)
+    replace_string: str = InputField(
+        default="", description="String to replace the search", ui_component=UIComponent.Textarea
+    )
+    use_regex: bool = InputField(
+        default=False, description="Use search string as a regex expression (non regex is case insensitive)"
+    )
+
+    def invoke(self, context: InvocationContext) -> StringOutput:
+        pattern = self.search_string or ""
+        new_string = self.string or ""
+        if len(pattern) > 0:
+            if not self.use_regex:
+                # None regex so make case insensitve
+                pattern = "(?i)" + re.escape(pattern)
+            new_string = re.sub(pattern, (self.replace_string or ""), new_string)
+        return StringOutput(value=new_string)