Merge pull request #1141 from matthiasbeyer/libimaginteraction/more-helpers

libimaginteraction: Add more helpers for handlebars

imagrc.toml

@@ -1,6 +1,49 @@
 # This is a example configuration file for the imag suite.
 # It is written in TOML
 
+#
+# imag supports templates when specifying formats. The templates support several
+# functionalities, from colorizing to underlining and such things.
+#
+# Here goes a list of supported formatting helpers:
+#
+# These functions can be applied for colorizing the output:
+#  {{black <input>}}
+#  {{blue <input>}}
+#  {{cyan <input>}}
+#  {{green <input>}}
+#  {{purple <input>}}
+#  {{red <input>}}
+#  {{white <input>}}
+#  {{yellow <input>}}
+#
+# The following functions are allowed for formatting text:
+#  {{lpad <count> <input>}}   - to "left pad" by <count> spaces
+#  {{rpad <count> <input>}}   - to "right pad" by <count> spaces
+#  {{abbrev <count> <input>}} - to "abbreviate" the output to <count> chars
+#  {{underline <input>}}      - for underlining
+#  {{bold <input>}}           - for making input bold
+#  {{blink <input>}}          - for making input blinking
+#  {{strikethrough <input>}}  - for making input struck through
+#
+# Strings can only be printed. Arrays can be indexed with the `lookup` function.
+#
+#
+# The underlying templating engine also supports these:
+#
+# {{#raw}} ... {{/raw}} escape handlebars expression within the block
+# {{#if ...}} ... {{else}} ... {{/if}} if-else block
+# {{#unless ...}} ... {{else}} .. {{/unless}} if-not-else block
+# {{#each ...}} ... {{/each}} iterates over an array or object.
+#   Handlebar-rust doesn't support mustach iteration syntax so use this instead.
+# {{#with ...}} ... {{/with}} change current context. Similar to {{#each}}, used for replace corresponding mustach syntax.
+# {{lookup ... ...}} get value from array by @index or @key
+# {{> ...}} include template with name
+# {{log ...}} log value with rust logger, default level: INFO. Currently you cannot change the level.
+#
+# Warning: These are _not_ tested and should be used with care.
+#
+
 # The alias section
 #
 # In this section one can define aliases for imag subcommands.
@@ -19,6 +62,7 @@ store = [ "s", "st" ]
 level = "debug"
 destinations = [ "-" ]
 
+#
 # Valid variables for logging:
 #  * "level"
 #  * "module_path"
@@ -27,15 +71,6 @@ destinations = [ "-" ]
 #  * "target"
 #  * "message"
 #
-# Valid functions to be applied:
-#  * "black"
-#  * "blue"
-#  * "cyan"
-#  * "green"
-#  * "purple"
-#  * "red"
-#  * "white"
-#  * "yellow"
 
 [imag.logging.format]
 trace = "[imag][{{red level}}][{{module_path}}]: {{message}}"

lib/etc/libimaginteraction/Cargo.toml

@@ -23,6 +23,7 @@ regex = "0.2"
 toml = "0.4"
 error-chain = "0.11"
 handlebars = "0.29.0"
+serde_json = "1"
 
 libimagstore       = { version = "0.5.0", path = "../../../lib/core/libimagstore" }
 libimagerror       = { version = "0.5.0", path = "../../../lib/core/libimagerror" }

lib/etc/libimaginteraction/src/format.rs

@@ -18,6 +18,7 @@
 //
 
 use handlebars::{Handlebars, HelperDef, JsonRender, RenderError, RenderContext, Helper};
+use serde_json::value::Value;
 use ansi_term::Colour;
 use ansi_term::Style;
 
@@ -152,6 +153,51 @@ impl HelperDef for StrikethroughHelper {
         }
 }
 
+fn param_to_number(idx: usize, h: &Helper) -> Result<u64, RenderError> {
+    match try!(h.param(idx).ok_or(RenderError::new("Too few arguments"))).value() {
+        &Value::Number(ref num) => num.as_u64().ok_or_else(|| RenderError::new("Number cannot be parsed")),
+        _ => Err(RenderError::new("Type error: First argument should be a number")),
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct LeftPadHelper;
+
+impl HelperDef for LeftPadHelper {
+    fn call(&self, h: &Helper, _: &Handlebars, rc: &mut RenderContext) -> Result<(), RenderError> {
+        let count = param_to_number(0, h)? as usize;
+        let text = try!(h.param(1).ok_or(RenderError::new("Too few arguments")));
+        let text = format!("{:>width$}", text.value().render(), width = count);
+        try!(write!(rc.writer(), "{}", text));
+        Ok(())
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct RightPadHelper;
+
+impl HelperDef for RightPadHelper {
+    fn call(&self, h: &Helper, _: &Handlebars, rc: &mut RenderContext) -> Result<(), RenderError> {
+        let count = param_to_number(0, h)? as usize;
+        let text = try!(h.param(1).ok_or(RenderError::new("Too few arguments")));
+        let text = format!("{:width$}", text.value().render(), width = count);
+        try!(write!(rc.writer(), "{}", text));
+        Ok(())
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct AbbrevHelper;
+
+impl HelperDef for AbbrevHelper {
+    fn call(&self, h: &Helper, _: &Handlebars, rc: &mut RenderContext) -> Result<(), RenderError> {
+        let count = param_to_number(0, h)? as usize;
+        let text = try!(h.param(1).ok_or(RenderError::new("Too few arguments"))).value().render();
+        try!(write!(rc.writer(), "{}", text.chars().take(count).collect::<String>()));
+        Ok(())
+    }
+}
+
 pub fn register_all_color_helpers(handlebars: &mut Handlebars) {
     handlebars.register_helper("black"  , Box::new(ColorizeBlackHelper));
     handlebars.register_helper("blue"   , Box::new(ColorizeBlueHelper));
@@ -168,5 +214,8 @@ pub fn register_all_format_helpers(handlebars: &mut Handlebars) {
     handlebars.register_helper("bold"          , Box::new(BoldHelper));
     handlebars.register_helper("blink"         , Box::new(BlinkHelper));
     handlebars.register_helper("strikethrough" , Box::new(StrikethroughHelper));
+    handlebars.register_helper("lpad"          , Box::new(LeftPadHelper));
+    handlebars.register_helper("rpad"          , Box::new(RightPadHelper));
+    handlebars.register_helper("abbrev"        , Box::new(AbbrevHelper));
 }
 

lib/etc/libimaginteraction/src/lib.rs

@@ -42,6 +42,7 @@ extern crate regex;
 extern crate clap;
 extern crate toml;
 extern crate handlebars;
+extern crate serde_json;
 #[macro_use] extern crate error_chain;
 
 extern crate libimagstore;